Academic literature on the topic 'Induced systemic resistance (ISR)'
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Journal articles on the topic "Induced systemic resistance (ISR)"
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Acharya, R., P. Patra, N. Chakraborty, N. S. Gupta, and K. Acharya. "Footprint of Nitric oxide in induced systemic resistance." NBU Journal of Plant Sciences 7, no. 1 (2013): 55–61. http://dx.doi.org/10.55734/nbujps.2013.v07i01.008.
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Nitric oxide (NO) is a potent signaling molecule with diverse physiological functions in plants. Several rhizobacterial strains may have capacity to induce systemic resistance in (ISR) plants but how far the biochemical mechanisms in which No participates in this signaling pathway is still an open question. The present study have shown in Pseudomonas aeruginosa WS-1 mediated ISR inducing system in Catharanthus roseus induces defense enzyme and phenolics and also showed a two fold increase in NO production when challenge with Alternaria alternata. Furthermore, NO donor treatment in the host produced same defense molecules in a comparable manner. From those observations it is suggested that NO might have possible signaling role in ISR during crosstalk between the ISR inducing agent and pathogen within the host system.
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Van Wees, Saskia C. M., Corné M. J. Pieterse, Annemiek Trijssenaar, Yvonne A. M. Van 't Westende, Femke Hartog, and Leendert C. Van Loon. "Differential Induction of Systemic Resistance in Arabidopsis by Biocontrol Bacteria." Molecular Plant-Microbe Interactions® 10, no. 6 (August 1997): 716–24. http://dx.doi.org/10.1094/mpmi.1997.10.6.716.
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Selected nonpathogenic, root-colonizing bacteria are able to elicit induced systemic resistance (ISR) in plants. To elucidate the molecular mechanisms underlying this type of systemic resistance, an Arabidopsis-based model system was developed in which Pseudomonas syringae pv. tomato and Fusarium oxysporum f. sp. raphani were used as challenging pathogens. In Arabidopsis thaliana ecotypes Columbia and Landsberg erecta, colonization of the rhizosphere by P. fluorescens strain WCS417r induced systemic resistance against both pathogens. In contrast, ecotype RLD did not respond to WCS417r treatment, whereas all three ecotypes expressed systemic acquired resistance upon treatment with salicylic acid (SA). P. fluorescens strain WCS374r, previously shown to induce ISR in radish, did not elicit ISR in Arabidopsis. The opposite was found for P. putida strain WCS358r, which induced ISR in Arabidopsis but not in radish. These results demonstrate that rhizosphere pseudomonads are differentially active in eliciting ISR in related plant species. The outer membrane lipopolysaccharide (LPS) of WCS417r is the main ISR-inducing determinant in radish and carnation, and LPS-containing cell walls also elicit ISR in Arabidopsis. However, mutant WCS417rOA¯, lacking the O-antigenic side chain of the LPS, induced levels of protection similar to those induced by wild-type WCS417r. This indicates that ISR-inducing bacteria produce more than a single factor that trigger ISR in Arabidopsis. Furthermore, WCS417r and WCS358r induced protection in both wildtype Arabidopsis and SA-nonaccumulating NahG plants without activating pathogenesis-related gene expression. This suggests that elicitation of an SA-independent signaling pathway is a characteristic feature of ISR-inducing biocontrol bacteria.
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Bakker, Peter A. H. M., Corné M. J. Pieterse, and L. C. van Loon. "Induced Systemic Resistance by Fluorescent Pseudomonas spp." Phytopathology® 97, no. 2 (February 2007): 239–43. http://dx.doi.org/10.1094/phyto-97-2-0239.
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Fluorescent Pseudomonas spp. have been studied for decades for their plant growth-promoting effects through effective suppression of soilborne plant diseases. The modes of action that play a role in disease suppression by these bacteria include siderophore-mediated competition for iron, antibiosis, production of lytic enzymes, and induced systemic resistance (ISR). The involvement of ISR is typically studied in systems in which the Pseudomonas bacteria and the pathogen are inoculated and remain spatially separated on the plant, e.g., the bacteria on the root and the pathogen on the leaf, or by use of split root systems. Since no direct interactions are possible between the two populations, suppression of disease development has to be plant-mediated. In this review, bacterial traits involved in Pseudomonas-mediated ISR will be discussed.
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Verhagen, Bas W. M., Jane Glazebrook, Tong Zhu, Hur-Song Chang, L. C. van Loon, and Corné M. J. Pieterse. "The Transcriptome of Rhizobacteria-Induced Systemic Resistance in Arabidopsis." Molecular Plant-Microbe Interactions® 17, no. 8 (August 2004): 895–908. http://dx.doi.org/10.1094/mpmi.2004.17.8.895.
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Plants develop an enhanced defensive capacity against a broad spectrum of plant pathogens after colonization of the roots by selected strains of nonpathogenic, fluorescent Pseudomonas spp. In Arabidopsis thaliana, this rhizobacteria-induced systemic resistance (ISR) functions independently of salicylic acid but requires responsiveness to the plant hormones jasmonic acid and ethylene. In contrast to pathogen-induced systemic acquired resistance, rhizobacteria-mediated ISR is not associated with changes in the expression of genes encoding pathogenesis-related proteins. To identify ISR-related genes, we surveyed the transcriptional response of over 8,000 Arabidopsis genes during rhizobacteria-mediated ISR. Locally in the roots, ISR-inducing Pseudomonas fluorescens WCS417r bacteria elicited a substantial change in the expression of 97 genes. However, systemically in the leaves, none of the approximately 8,000 genes tested showed a consistent change in expression in response to effective colonization of the roots by WCS417r, indicating that the onset of ISR in the leaves is not associated with detectable changes in gene expression. After challenge inoculation of WCS417r-induced plants with the bacterial leaf pathogen P. syringae pv. tomato DC3000, 81 genes showed an augmented expression pattern in ISR-expressing leaves, suggesting that these genes were primed to respond faster or more strongly upon pathogen attack. The majority of the primed genes was predicted to be regulated by jasmonic acid or ethylene signaling. Priming of pathogen-induced genes allows the plant to react more effectively to the invader encountered, which might explain the broad-spectrum action of rhizobacteria-mediated ISR.
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Yu, Yiyang, Ying Gui, Zijie Li, Chunhao Jiang, Jianhua Guo, and Dongdong Niu. "Induced Systemic Resistance for Improving Plant Immunity by Beneficial Microbes." Plants 11, no. 3 (January 30, 2022): 386. http://dx.doi.org/10.3390/plants11030386.
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Plant beneficial microorganisms improve the health and growth of the associated plants. Application of beneficial microbes triggers an enhanced resistance state, also termed as induced systemic resistance (ISR), in the host, against a broad range of pathogens. Upon the activation of ISR, plants employ long-distance systemic signaling to provide protection for distal tissue, inducing rapid and strong immune responses against pathogens invasions. The transmission of ISR signaling was commonly regarded to be a jasmonic acid- and ethylene-dependent, but salicylic acid-independent, transmission. However, in the last decade, the involvement of both salicylic acid and jasmonic acid/ethylene signaling pathways and the regulatory roles of small RNA in ISR has been updated. In this review, the plant early recognition, responsive reactions, and the related signaling transduction during the process of the plant–beneficial microbe interaction was discussed, with reflection on the crucial regulatory role of small RNAs in the beneficial microbe-mediated ISR.
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Choudhary, Devendra K., Anil Prakash, and B. N. Johri. "Induced systemic resistance (ISR) in plants: mechanism of action." Indian Journal of Microbiology 47, no. 4 (December 2007): 289–97. http://dx.doi.org/10.1007/s12088-007-0054-2.
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Kloepper, Joseph W., Choong-Min Ryu, and Shouan Zhang. "Induced Systemic Resistance and Promotion of Plant Growth by Bacillus spp." Phytopathology® 94, no. 11 (November 2004): 1259–66. http://dx.doi.org/10.1094/phyto.2004.94.11.1259.
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Elicitation of induced systemic resistance (ISR) by plant-associated bacteria was initially demonstrated using Pseudomonas spp. and other gram-negative bacteria. Several reviews have summarized various aspects of the large volume of literature on Pseudomonas spp. as elicitors of ISR. Fewer published accounts of ISR by Bacillus spp. are available, and we review this literature for the first time. Published results are summarized showing that specific strains of the species B. amyloliquefaciens, B. subtilis, B. pasteurii, B. cereus, B. pumilus, B. mycoides, and B. sphaericus elicit significant reductions in the incidence or severity of various diseases on a diversity of hosts. Elicitation of ISR by these strains has been demonstrated in greenhouse or field trials on tomato, bell pepper, muskmelon, watermelon, sugar beet, tobacco, Arabidopsis sp., cucumber, loblolly pine, and two tropical crops (long cayenne pepper and green kuang futsoi). Protection resulting from ISR elicited by Bacillus spp. has been reported against leaf-spotting fungal and bacterial pathogens, systemic viruses, a crown-rotting fungal pathogen, root-knot nematodes, and a stem-blight fungal pathogen as well as damping-off, blue mold, and late blight diseases. Reductions in populations of three insect vectors have also been noted in the field: striped and spotted cucumber beetles that transmit cucurbit wilt disease and the silver leaf whitefly that transmits Tomato mottle virus. In most cases, Bacillus spp. that elicit ISR also elicit plant growth promotion. Studies on mechanisms indicate that elicitation of ISR by Bacillus spp. is associated with ultrastructural changes in plants during pathogen attack and with cytochemical alterations. Investigations into the signal transduction pathways of elicited plants suggest that Bacillus spp. activate some of the same pathways as Pseudomonas spp. and some additional pathways. For example, ISR elicited by several strains of Bacillus spp. is independent of salicylic acid but dependent on jasmonic acid, ethylene, and the regulatory gene NPR1—results that are in agreement with the model for ISR elicited by Pseudomonas spp. However, in other cases, ISR elicited by Bacillus spp. is dependent on salicylic acid and independent of jasmonic acid and NPR1. In addition, while ISR by Pseudomonas spp. does not lead to accumulation of the defense gene PR1 in plants, in some cases, ISR by Bacillus spp. does. Based on the strains and results summarized in this review, two products for commercial agriculture have been developed, one aimed mainly at plant growth promotion for transplanted vegetables and one, which has received registration from the U.S. Environmental Protection Agency, for disease protection on soybean.
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Lee Díaz, Ana Shein, Desiré Macheda, Haymanti Saha, Ursula Ploll, Dimitri Orine, and Arjen Biere. "Tackling the Context-Dependency of Microbial-Induced Resistance." Agronomy 11, no. 7 (June 25, 2021): 1293. http://dx.doi.org/10.3390/agronomy11071293.
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Plant protection with beneficial microbes is considered to be a promising alternative to chemical control of pests and pathogens. Beneficial microbes can boost plant defences via induced systemic resistance (ISR), enhancing plant resistance against future biotic stresses. Although the use of ISR-inducing microbes in agriculture seems promising, the activation of ISR is context-dependent: it often occurs only under particular biotic and abiotic conditions, thus making its use unpredictable and hindering its application. Although major breakthroughs in research on mechanistic aspects of ISR have been reported, ISR research is mainly conducted under highly controlled conditions, differing from those in agricultural systems. This forms one of the bottlenecks for the development of applications based on ISR-inducing microbes in commercial agriculture. We propose an approach that explicitly incorporates context-dependent factors in ISR research to improve the predictability of ISR induction under environmentally variable conditions. Here, we highlight how abiotic and biotic factors influence plant–microbe interactions in the context of ISR. We also discuss the need to raise awareness in harnessing interdisciplinary efforts between researchers and stakeholders partaking in the development of applications involving ISR-inducing microbes for sustainable agriculture.
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van Loon, Leendert C., Peter A. H. M. Bakker, Walter H. W. van der Heijdt, David Wendehenne, and Alain Pugin. "Early Responses of Tobacco Suspension Cells to Rhizobacterial Elicitors of Induced Systemic Resistance." Molecular Plant-Microbe Interactions® 21, no. 12 (December 2008): 1609–21. http://dx.doi.org/10.1094/mpmi-21-12-1609.
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Colonization of roots by selected strains of fluorescent Pseudomonas spp. can trigger induced systemic resistance (ISR) against foliar pathogens in a plant species-specific manner. It has been suggested that early responses in cell suspension cultures in response to rhizobacterial elicitors, such as generation of active oxygen species (AOS) and extracellular medium alkalinization (MA), are linked to the development of ISR in whole plants. Perception of flagellin was demonstrated to elicit ISR in Arabidopsis, and bacterial lipopolysaccharides (LPS) have been shown to elicit several defense responses and to act as bacterial determinants of ISR in various plant species. In the present study, the LPS-containing cell walls, the pyoverdine siderophores, and the flagella of Pseudomonas putida WCS358, P. fluorescens WCS374, and P. fluorescens WCS417, which are all known to act as elicitors of ISR in selected plant species, were tested for their effects on the production of AOS, MA, elevation of cytoplasmic Ca2+ ([Ca2+]cyt), and defense-related gene expression in tobacco suspension cells. The LPS of all three strains, the siderophore of WCS374, and the flagella of WCS358 induced a single, transient, early burst of AOS, whereas the siderophores of WCS358 and WCS417 and the flagella of WCS374 and WCS417 did not. None of the compounds caused cell death. Once stimulated by the active compounds, the cells became refractory to further stimulation by any of the active elicitors, but not to the elicitor cryptogein from the oomycete Phytophthora cryptogea, indicating that signaling upon perception of the different rhizobacterial compounds rapidly converges into a common response pathway. Of all compounds tested, only the siderophores of WCS358 and WCS417 did not induce MA; the flagella of WCS374 and WCS417, although not active as elicitors of AOS, did induce MA. These results were corroborated by using preparations from relevant bacterial mutants. The active rhizobacterial elicitors led to a rapid increase in [Ca2+]cyt, peaking at 6 min, whereas the inactive siderophores of WCS358 and WCS417 elicited a single spike at 1 min. Elicitation of the cells by cell-wall LPS of WCS358 or the siderophore of WCS374 induced a weak, transient expression of several defense-related genes, including PAL and GST. The spectrum of early responses of the suspension cells was not matched by the expression of ISR in whole tobacco plants against Erwinia carotovora pv. carotovora. Of the live bacterial strains, only WCS358 elicited significant ISR, but application of the LPS or the siderophore of all three strains also elicited ISR. Notably, the absence of elicitation of AOS and MA in suspension-cultured cells but induction of ISR in whole plants by the siderophore of WCS358, which was lost upon treatment with the siderophore-minus mutant of WCS358, indicates that the early responses in suspension cells are not predictive of the ability to induce ISR in whole plants. Possible explanations for these discrepancies are discussed.
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Xie, Shanshan, Hengguo Yu, Enze Li, Yu Wang, Juan Liu, and Haiyang Jiang. "Identification of miRNAs Involved in Bacillus velezensis FZB42-Activated Induced Systemic Resistance in Maize." International Journal of Molecular Sciences 20, no. 20 (October 12, 2019): 5057. http://dx.doi.org/10.3390/ijms20205057.
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Bacillus velezensis FZB42 is able to activate induced systemic resistance (ISR) to enhance plant defense response against pathogen infections. Though the roles of microRNAs (miRNAs) in Bacillus-triggered ISR have been reported in Arabidopsis, the maize miRNAs responsible for the Bacillus-activated ISR process have not been discovered. To explore the maize miRNAs involved in ISR, maize miRNAs in response to FZB42 (ISR activating), FZB42△sfp△alss (deficient in triggering ISR), and a control for 12 h were sequenced. A total of 146 known miRNAs belonging to 30 miRNA families and 217 novel miRNAs were identified. Four miRNAs specifically repressed in FZB42-treatment were selected as candidate ISR-associated miRNAs. All of them contained at least one defense response-related cis-element, suggesting their potential roles in activating the ISR process. Interestingly, three of the four candidate ISR-associated miRNAs belong to the conserved miR169 family, which has previously been confirmed to play roles in abiotic stress response. Moreover, 52 mRNAs were predicted as potential targets of these candidate ISR-associated miRNAs through TargetFinder software and degradome sequencing. Gene Ontology (GO) and network analyses of target genes showed that these differentially expressed miRNA might participate in the ISR process by regulating nuclear factor Y transcription factor. This study is helpful in better understanding the regulatory roles of maize miRNAs in the Bacillus-activated ISR process.
Dissertations / Theses on the topic "Induced systemic resistance (ISR)"
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Muzammil, Saima. "Saccharothrix algeriensis NRRL B-24137 : biocontrol properties, colonization and induced systemic resistance towards Botrytis cinerea on grapevine and Arabidopsis thaliana." Thesis, Toulouse, INPT, 2012. http://www.theses.fr/2012INPT0063/document.
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Au cours de cette thèse, un isolat de sol de désert, Saccharothrix algeriensis NRRL B-24137, a été évalué pour ses propriétés bioactives contre le champignon phytopathogène Botrytis cinerea, pour sa colonization sur Vitis vinifera L., et Arabidopsis thaliana ainsi qu’en vue d’étudier les méchanismes de résistance systémique induite (ISR) contre B. cinerea. Les résultats obtenus nous ont permis premièrement de montrer que Sa. algeriensis NRRL B-24137 peut présenter des activités antifongiques contre B. cinerea et que des métabolites peuvent être responsables de cette activité antifongique. Bien que ces métabolites soient encore en cours d’étude et que cette étude mérite d’être approfondie, nous avons démontré ensuite les propriétés de colonisation de l’isolat du sol du désert chez la vigne. Les résultats ont permis de montrer que la souche peut former des populations rhizosphèriques ainsi que des sous-populations endophytiques chez des plants de vigne (Cabernet Sauvignon sur porte-greffe 44-53 M) à des étapes précoces de colonisation. Puis nous avons démontré que la souche bénéfique peut induire une résistance systémique contre B. cinerea. Bien que les mécanismes impliqués ne soient pas encore compris, des parties préliminaires de ces travaux démontrent que les expressions de gènes responsables de la production de glucanase, chitinase ainsi qu’un inhibiteur de polygalacturonase ne semblent pas potentialisés pendant le phénomène de résistance systémique. Enfin nous avons démontré l’interaction entre Sa. algeriensis NRRL B-24137 et Arabidopsis thaliana qui résulte dans une association intime dûe également à colonisation rhizosphèrique et endophytique de la plante modèle. La souche bénéfique peut églement induire un phénomène de résistance systémique sur A. thaliana contre B. cinerea et les analyses de plantes mutées ont permis de determiner des parties des mécanismes impliqués dans l’ISR aini que des nouveaux mécanismes impliqués qui peuvent être induits par des microbes bénéfiquesIn this thesis, the desert soil isolate, Saccharothrix algeriensis NRRL B-24137, has been evaluated for its bioactive properties towards the phytopathogenic fungus Botrytis cinerea, for its colonization of Vitis vinifera L., and Arabidopsis thaliana as well as to study the mechanisms of induced systemic resistance (ISR) towards B. cinerea. The results obtained allowed us firstly to show that Sa. algeriensis NRRL B-24137 can exhibit strong antifungal properties towards B. cinerea and that some metabolites can be responsible of this antifungal activity. Although these metabolites are still under consideration and that this study needs further works, we have demonstrated then the colonization properties of the desert soil isolate with grapevine plants. The results showed that the strain can form rhizospheric as well as endophytic subpopulations with grapevine plants (Cabernet Sauvignon cultivar graffed on 44-53 M rootstock) at early step of colonization. Then we have demonstrated that the beneficial strain could induce a systemic resistance towards B. cinerea. Although the mechanisms are not yet well understood, preliminary parts of this work demonstrated that the genes responsible of glucanase production, chitinase as well as inhibitor of polygalacturonase activity do not seems to be primed during the systemic resistance phenomenon. Finally we demonstrated that the interaction between Sa. algeriensis NRRL B-24137 and Arabidopsis thaliana plants results in a close association due also to a rhizo- and endophytic colonization of the model plant. The beneficial strain can also induce a systemic resistance in A. thaliana towards B. cinerea and analyzes of plant mutants have allowed to determine parts of the mechanisms involved in ISR as well as new mechanisms that could be trigerred by beneficial microbes
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SHAHZAD, GUL I. RAYNA. "BIOCONTROL STRATEGIES AGAINST PLANT PATHOGENS." Doctoral thesis, Università degli Studi di Milano, 2021. http://hdl.handle.net/2434/850186.
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It is a known fact that the whole agriculture system is suffering from the diseases caused by plant pathogens, affecting negatively the crop yield production, food security, biodiversity, agricultural ecosystem and hence agricultural economy. In many countries, the containment strategies of plant pathogens are still depending on chemical pesticides that cause adverse effects in the long term. According to the implementations reinforced by European council 2009/128/EC, biocontrol strategies are considered as the most profound and integrated approach for sustainable disease management. Defining biocontrol in terms of plant pathology, it is the purposeful utilization of beneficial microbes, or its molecules, to suppress phytopathogens’ ability to colonize or induce symptoms in the host. In spite of their lesser shelf-life and unreliability as compared to conventional pesticides, their targeted biological interaction with the phytopathogens reduces the possibility of affecting non-target organisms, environment and the development of resistance in the pathogen.
In this context, exploitation of bacterial endophytes has gained much attention during the past decades. Endophytic plant growth promoting bacteria (ePGPBs) mediate their biocontrol efficacy by targeting species through a multitude of direct or indirect biological interactions, often employing both modes of action, such as plant growth promotion, host’s resistance induction, allelochemicals secretion, and nutrients and niche competition. Another strategy that has gained popularity is the exogenous application of double stranded RNA (dsRNA), which is considered as the key trigger molecule of RNA interreference (RNAi), a post-transcriptional gene silencing mechanism, and has been shown to provide protection without the need for integration of dsRNA-expressing constructs as transgenes.
In the present doctoral thesis, the above-mentioned biocontrol strategies were adapted, utilizing “ePGPBs as microbial inoculants” and “exogenously applied dsRNA as RNAi based natural product”, against several phytopathogens belonging to different families of viruses and fungi.
Regarding ePGBPs as microbial inoculants, the objective of this study was to extend our understanding of five endophytic bacterial strains; Pantoea agglomerans (255-7), Pseudomonas syringae (260-02), Lysinibacillus fusiformis (S4C11), Paraburkholderia fungorum (R8), Paenibacillus pasadenensis (R16); that have shown a promising result in previous studies. In the present doctoral study, these strains were tested in planta to evaluate their role in providing plant growth promotion and broad-spectrum protection against two target pathosystems (viruses and fungi) that might have direct, indirect or simultaneous effects,
proceeded with two following aims: (Aim 1) action against viruses: Cymbidium ringspot virus (CymRSV), Cucumber mosaic virus (CMV), Potato virus X (PVX), and Potato virus Y (PVY) on Nicotiana benthamiana plants, comparing their effects with those of three chitosan-based products, which are known to induce resistance in plants; and (Aim 2) action against fungal pathogens: Rhizoctonia solani, Pythium ultimum and Botrytis cinerea on Lactuca sativa plants, comparing their effects with Bacillus amyloliquefaciens strain (CC2) and Trichoderma spp. based product, under controlled conditions.
To test the priming efficacy of ePGPBs against target viruses, several phenotypic parameters were observed along with the evaluation of three plant defense related genes (EDS1, PR2B and NPR1) on Nicotiana benthamiana plants. Interestingly, the symptoms reduction was successfully registered against CymRSV and CMV with increased heights of the plants. Some of the treatments were shown correlation between severity of symptoms and the virus concentration in the plants. Furthermore, the molecular interaction indicated the involvement of a salicylic acid (SA) mediated defense pathway as evidenced by the increased expression levels of EDS1 gene in strains R16 and 260-02. Whereas, strain S4C11 showed downregulation of PR2B gene, suggesting that SA-independent pathways could be involved. These findings opened queries regarding the duration of the protective effect, host-plant- pathogen interaction, and epidemiological implications of the use of similar biocontrol strains, that reduce the symptoms but not the concentration of virus in the host.
To test the ePGPBs role against target fungi (pre- and post-harvest stage), several experiments were conducted including phenotypic paraments, gene expression analysis (PR1, PAL, ThlP3, ERF1 and ACCS1), microbiota analysis in bulk soil, rhizosphere, and root associated with Lactuca sativa in the presence or absence of the inoculants, and nutritional quality parameters at time of harvest and during shelf-life of Romaine lettuce. The results were accompanied in terms of symptoms reduction by strain R16 (P. ultimum, R. solani, B. cinerea) and strain 260-02 (R. solani, B. cinerea); % seed germination by strains R16, 260-02, 255-7, S4C11 in some healthy and R. solani infected lettuce varieties; inhibition of R. solani population in soil and rhizosphere soil by strains R16, 260-02 and 255-7. Furthermore, composition of the bacterial microbiota was radically different in the rhizosphere and the root endosphere among treatments, while the bulk soil formed a single cluster regardless of treatment, indicating that the use of these treatments did not have an ecological impact outside of the plant. Also, these strains were able to contribute to the maintenance of nutritional quality indexes of lettuce at harvest and during storage. All the obtained results indicated that these
strains were involved directly (via antibiosis) and indirectly (via SA or ET/JA) in the observed reduction of symptoms. Particularly, strain R16 upregulated both PAL and ACCS1 gene in R. solani infected L. sativa (suggesting co-activation of SA- and JA/ ET mediated ISR resistance); strain 260-02 upregulated PAL gene in R. solani infected romaine lettuce and showed higher levels of ascorbic acid (AsA) production in B. cinerea infected romaine lettuce (suggesting the activation of SA- and AsA-mediated antioxidant resistance); and strain 255-7 triggered PAL and ThlP3 gene up-stream expression levels indicating SA mediated pathways in R. solani infected romaine lettuce. These findings affirmed the previous conclusions and added valuable pieces of information regarding the traits these ePGPB carried, most importantly, in individuating different mode of action of the different strains in different host plants with or without the presence of pathogen.
Regarding the second approach, non-transgenic strategy was employed to induce resistance against Tomato Aspermy Virus (TAV) in N. benthamiana plants. DsRNA molecules for coat protein (CP) gene was produced by a two-step PCR assay followed by in vitro transcription and purification and was exogenously applied. The implementation of CP-derived dsRNA TAV was not successful in reducing observed symptoms (mosaics, blisters, crinkling, leaf distortion, and systemic vein clearing), regardless of treatments or days of post inoculation. Only a slight difference was found in plant heights indicating that the treatment managed to reduce stunted growth of the plant at dilution 01:10 (6 and 12 dpi). The reasons could involve inappropriate concentration of dsRNA inoculum. Therefore, future studies will be conducted to optimize in vitro dsRNA molecules production to obtain higher concentrations or more specific sequences, and more suitable viral genes.
Both strategies have shown interesting outcomes and gave us the future direction which will help us in designing the adequate trials (in planta or semi-field) for the disease management and diseases control through the application of ePGPBs as a microbial inoculants and dsRNA-based product individually or in combination.
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Tripathi, Diwaker. "Role of SABP2 in Systemic Acquired Resistance Induced by Acibenzolar-S-Methyl in Plants." Digital Commons @ East Tennessee State University, 2010. https://dc.etsu.edu/etd/1720.
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Plants have evolved an efficient mechanism to defend themselves against pathogens. Many biotic and abiotic agents have been shown to induce defense mechanism in plants. Acibenzolar-S-Methyl (ASM) is a commercially available chemical inducer of local and systemic resistance (SAR) response in plants. ASM functioning at molecular level is mostly unclear. This research was designed to investigate the mechanism of ASM action in plants. It was hypothesized that SABP2, a plant protein, plays an important role in ASM-mediated defense signaling. Biochemical studies were performed to test the interaction between SABP2 and ASM. Transgenic SABP2-silenced tobacco plants were used to determine the role of SABP2 in SAR induced by ASM. The expression of PR-1 proteins was used as a marker for SAR induction. Results showed that SABP2 converts ASM into acibenzolar that induces the expression of PR-1 proteins and develops the SAR response in ASM-treated plants.
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Le, Thanh Toan, Van Dien Luong, Thi Thuy Nhien Ngo, and Van Kim Pham. "Induced systemic resistance against rice grassy stunt virus – a promising field for ecological rice production." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2012. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-88491.
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Most rice protection methods have currently used toxic chemicals to control pathogens and pests, which leads to environmental pollution. Systemic acquired resistance (SAR) taking advantage of natural defence reaction of plants could be proposed as an alternative, ecologically friendly approach for plant protection. Its application into rice production could minimize the chemicals quantity used and could contribute to the decrease of environmental pollution and the development of sustainable agriculture. The research was conducted to select the most effective chemical and suitable method to improve the health of rice plants infected by grassy stunt disease in net-house of Can Tho University. SAR chemicals were used at very low concentrations (in mM). Results showed that the height of rice plants treated with SAR chemicals was higher than that of plants untreated. Besides, the number of diseased plants was reduced and the ratio of firm grain and yield increased when plants were applied by SAR. Among the used substances, oxalic acid provided the best systemic acquired resistance. With oxalic acid, seed soaking was better than seed coating in systemic acquired resistance against rice grassy stunt diseaseHầu hết các phương pháp sản xuất lúa hiện nay đều sử dụng các hóa chất độc hại trong việc phòng trừ bệnh và côn trùng gây hại, nên dẫn đến ô nhiễm môi trường. Kích thích tính kháng lưu dẫn giúp kích hoạt cơ chế tự nhiên kháng bệnh của cây có thể là giải pháp bảo vệ thực vật thay thế an toàn với môi trường. Việc ứng dụng tiến bộ này vào trong sản xuất lúa có thể làm giảm lượng hóa chất sử dụng, đóng góp vào việc giảm thiểu ô nhiễm môi trường và sự phát triển của một nền nông nghiệp bền vững. Nghiên cứu đã được thực hiện tại nhà lưới trường Đại học Cần Thơ để tuyển chọn hóa chất và phương pháp sử dụng hóa chất để tăng cường sức khỏe giúp cây lúa vượt qua bệnh vàng lùn. Hóa chất kích kháng được sử dụng ở một nồng độ rất thấp (đơn vị là mM). Kết quả cho thấy chiều cao cây lúa khi xử lý chất kích kháng tốt hơn so đối chứng không xử lý. Bên cạnh đó, số cây lúa nhiễm bệnh giảm, tỉ lệ hạt chắc và năng suất tăng khi cây lúa được xử lý với chất kích kháng. Trong số các chất kích kháng đã sử dụng, acid oxalic cho hiệu quả vượt trội. Với chất acid oxalic, phương pháp ngâm hạt cho hiệu quả kích kháng tốt hơn phương pháp áo hạt
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Chen, Chunquan. "Induced systemic resistance against Pythium aphanidermatum by plant growth-promoting rhizobacteria on cucumber, Cucumis sativus L." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/NQ50129.pdf.
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Chen, Chunquan 1958. "Induced systemic resistance against Pythium aphanidermatum by plant growth-promoting rhizobacteria on cucumber (Cucumis sativus L.)." Thesis, McGill University, 1998. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=35862.
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Cucumber root rot caused by Pythium aphanidermatum can be suppressed by introduced plant growth-promoting rhizobacteria (PGPR). Preliminary experiments clarified that this root disease could be suppressed by strains of Pseudomonas aureofaciens, P. corrugata, and P. fluorescens. To determine whether the mechanism was a systemic resistance induced by PGPR, a split root technique was employed on greenhouse cucumbers grown in soilless substrates. On the split roots, bacteria which were introduced into one side of the root were completely separated from pathogen challenged-inoculated roots-on the other side of the roots. Results from the series of experiments conducted with this design demonstrated that (i) the resistance against root rot induced by PGPR was systemic, (ii) germination of P. aphanidermatum zoospores was reduced in extracts from bacterized roots compared to non-treated control, and (iii) spread of Pythium mycelia was delayed and zoospore germination was inhibited on the distant induced root, compared to the non-bacterized control. Furthermore, enzyme analysis indicated that phenylalanine ammonia lyase, peroxidase and polyphenoloxidase increased on cucumber roots two days after they were bacterized with Pseudomonas strains 13 or 63--28. When the bacterized roots were challenged with P. aphanidermatum, these plant defense enzymes increased as the symptoms appeared, but this accumulation of enzymes was not any higher on roots induced with each of the Pseudomonas strains compared to the Pythium inoculated control. This enzyme stimulation was also systemically induced by PGPR or P. aphanidermatum on cucumber roots. The patterns of iso-peroxidase induced with the PGPR and P. aphanidermatum treatments were different. High levels of salicylic acid (SA) accumulated in bacteria-induced roots, as well as in pathogen-infected roots, which suggests that SA may be associated with cucumber resistance response. But exogenous application of SA did not induce any systemi
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Borlinghaus, Maria Theresia. "Implications of biochar on UK barley systems : a biological perspective." Thesis, University of Edinburgh, 2015. http://hdl.handle.net/1842/17621.
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Biochar is the solid, carbon-rich by-product obtained from pyrolysis. It offers the prospect of long-term carbon sequestration and soil conditioning with agronomic benefits, often referred to as the ‘biochar effect‘. These multiple direct or indirect changes in the soil plant interface have also been associated with the control of plant diseases by influencing the host’s systemic induced resistance. The biological impact of biochar on the phytopathology of a major cereal grain has not yet been investigated. The most damaging foliar disease of barley in the UK is Rhynchosporium leaf blotch caused by the hemibiotrophic fungal pathogen Rhynchosporium commune. The aim of this project was to evaluate biochar performance and effectiveness as a disease control agent in the barley – R. commune – pathosystem, and attempted to identify underlying mechanisms by which biochar may function in the interaction between barley and the causal pathogen. Therefore, a unique set of nine slow pyrolysis biochars were established along a 350 to 800°C pyrolysis temperature gradient, with eight of these made from pelleted softwoods and a single one made from Miscanthus straw. A comprehensive biochar quality assessment was undertaken and established that the biochars differed in their chemical composition, which largely depended on production parameters, predominantly temperature (P < 0.05). The analysis proposed that biochar 9, made from Miscanthus at 800°C, showed added value as a soil conditioner over softwood biochars, due to higher pH, mineral ash and macronutrient recoveries, which pointed towards a possible liming potential. Regardless of the feedstock, biochars pyrolysed above 600°C indicated potential use for carbon sequestration purposes, due to higher carbon stability. Short-term controlled bioassays showed significant restricted growth of R. commune mycelium on defined medium to direct (1.0% w/w) and indirect volatile exposure from certain biochars (P < 0.001). The findings suggested a synergistic effect of the softwood biochars acidic nature and presence of fungicidal compounds, with observed inhibition of 100% attributed to re-condensation of tarry vapours onto biochar surfaces during pyrolysis. Qualitative biochar volatile organic compound analysis was conducted and identified biocide active phenolic and organic acid compounds, similar to those commonly found in smoke, bio-oils or wood vinegars. These findings proposed possible application for mitigation of inoculum pressure in field-grown barley, but the toxic nature of volatiles raised concerns over risks to human and environmental health, as also evidenced by detrimental barley growth effects. Subsequent controlled in vivo and in planta experiments revealed significant (P < 0.05) symptomatic barley leaf blotch reduction effects of up to 100%, following 5% (w/w) application of biochars 4, 5, 8 and 9. Barley plants transcriptional changes in ISR-dependent LOX2 and SAR-dependent PR1-b expression in planta verified systemic induced resistance as mechanisms behind the significant disease suppression of barley plants grown in soil amended with biochar 5 and 8. Disease reduction and biochar mediated induced resistance was attributed to either low concentrations of phytotoxic compounds, a direct toxicity effect from fungicidal compounds or indirect promotion of beneficial microbes. The results provided evidence, that in the case of the studied pathosystem, there is potential for biochar with specific characteristics to be considered as a soil amendment, offering not only carbon sequestration, but also possible improved disease resistance.
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Conn, Vanessa Michelle, and vanessa conn@acpfg com au. "Molecular Interactions of Endophytic Actinobacteria in Wheat and Arabidopsis." Flinders University. School of Medicine, 2006. http://catalogue.flinders.edu.au./local/adt/public/adt-SFU20060320.171412.
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Wheat is the most economically important crop forming one quarter of Australian farm production. The wheat industry is severely affected by diseases, with fungal pathogens causing the most important economic losses in Australia. The application of fungicides and chemicals can control crop diseases to a certain extent, however, it is expensive and public concern for the environment has led to alternative methods of disease control to be sought, including the use of microorganisms as biological control agents. Microorganisms are abundant in the soil adjacent to plant roots (rhizosphere) and within healthy plant tissue (endophytic) and a proportion possess plant growth promotion and disease resistance properties.
Actinobacteria are gram-positive, filamentous bacteria capable of secondary metabolite production such as antibiotics and antifungal compounds. A number of the biologically active endophytes belonging to the Actinobacteria phylum were isolated in our laboratory. A number of these isolates were capable of suppressing the wheat fungal pathogens Rhizoctonia solani, Pythium sp. and Gaeumannomyces graminis var. tritici, both in vitro and in planta indicating the potential for the actinobacteria to be used as biocontrol agents. The aim of this research was to investigate the molecular mechanisms underlying this plant-microbe interaction.
The indigenous microbial populations present in the rhizosphere and endophytic environment are critical to plant health and disruptions of these populations are detrimental. The culture-independent technique Terminal Restriction Fragment Length Polymorphism (T-RFLP) was used to characterise the endophytic actinobacteria population of wheat roots under different conditions. Soils which support a higher number of indigenous microorganisms result in wheat roots with higher endophytic actinobacterial diversity and level of colonisation. Sequencing of 16S rRNA gene clones, obtained using the same actinobacteria-biased PCR primers that were used in the T-RFLP analysis, confirmed the presence of the actinobacterial diversity, and identified a number of Mycobacterium and Streptomyces species. It was found that the endophytic actinobacterial population of the wheat plants contained a higher diversity of endophytic actinobacteria than reported previously, and that this diversity varied significantly among different field soils.
The endophytic actinobacteria have previously been shown to protect wheat from disease and enhance growth when coated onto the seed before sowing. As the endophytes isolated were recognised as potential biocontrol agents, the impact on the indigenous endophytic microbial population was investigated. Utilising the T-RFLP technique it was established that the use of a commercial microbial inoculant, containing a large number of soil bacterial and fungal strains applied to the soil, disrupts the indigenous endophyte population present in the wheat roots. The hypothesis is that non-indigenous microbes proliferate and dominate in the soil preventing a number of endophytic-competent actinobacterial genera from access to the seed and ultimately endophytic colonisation of the wheat roots. This dramatically reduces diversity of endophytes and level of colonisation. In contrast the use of a single endophytic actinobacteria endophyte inoculant results in a 3-fold increase in colonisation by the added inoculant, but does not significantly affect this indigenous population.
Colonisation of healthy plant tissues with fungal endophytes has been shown to improve the competitive fitness with enhanced tolerance to abiotic and biotic stress and improved resistance to pathogens and herbivores. In this study the fungal endophyte population of wheat plants grown in four different soils was analysed using partial sequencing of 18S rRNA gene sequences. Sequence anlaysis of clones revealed a diverse range of fungal endophytes. In this diverse range of fungal endophytes a number sequences were highly similar to those of previously known fungal phytopathogens. A number of sequences detected were similar to fungal species previously identified in soil or plant material but not as endophytes. The remaining sequences were similar to fungal species without a known relationship with plants.
Plants have developed an inducible mechanism of defence against pathogens. In addition to local responses plants have developed a mechanism to protect uninfected tissue through a signal that spreads systemically inducing changes in gene expression. In the model plant Arabidopsis thaliana activation of the Systemic Acquired Resistance (SAR) pathway and the Jasmonate (JA)/Ethylene (ET) pathway is characterised by the production of pathogenesis-related (PR) and antimicrobial proteins resulting in systemic pathogen resistance. Endophytic actinobacteria, isolated from healthy wheat roots in our laboratory, have been shown to enhance disease resistance to multiple pathogens in wheat when coated onto the seed before sowing. Real Time RT-PCR was used to determine if key genes in the SAR and JA/ET pathways were induced in response to inoculation with endophytic actinobacteria.
Inoculation of wild-type Arabidopsis thaliana with selected strains of endophytic actinobacteria was able to �prime� the defence pathways by inducing low level expression of SAR and JA/ET genes. Upon pathogen infection the defence-genes are strongly up-regulated and the endophyte coated plants had significantly higher expression of these genes compared to un-inoculated plants. Resistance to the bacterial pathogen Erwinia carotovora subsp. carotovora was mediated by the JA/ET pathway whereas the fungal pathogen Fusarium oxysporum triggered primarily the SAR pathway.
Further analysis of the endophytic actinobacteria-mediated resistance was performed using the Streptomyces sp. EN27 and Arabidopsis defence-compromised mutants. It was found that resistance to E. carotovora subsp. carotovora mediated by Streptomyces sp. EN27 occurred via a NPR1-independent pathway and required salicylic acid whereas the jasmonic acid and ethylene signalling molecules were not essential. In contrast resistance to F. oxysporum mediated by Streptomyces sp. EN27 occurred via a NPR1-dependent pathway but also required salicylic acid and was JA- and ET-independent.
This research demonstrated that inoculating wheat with endophytic actinobacteria does not disrupt the indigenous endophytic population and may be inducing systemic resistance by activating defence pathways which lead to the expression of antimicrobial genes and resistance to a broad range of pathogens.
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Chanda, Bidisha. "GLYCEROL-3-PHOSPHATE IS A NOVEL REGULATOR OF BASAL AND INDUCED DEFENSE SIGNALING IN PLANTS." UKnowledge, 2012. http://uknowledge.uky.edu/plantpath_etds/16.
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Plants use several strategies to defend themselves against microbial pathogens. These include basal resistance, which is induced in response to pathogen encoded effector proteins, and resistance (R) protein-mediated resistance that is activated upon direct or indirect recognition of pathogen encoded avirulence protein(s). The activation of Rmediated signaling is often associated with generation of a signal, which, upon its translocation to the distal uninfected parts, confers broad-spectrum immunity against related or unrelated pathogens. This phenomenon known as systemic acquired resistance (SAR) is one of the well-established forms of induced defense response. However, the molecular mechanism underlying SAR remains largely unknown. Induction of plant defense is often associated with a fitness cost, likely because it involves reprogramming of the energy-providing metabolic pathways. Glycerol metabolism is one such pathway that feeds into primary metabolism, including lipid biosynthesis. In this study, I evaluated the role of glycerol-3-phosphate (G3P) in host-pathogen interaction. Inoculation with the hemibiotrophic fungal pathogen Colletotrichum higginsianum led to increased accumulation of G3P in wild-type plants. Mutants impaired in biosynthesis of G3P showed enhanced susceptibility, suggesting a correlation between G3P levels and basal defense. Conversely, increased biosynthesis of G3P correlated with enhanced resistance. The Arabidopsis genome encodes one copy of glycerol kinase (GK), which catalyzes phosphorylation of glycerol to G3P, and five copies of G3P dehydrogenase (G3Pdh), which catalyze reduction of dihydroxyacetone phosphate to G3P. Analysis of plants mutated in various G3Pdh's showed that plastidal lipid biosynthesis was only dependent on the GLY1 isoform but the pathogen induced G3P pool required the function of GLY1 and two other G3Pdh isoforms. Interestingly, compromised G3P biosynthesis in GK and G3Pdh mutants also compromised SAR, which was restored when G3P was provided exogenously. Detailed biochemical analysis showed that G3P was transported to distal tissues and that this process was dependent on a lipid transfer protein, DIR1. Together, these results show that G3P plays an important role in both basal- and induced-defense responses.
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Zhang, Weizheng. "Disease suppression and systemic-acquired-resistance-induced in plants by compost-amended potting mixes, compost water extracts and no-tillage soil /." The Ohio State University, 1997. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487943610784806.
Full textBooks on the topic "Induced systemic resistance (ISR)"
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Choudhary, Devendra K., and Ajit Varma, eds. Microbial-mediated Induced Systemic Resistance in Plants. Singapore: Springer Singapore, 2016. http://dx.doi.org/10.1007/978-981-10-0388-2.
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Tuzun, Sadik, and Elizabeth Bent, eds. Multigenic and Induced Systemic Resistance in Plants. Boston, MA: Springer US, 2006. http://dx.doi.org/10.1007/b101085.
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Strömberg, Anita. Induced systemic resistance in potato to late blight. Uppsala, Sweden: Swedish University of Agricultural Sciences, Dept. of Plant and Forest Protection, Section for Plant Pathology, 1994.
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Varma, Ajit, and Devendra K. Choudhary. Microbial-mediated Induced Systemic Resistance in Plants. Springer, 2018.
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Sadik, Tuzun, and Bent Elizabeth. Multigenic and Induced Systemic Resistance in Plants. Springer London, Limited, 2006.
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Varma, Ajit, and Devendra K. Choudhary. Microbial-mediated Induced Systemic Resistance in Plants. Springer, 2016.
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(Editor), Tuzun Sadik, and Bent Elizabeth (Editor), eds. Multigenic and Induced Systemic Resistance in Plants. Springer, 2005.
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Varma, Ajit, and Devendra K. Choudhary. Microbial-Mediated Induced Systemic Resistance in Plants. Springer London, Limited, 2016.
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Sadik, Tuzun, and Bent Elizabeth. Multigenic and Induced Systemic Resistance in Plants. Springer, 2010.
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Lucena, Carlos, Sabine Dagmar Zimmermann, Ricardo Aroca, and Jianfei Wang, eds. Beneficial Microbes and the Interconnection Between Crop Mineral Nutrition and Induced Systemic Resistance. Frontiers Media SA, 2022. http://dx.doi.org/10.3389/978-2-88974-086-4.
Full textBook chapters on the topic "Induced systemic resistance (ISR)"
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Magotra, Shanu, Deepika Trakroo, Sneha Ganjoo, and Jyoti Vakhlu. "Bacillus-Mediated-Induced Systemic Resistance (ISR) Against Fusarium Corm Rot." In Microbial-mediated Induced Systemic Resistance in Plants, 15–22. Singapore: Springer Singapore, 2016. http://dx.doi.org/10.1007/978-981-10-0388-2_2.
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Annapurna, K., Amod Kumar, L. Vithal Kumar, V. Govindasamy, Pranita Bose, and D. Ramadoss. "PGPR-Induced Systemic Resistance (ISR) in Plant Disease Management." In Bacteria in Agrobiology: Disease Management, 405–25. Berlin, Heidelberg: Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-33639-3_15.
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Pieterse, C. M. J., S. Van Der Ent, J. A. Van Pelt, and L. C. Van Loon. "The role of ethylene in rhizobacteria-induced systemic resistance (ISR)." In Advances in Plant Ethylene Research, 325–31. Dordrecht: Springer Netherlands, 2007. http://dx.doi.org/10.1007/978-1-4020-6014-4_73.
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Kamle, Madhu, Rituraj Borah, Himashree Bora, Amit K. Jaiswal, Ravi Kant Singh, and Pradeep Kumar. "Systemic Acquired Resistance (SAR) and Induced Systemic Resistance (ISR): Role and Mechanism of Action Against Phytopathogens." In Fungal Biology, 457–70. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-41870-0_20.
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Van Loon, L. C. "Systemic Induced Resistance." In Mechanisms of Resistance to Plant Diseases, 521–74. Dordrecht: Springer Netherlands, 2000. http://dx.doi.org/10.1007/978-94-011-3937-3_13.
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Madamanchi, Nageswara Rao, and Joseph Kuć. "Induced Systemic Resistance in Plants." In The Fungal Spore and Disease Initiation in Plants and Animals, 347–62. Boston, MA: Springer US, 1991. http://dx.doi.org/10.1007/978-1-4899-2635-7_16.
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Nadarajah, Kalaivani K. "Induced Systemic Resistance in Rice." In Microbial-mediated Induced Systemic Resistance in Plants, 103–24. Singapore: Springer Singapore, 2016. http://dx.doi.org/10.1007/978-981-10-0388-2_7.
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Kuć, Joseph. "Induced Systemic Resistance — An Overview." In Developments in Plant Pathology, 169–75. Dordrecht: Springer Netherlands, 1995. http://dx.doi.org/10.1007/978-94-015-8420-3_8.
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Binder, Andres, Gianni Baer, Christina Hofmann, and Kati Kováts. "Mechanisms in Systemic Induced Disease Resistance." In NATO ASI Series, 267–72. Berlin, Heidelberg: Springer Berlin Heidelberg, 1989. http://dx.doi.org/10.1007/978-3-642-74158-6_32.
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Kumar, Manoj, Priyanku Teotia, Ajit Varma, Narendra Tuteja, and Vivek Kumar. "Induced Systemic Resistance by Rhizospheric Microbes." In Microbial-mediated Induced Systemic Resistance in Plants, 197–206. Singapore: Springer Singapore, 2016. http://dx.doi.org/10.1007/978-981-10-0388-2_13.
Full textConference papers on the topic "Induced systemic resistance (ISR)"
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"Systemic Acquired Resistance Induced by Some Biotic Agents against Downy Mildew of Cucumber Disease." In International Conference on Plant, Marine and Environmental Sciences. International Institute of Chemical, Biological & Environmental Engineering, 2015. http://dx.doi.org/10.15242/iicbe.c0115022.
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King, A., C. Arnaud, G. Vial, E. Billoir, B. Ozcan, E. Belaidi, C. O'Donnell, and S. Ryan. "The effect of the GLP-1 analogue Liraglutide on intermittent hypoxia-induced systemic insulin resistance in vivo." In ERS International Congress 2022 abstracts. European Respiratory Society, 2022. http://dx.doi.org/10.1183/13993003.congress-2022.2182.
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Zhang, Dayong, Qianjin Yue, Huihui Li, and Yanan Huang. "The Effects on Facilities and Crew Members of the Ice-Resistant Platforms Induced by Ice Vibrations in Bohai Sea." In ASME 2012 31st International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/omae2012-83057.
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The current design and safety assessment of ice-resistance platforms have usually been considered the maximum bearing capacity under the extreme static ice loads. However, the effects on the facilities and crew members induced by the dynamic ice loads are not been considered, and the risks are greater than the structure security. So it is necessary to analyze the effect on the facilities and crew members by ice-induced vibrations. Based on the data monitored on the platforms in the Bohai Sea and the ISO standard about human body in vibration environment, human fatigue on the platforms is evaluated. The typical history curve of the deck acceleration is obtained and used to analyze the excitation of pipelines. A mechanical model of structural vibration of pipeline system is developed. With finite element modeling, the dynamic responses of the pipeline systems induced by deck vibration are calculated. The results show ice-induced vibration may have major effect on the crew members and the facilities, and this failure mode by strongly ice-induced accelerations should be considered in safety producing of the existing platforms and optimization design of the new platforms.
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Liu, Xiang, Yingying Chen, Hai Gu, and Jer-Fang Wu. "A Random Solution to Ice-Induced Vibrations of Conical Structures." In ASME 2015 34th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/omae2015-41696.
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Offshore installations designed to withstand extreme ice actions, such as the multi-leg structures in Cook Inlet, the gravity based Molikpaq during its mobilization in the Beaufort Sea, lighthouses and channel markers in the Baltic Sea, jackets and mooring poles in Bohai Bay and multi-leg structures offshore Sakhalin, have experienced ice-induced vibrations (IIVs). Full-scale data from Bohai Bay also demonstrate that a conical waterline geometry of the structure does reduce the magnitude of the ice forces, but it still experiences IIVs that can be treated as a stochastic process. ISO 19906 recommends that the dynamic ice actions and the corresponding IIVs shall be considered in the design as the fatigue limit state (FLS). ISO 19906 provides the guidance for the time-domain random dynamic ice action on conical structures. The dynamic structural response to such ice action can take the form of a random vibration. As an alternative to the time-domain approach, random vibration analysis can also be done in the frequency domain by the spectral approach. In addition to the time-domain random dynamic ice action on conical structures provided in ISO 19906, a type of ice-force spectrum on conical structures has been developed. In this paper, a simplified single-degree-of-freedom system (SDOF system) and the ice-force spectrum are used to derive an analytical random solution to assess the IIVs of conical structures. As ISO 19906 points out that particular attention shall be given to dynamic actions on narrow structures and flexible structures, the developed random solution can be useful for designers to make a fast estimate of IIVs (i.e., displacement, velocity and acceleration) and to efficiently screen out the key design parameters of a conical ice-resistant structure.
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Delgado, Yamixa, Mallesh Pandrala, Daraishka Perez, Eddian Velazquez, Jaisy Vega, Melissa Milian, and Anamaris Torres. "Abstract 6375: Development of novel Pt-based drugs using Deferasirox as ligand to diminish systemic toxicity and resistance induced by CisPt." In Proceedings: AACR Annual Meeting 2020; April 27-28, 2020 and June 22-24, 2020; Philadelphia, PA. American Association for Cancer Research, 2020. http://dx.doi.org/10.1158/1538-7445.am2020-6375.
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"Bioformulations and Indigenous Plant Protection Measures in Enhancing the Vitalities of Bio-Control Agents for Induced Systemic Resistance Suppressing Asian Soybean Rust in India." In International Conference on Biological, Civil and Environmental Engineering. International Institute of Chemical, Biological & Environmental Engineering, 2014. http://dx.doi.org/10.15242/iicbe.c0314059.
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Schmidt, B., M. R. Buchanan, F. Ofosu, L. A. Brooker, M. Andrew, and McMaster Univ. "ANTITHROMBOTIC PROPERTIES OF HEPARIN IN A NEONATAL MODEL OF THROMBIN INDUCED VENOUS STASIS THROMBOSIS." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643608.
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Anecdotal clinical experience suggests that more heparin is required in newborn infants that in adult patients to effectively treat thrombotic disease. We compared the ability of heparin to inhibit thrombus formation induced by a pathological bolus of thrombin and stasis in newborn piglets and 3 week old pigs. The coagulation system of the newborn piglet closely resembles that of the human neonate Including low antithrombin III (AT-III) activity (0.5U/ml). By 3 weeks, adult porcine values for coagulation factors and inhibitors are reached, while blood volume/kg body weight still approximates that of the newborn piglet. Piglets and pigs were pretreated with saline, 10 or 25U/kg heparin (n ≥16/group/dose. Following an injection of 100U/kg thrombin, systemic 125I-fibrinogen consumption and local 125I-fibrinogen incorporation into jugular venous stasis thrombi were measured. Peak heparin levels were identical In both age groups (Anti-factor Xa assay and protamine sulphate titration). Heparin was less effective in preventing thrombus formation in piglets than in pigs (Table). Heparin was also less effective in preventing systemic neonatal 125I-fibrinogen consumption (p<0.0001 at both heparin doses).Raising AT-III levels to adult values significantly improved the antithrombotic properties of heparin in neonatal piglets. Thrombus formation was completely abolished in 19 or 22 piglets who received a combination of human or porcine AT-III concentrate and 25U/kg heparin. Raising the heparin dose to 50U/kg had the same effect. We conclude that the efficacy of heparin in neutralizing thrombin is decreased in newborn piglets. Treatment with AT-III concentrate overcomes this relative heparin resistance, and may help reduce high heparin doses otherwise required in neonatal thrombotic disease.
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Angelotti, Austin, Rachel Cole, Amy Webb, Maciej Pietrzak, and Martha Belury. "Diet-induced Gene Expression Changes of Cachectic Muscle, Adipose, and Liver." In 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/gvbe2596.
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Cancer cachexia is a systemic disease characterized by muscle and adipose loss that cannot be reversed by increasing caloric intake. Our previous research has shown insulin resistance precedes cancer cachexia in the C26 mouse model of cachexia, and a diet high in linoleic acid, the essential omega-6 polyunsaturated fatty acid, attenuates the C26-induced insulin resistance. Therefore, to better understand how dietary linoleic acid is improving insulin sensitivity, we characterized gene expression changes in three major tissues responsible for controlling insulin sensitivity: skeletal muscle, adipose, and liver. To do this male CD2F1 (Charles River, MA) were randomized to semi-purified diet (24% fat by weight) containing fat prominently from lard, or containing fat prominently from safflower oil (a linoleic acid-rich oil). One week after diet randomization, mice were inoculated with colon-26 (C26) adenocarcinoma cells (1.0E6 cells). 13 days after inoculation mice were euthanized and gastrocnemius skeletal muscle, epididymal white adipose tissue, and liver tissue were collected for total transcriptome analysis using poly-A enriched next generation RNA-sequencing. Differentially expressed genes were selected based on p-values < 0.05. There were no detectable differences in body weight or food intake between the two diets in mice with C26 tumors. Between the two diets 12 genes were differentially expressed in the muscle, while 57 genes were differentially expressed in the liver, and 314 genes were differentially expressed in adipose. A linoleic acid enriched diet had little effect on the skeletal muscle transcriptome but induced larger transcriptome changes in liver and adipose. This could suggest dietary linoleic acid increases insulin sensitivity through affecting metabolism in adipose and liver, rather than skeletal muscle. Determining these diet-induced transcriptome changes allows us to better target tissue-specific molecular mechanisms of linoleic acid in future research.
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Gundersen, Paul, Krassimir Doynov, Torgrim Andersen, and Rune Haakonsen. "Methodology for Determining Remnant Fatigue Life of Flexible Risers Subjected to Slugging and Irregular Waves." In ASME 2012 31st International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/omae2012-83412.
Full textAbstract:
Operational experience has shown that flexible risers producing different combinations of oil, gas and water can be subjected to increased dynamic motions due to slugging — a cyclic accumulation of finite volumes of liquids at a low point of the riser (e.g. sag point of a lazy-S riser) until sufficient pressure is built up behind the slug to push the liquids up through the riser. It has been observed that the slug induced dynamic riser motions can cause riser displacements larger than those generated by moderate and some extreme waves in the absence of slugging. A major impact of the slug induced riser motions is the increased fatigue damage of the tensile wires — the cross-sectional component that most frequently defines the fatigue resistance of flexible riser systems. While international standards like ISO 13628-2 & -11 require and recommend that the effects of slug flow on riser response are considered, they provide no guidance on how to practically incorporate potential slugging effects in pipe design or analysis. A methodology has been developed to determine the remnant fatigue life of a riser subjected to slug induced motions combined with the normally considered vessel motions and wave loading. The methodology is based on using commercially available global and local riser analysis tools. The global analysis tool is used to determine the riser response induced by continuous and regular slug loading combined with loading from different irregular waves, vessel offsets and motions. The slug loading parameters are determined through an iterative process calibrating riser displacements and frequencies with those observed in the field. The local analysis tool is used to determine wire stress transfer functions, which in turn are used to derive wire stress time series from the riser tension and curvature time histories. Stress ranges are identified through rain-flow counting applied on all the calculated stress time series and fatigue performance is estimated using the Palmgren Miner summation of damage using an appropriate wire S-N curve. In a case study, the combined slug and first order wave induced fatigue damage increased by a factor of approximately two compared to the wave induced damage alone. This methodology can be used for: a) riser fitness for service assessments by bounding the impact of slug-induced riser motions observed in the field, and b) new riser design when slugging parameters are adequately bounded by flow assurance calculations.
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Garattini, E., M. Bolis, A. Vallerga, M. Fratelli, G. Paroni, A. Zanetti, M. Kurosaki, M. Gianni', V. Celestini, and M. Terao. "Abstract P5-05-09: Systemic perturbations induced by all-trans retinoic acid in the gene-expression profiles of sixteen breast cancer cell lines characterized by sensitivity and resistance to the anti-proliferative effects of the retinoid." In Abstracts: 2018 San Antonio Breast Cancer Symposium; December 4-8, 2018; San Antonio, Texas. American Association for Cancer Research, 2019. http://dx.doi.org/10.1158/1538-7445.sabcs18-p5-05-09.
Full textReports on the topic "Induced systemic resistance (ISR)"
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Michel Jr., Frederick C., Harry A. J. Hoitink, Yitzhak Hadar, and Dror Minz. Microbial Communities Active in Soil-Induced Systemic Plant Disease Resistance. United States Department of Agriculture, January 2005. http://dx.doi.org/10.32747/2005.7586476.bard.
Full textAbstract:
Induced Systemic Resistance (ISR) is a highly variable property that can be induced by compost amendment of potting media and soils. For example, previous studies showed that only 1 of 79 potting mixes prepared with different batches of mature composts produced from several different types of solid wastes were able to suppress the severity of bacterial leaf spot of radish caused by Xanthomonas campestris pv. armoraciae compared with disease on plants produced in a nonamended sphagnum peat mix. In this project, microbial consortia in the rhizosphere of plants grown in ISR-active compost-amended substrates were characterized. The plants used included primarily cucumber but also tomato and radish. Rhizosphere microbial consortia were characterized using multiple molecular tools including DGGE (Israel) and T -RFLP (Ohio) in both ISR-active field plots and potting media. Universal as well as population-specific bacterial and fungal PCR primers were utilized. T -RFLP analyses using universal bacterial primers showed few significant differences in overall bacterial community composition in ISR-active and inactive substrates (Ohio). In addition, the community members which were significantly different varied when different ISR-activecomposts were used (Ohio). To better characterize the shifts in microbial community structure during the development of ISR, population specific molecular tools were developed (Israel, Ohio).-PCR primers were designed to detect and quantify bacterial groups including Pyrenomycetes, Bacillus, Pan toea, Pseudomonas, Xanthomonas and Streptomyces as well as Trichoderma and Fusarium; two groups of fungi that harbor isolates which are ISR active (Isreal and Ohio). Bacterial consortia associated with cucumber plants grown in compost-amended potting mixtures were shown to be dominated by the phylogenetic taxon Bacteroidetes, including members of the genus Chryseobacterium, which in some cases have been shown to be involved in biocontrol (Israel). Nested-PCR-DGGE analyses coupled with long l6S rDNA sequencing, demonstrated that the Chryseobacteriumspp. detected on seed and the root in compost-amended treatments were derived from the compost itself. The most effective ISR inducing rhizobacterial strains were identified as Bacillus sp. based on partial sequencing of l6S rDNA. However, these strains were significantly less effective in reducing the severity of disease than Trichoderma hamatum382 (T382). A procedure was developed for inoculation of a compost-amended substrate with T -382 which consistently induced ISR in cucumber against Phytophthora blight caused by Phytophthora capsiciand in radish against bacterial spot (Ohio). Inoculation of compost-amended potting mixes with biocontrol agents such as T -382 and other microbes that induce systemic resistance in plants significantly increased the frequency of systemic disease control obtained with natural compost amendments.
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Loebenstein, Gad, William Dawson, and Abed Gera. Association of the IVR Gene with Virus Localization and Resistance. United States Department of Agriculture, August 1995. http://dx.doi.org/10.32747/1995.7604922.bard.
Full textAbstract:
We have reported that localization of TMV in tobacco cultivars with the N gene, is associated with a 23 K protein (IVR) that inhibited replication of several plant viruses. This protein was also found in induced resistant tissue of Nicotiana glutinosa x Nicotiana debneyi. During the present grant we found that TMV production is enhanced in protoplasts and plants of local lesion responding tobacco cultivars exposed to 35oC, parallel to an almost complete suppression of the production of IVR. We also found that IVR is associated with resistance mechanisms in pepper cultivars. We succeeded to clone the IVR gene. In the first attempt we isolated a clone - "101" which had a specific insert of 372 bp (the full length gene for the IVR protein of 23 kD should be around 700 bp). However, attempts to isolate the full length gene did not give clear cut results, and we decided not to continue with this clone. The amino acid sequence of the N-terminus of IVR was determined and an antiserum was prepared against a synthetic peptide representing amino acids residues 1-20 of IVR. Using this antiserum as well as our polyclonal antiserum to IVR a new clone NC-330 was isolated using lamba-ZAP library. This NC-330 clone has an insert of about 1 kB with an open reading frame of 596 bp. This clone had 86.6% homology with the first 15 amino acids of the N-terminal part of IVR and 61.6% homology with the first 23 amino acids of IVR. In the QIA expression system and western blotting of the expressed protein, a clear band of about 21 kD was obtained with IVR antiserum. This clone was used for transformation of Samsun tobacco plants and we have presently plantlets which were rooted on medium containing kanamycin. Hybridization with this clone was also obtained with RNA from induced resistant tissue of Samsun NN but not with RNA from healthy control tissue of Samsun NN, or infected or healthy tissue of Samsun. This further strengthens the previous data that the NC 330 clone codes for IVR. In the U.S. it was shown that IVR is induced in plants containing the N' gene when infected with mutants of TMV that elicit the HR. This is a defined system in which the elicitor is known to be due to permutations of the coat protein which can vary in elicitor strength. The objective was to understand how IVR synthesis is induced after recognition of elicitor coat protein in the signal transduction pathway that leads to HR. We developed systems to manipulate induction of IVR by modifying the elicitor and are using these elicitor molecules to isolate the corresponding plant receptor molecules. A "far-western" procedure was developed that found a protein from N' plants that specifically bind to elicitor coat proteins. This protein is being purified and sequenced. This objective has not been completed and is still in progress. We have reported that localization of TMV in tobacco cultivars with the N gene, is associated with a 23 K protein (IVR) that inhibited replication of several plant viruses. This protein was also found in induced resistant tissue of Nicotiana glutinosa x Nicotiana debneyi.
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Harman, Gary E., and Ilan Chet. Enhancement of plant disease resistance and productivity through use of root symbiotic fungi. United States Department of Agriculture, July 2008. http://dx.doi.org/10.32747/2008.7695588.bard.
Full textAbstract:
The objectives of the project were to (a) compare effects ofT22 and T-203 on growth promotion and induced resistance of maize inbred line Mol7; (b) follow induced resistance of pathogenesis-related proteins through changes in gene expression with a root and foliar pathogen in the presence or absence of T22 or T-203 and (c) to follow changes in the proteome of Mol? over time in roots and leaves in the presence or absence of T22 or T-203. The research built changes in our concepts regarding the effects of Trichoderma on plants; we hypothesized that there would be major changes in the physiology of plants and these would be reflected in changes in the plant proteome as a consequence of root infection by Trichoderma spp. Further, Trichoderma spp. differ in their effects on plants and these changes are largely a consequence of the production of different elicitors of elicitor mixtures that are produced in the zone of communication that is established by root infection by Trichoderma spp. In this work, we demonstrated that both T22 and T-203 increase growth and induce resistance to pathogens in maize. In Israel, it was shown that a hydrophobin is critical for root colonization by Trichoderma strains, and that peptaibols and an expansin-like protein from Ttrichoderma probably act as elicitors of induced resistance in plants. Further, this fungus induces the jasmonate/ethylene pathway of disease resistance and a specific cucumber MAPK is required for transduction of the resistance signal. This is the first such gene known to be induced by fungal systems. In the USA, extensive proteomic analyses of maize demonstrated a number of proteins are differentially regulated by T. harzianum strain T22. The pattern of up-regulation strongly supports the contention that this fungus induces increases in plant disease resistance, respiratory rates and photosynthesis. These are all very consistent with the observations of effects of the fungus on plants in the greenhouse and field. In addition, the chitinolytic complex of maize was examined. The numbers of maize genes encoding these enzymes was increased about 3-fold and their locations on maize chromosomes determined by sequence identification in specific BAC libraries on the web. One of the chitinolytic enzymes was determined to be a heterodimer between a specific exochitinase and different endochitinases dependent upon tissue differences (shoot or root) and the presence or absence of T. harzianum. These heterodimers, which were discovered in this work, are very strongly antifungal, especially the one from shoots in the presence of the biocontrol fungus. Finally, RNA was isolated from plants at Cornell and sent to Israel for transcriptome assessment using Affymetrix chips (the chips became available for maize at the end of the project). The data was sent back to Cornell for bioinformatic analyses and found, in large sense, to be consistent with the proteomic data. The final assessment of this data is just now possible since the full annotation of the sequences in the maize Affy chips is just now available. This work is already being used to discover more effective strains of Trichoderma. It also is expected to elucidate how we may be able to manipulate and breed plants for greater disease resistance, enhanced growth and yield and similar goals. This will be possible since the changes in gene and protein expression that lead to better plant performance can be elucidated by following changes induced by Trichoderma strains. The work was in, some parts, collaborative but in others, most specifically transcriptome analyses, fully synergistic.
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Sessa, Guido, and Gregory Martin. Role of GRAS Transcription Factors in Tomato Disease Resistance and Basal Defense. United States Department of Agriculture, 2005. http://dx.doi.org/10.32747/2005.7696520.bard.
Full textAbstract:
The research problem: Bacterial spot and bacterial speck diseases of tomato are causedby strains of Xanthomonas campestris pv. vesicatoria (Xcv) and Pseudomonas syringae pv.tomato (Pst), respectively. These bacteria colonize aerial parts of the plant and causesignificant losses in tomato production worldwide. Protection against Xcv and Pst bycultural practices or chemical control has been unsuccessful and there are only limitedsources of genetic resistance to these pathogens. In previous research supported in part byBARD IS-3237-01, we extensively characterized changes in tomato gene expression uponthe onset of spot and speck disease resistance. A remarkable finding of these studies wasthe inducibility in tomato leaves by both Xcv and Pst strains of genes encodingtranscriptional activator of the GRAS family, which has not been previously linked todisease resistance. Goals: Central goals of this research were to investigate the role of GRAS genes in tomatoinnate immunity and to assess their potential use for disease control.Specific objectives were to: 1. Identify GRAS genes that are induced in tomato during thedefense response and analyze their role in disease resistance by loss-of-function experiments.2. Overexpress GRAS genes in tomato and characterize plants for possible broad-spectrumresistance. 3. Identify genes whose transcription is regulated by GRAS family. Our main achievements during this research program are in three major areas:1. Identification of tomato GRAS family members induced in defense responses andanalysis of their role in disease resistance. Genes encoding tomato GRAS family memberswere retrieved from databases and analyzed for their inducibility by Pst avirulent bacteria.Real-time RT-PCR analysis revealed that six SlGRAS transcripts are induced during theonset of disease resistance to Pst. Further expression analysis of two selected GRAS genesshowed that they accumulate in tomato plants in response to different avirulent bacteria orto the fungal elicitor EIX. In addition, eight SlGRAS genes, including the Pst-induciblefamily members, were induced by mechanical stress in part in a jasmonic acid-dependentmanner. Remarkably, SlGRAS6 gene was found to be required for tomato resistance to Pstin virus-induced gene silencing (VIGS) experiments.2. Molecular analysis of pathogen-induced GRAS transcriptional activators. In aheterologous yeast system, Pst-inducible GRAS genes were shown to have the ability toactivate transcription in agreement with their putative function of transcription factors. Inaddition, deletion analysis demonstrated that short sequences at the amino-terminus ofSlGRAS2, SlGRAS4 and SlGRAS6 are sufficient for transcriptional activation. Finally,defense-related SlGRAS proteins were found to localize to the cell nucleus. 3. Disease resistance and expression profiles of transgenic plants overexpressing SlGRASgenes. Transgenic plants overexpressing SlGRAS3 or SlGRAS6 were generated. Diseasesusceptibility tests revealed that these plants are not more resistant to Pst than wild-typeplants. Gene expression profiles of the overexpressing plants identified putative direct orindirect target genes regulated by SlGRAS3 and SlGRAS6. Scientific and agricultural significance: Our research activities established a novel linkbetween the GRAS family of transcription factors, plant disease resistance and mechanicalstress response. SlGRAS6 was found to be required for disease resistance to Pstsuggesting that this and possibly other GRAS family members are involved in thetranscriptional reprogramming that takes place during the onset of disease resistance.Their nuclear localization and transcriptional activation ability support their proposed roleas transcription factors or co-activators. However, the potential of utilizing GRAS familymembers for the improvement of plant disease resistance in agriculture has yet to bedemonstrated.
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Avni, Adi, and Kirankumar S. Mysore. Functional Genomics Approach to Identify Signaling Components Involved in Defense Responses Induced by the Ethylene Inducing Xyalanase Elicitor. United States Department of Agriculture, December 2009. http://dx.doi.org/10.32747/2009.7697100.bard.
Full textAbstract:
Plant-microbe interactions involve a large number of global regulatory systems, which are essential for plants to protect themselves against pathogen attack. An ethylene-inducing xylanase (EIX) of Trichoderma viride is a potent elicitor of plant defense responses, like hypersensitive response (HR), in specific cultivars of tobacco (Nicotiana tabacum) and tomato (Lycopersicon esculentum). The central goal of this proposal was to investigate the molecular mechanisms that allow plants to specifically activate defense responses after EIX treatment. We proposed to identify cellular signaling components involved in the induction of HR by the EIX elicitor. The molecular genetic analysis of the signal transduction pathway that modulates hypersensitive responses is an important step in understanding the induction of plant defense responses. The genes that mediate LeEIX2-EIX dependent activation of resistance mechanisms remain to be identified. We used two approaches to identify the cellular signaling components that induce HR mediated by the EIX elicitor. In the first approach, we performed a yeast two-hybrid screening using LeEix2 as bait to identify plant proteins that interact with it. In the second approach, we used virus-induced gene silencing (VIGS) for a high-throughput screen to identify genes that are required for the induction of LeEIX2-EIX mediated HR. VIGS will also be used for functional characterization of genes that will be identified during the yeast two-hybrid screen. This investigation will shed light on cellular processes and signaling components involved in induction of general plant defense against pathogens and will provide the basis for future biotechnological approaches to improve plant resistance to pathogens. Several genes were indentified by the two approaches. We used the VIGS and yeast two hybrid approaches to confirm that activity of the genes initially identified by different procedure. Two genes inhibit the induction of HR by the fungal elicitor in the different systems; Tobacco-Harpin binding protein 1 and cyclopropyl isomerase.
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Fluhr, Robert, and Maor Bar-Peled. Novel Lectin Controls Wound-responses in Arabidopsis. United States Department of Agriculture, January 2012. http://dx.doi.org/10.32747/2012.7697123.bard.
Full textAbstract:
Innate immune responses in animals and plants involve receptors that recognize microbe-associated molecules. In plants, one set of this defense system is characterized by large families of TIR–nucleotide binding site–leucine-rich repeat (TIR-NBS-LRR) resistance genes. The direct interaction between plant proteins harboring the TIR domain with proteins that transmit and facilitate a signaling pathway has yet to be shown. The Arabidopsis genome encodes TIR-domain containing genes that lack NBS and LRR whose functions are unknown. Here we investigated the functional role of such protein, TLW1 (TIR LECTIN WOUNDRESPONSIVE1). The TLW1 gene encodes a protein with two domains: a TIR domain linked to a lectin-containing domain. Our specific aim in this proposal was to examine the ramifications of the TL1-glycan interaction by; A) The functional characterization of TL1 activity in the context of plant wound response and B) Examine the hypothesis that wounding induced specific polysaccharides and examine them as candidates for TL-1 interactive glycan compounds. The Weizmann group showed TLW1 transcripts are rapidly induced by wounding in a JA-independent pathway and T-DNA-tagged tlw1 mutants that lack TLW1 transcripts, fail to initiate the full systemic wound response. Transcriptome methodology analysis was set up and transcriptome analyses indicates a two-fold reduced level of JA-responsive but not JA-independent transcripts. The TIR domain of TLW1 was found to interact directly with the KAT2/PED1 gene product responsible for the final b-oxidation steps in peroxisomal-basedJA biosynthesis. To identify potential binding target(s) of TL1 in plant wound response, the CCRC group first expressed recombinant TL1 in bacterial cells and optimized conditions for the protein expression. TL1 was most highly expressed in ArcticExpress cell line. Different types of extraction buffers and extraction methods were used to prepare plant extracts for TL1 binding assay. Optimized condition for glycan labeling was determined, and 2-aminobenzamide was used to label plant extracts. Sensitivity of MALDI and LC-MS using standard glycans. THAP (2,4,6- Trihydroxyacetophenone) showed minimal background peaks at positive mode of MALDI, however, it was insensitive with a minimum detection level of 100 ng. Using LC-MS, sensitivity was highly increased enough to detect 30 pmol concentration. However, patterns of total glycans displayed no significant difference between different extraction conditions when samples were separated with Dionex ICS-2000 ion chromatography system. Transgenic plants over-expressing lectin domains were generated to obtain active lectin domain in plant cells. Insertion of the overexpression construct into the plant genome was confirmed by antibiotic selection and genomic DNA PCR. However, RT-PCR analysis was not able to detect increased level of the transcripts. Binding ability of azelaic acid to recombinant TL1. Azelaic acid was detected in GST-TL1 elution fraction, however, DHB matrix has the same mass in background signals, which needs to be further tested on other matrices. The major findings showed the importance of TLW1 in regulating wound response. The findings demonstrate completely novel and unexpected TIR domain interactions and reveal a control nexus and mechanism that contributes to the propagation of wound responses in Arabidopsis. The implications are to our understanding of the function of TIR domains and to the notion that early molecular events occur systemically within minutes of a plant sustaining a wound. A WEB site (http://genome.weizmann.ac.il/hormonometer/) was set up that enables scientists to interact with a collated plant hormone database.
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Palukaitis, Peter, Amit Gal-On, Milton Zaitlin, and Victor Gaba. Virus Synergy in Transgenic Plants. United States Department of Agriculture, March 2000. http://dx.doi.org/10.32747/2000.7573074.bard.
Full textAbstract:
Transgenic plants expressing viral genes offer novel means of engendering resistance to those viruses. However, some viruses interact synergistically with other viruses and it is now known that transgenic plants expressing particular genes of one virus may also mediate synergy with a second virus. Thus, our specific objectives were to (1) determine if transgenic plants resistant to one virus showed synergy with another virus; (2) determine what viral sequences were essential for synergy; and (3) determine whether one of more mechanisms were involved i synergy. This project would also enable an evaluation of the risks of synergism associated with the use of such transgenic plants. The conclusion deriving from this project are as follows: - There is more than one mechanism of synergy. - The CMV 2b gene is required for synergistic interactions. - Synergy between a potyvirus and CMV can break natural resistance limiting CMV movement. - Synergy operates at two levels - increase in virus accumulation and increase in pathology - independently of each other. - Various sequences of CMV can interact with the host to alter pathogenicity and affect virus accumulation. - The effect of synergy on CMV satellite RNA accumulatio varies in different systems. - The HC-Pro gene may only function in host plant species to induce synergy. - The HC-Pro is a host range determinant of potyviruses. - Transgenic plants expressing some viral sequences showed synergy with one or more viruses. Transgenic plants expressing CMV RNA 1, PVY NIb and the TMV 30K gene all showed synergy with at least one unrelated virus. - Transgenic plants expressing some viral sequences showed interference with the infection of unrelated viruses. Transgenic plants expressing the TMV 30K, 54K and 126K genes, the PVY NIb gene, or the CMV 3a gene all showed some level of interference with the accumulation (and in some cases the pathology) of unrelated viruses. From our observations, there are agricultural implications to the above conclusions. It is apparent that before they are released commercially, transgenic plants expressing viral sequences for resistance to one virus need to be evaluated fro two properties: - Synergism to unrelated viruses that infect the same plant. Most of these evaluations can be made in the greenhouse, and many can be predicted from the known literature of viruses known to interact with each other. In other cases, where transgenic plants are being generated from new plant species, the main corresponding viruses from the same known interacting genera (e.g., potexviruses and cucumoviruses, potyviruses and cucumoviruses, tobamoviruses and potexviruses, etc.) should be evaluated. - Inhibition or enhancement of other resistance genes. Although it is unlikely that plants to be released would be transformed with HC-Pro or 2b genes, there may be other viral genes that can affect the expression of plant genes encoding resistance to other pathogens. Therefore, transgenic plants expressing viral genes to engender pathogen-derived resistance should be evaluated against a spectrum of other pathogens, to determine whether those resistance activities are still present, have been lost, or have been enhanced!
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Norelli, John L., Moshe Flaishman, Herb Aldwinckle, and David Gidoni. Regulated expression of site-specific DNA recombination for precision genetic engineering of apple. United States Department of Agriculture, March 2005. http://dx.doi.org/10.32747/2005.7587214.bard.
Full textAbstract:
Objectives: The original objectives of this project were to: 1) evaluate inducible promoters for the expression of recombinase in apple (USDA-ARS); 2) develop alternative selectable markers for use in apple to facilitate the positive selection of gene excision by recombinase (Cornell University); 3) compare the activity of three different recombinase systems (Cre/lox, FLP/FRT, and R/RS)in apple using a rapid transient assay (ARO); and 4) evaluate the use of recombinase systems in apple using the best promoters, selectable markers and recombinase systems identified in 1, 2 and 3 above (Collaboratively). Objective 2 was revised from the development alternative selectable markers, to the development of a marker-free selection system for apple. This change in approach was taken due to the inefficiency of the alternative markers initially evaluated in apple, phosphomannose-isomerase and 2-deoxyglucose-6-phosphate phosphatase, and the regulatory advantages of a marker-free system. Objective 3 was revised to focus primarily on the FLP/FRT recombinase system, due to the initial success obtained with this recombinase system. Based upon cooperation between researchers (see Achievements below), research to evaluate the use of the FLP recombinase system under light-inducible expression in apple was then conducted at the ARO (Objective 4). Background: Genomic research and genetic engineering have tremendous potential to enhance crop performance, improve food quality and increase farm profits. However, implementing the knowledge of genomics through genetically engineered fruit crops has many hurdles to be overcome before it can become a reality in the orchard. Among the most important hurdles are consumer concerns regarding the safety of transgenics and the impact this may have on marketing. The goal of this project was to develop plant transformation technologies to mitigate these concerns. Major achievements: Our results indicate activity of the FLP\FRTsite-specific recombination system for the first time in apple, and additionally, we show light- inducible activation of the recombinase in trees. Initial selection of apple transformation events is conducted under dark conditions, and tissue cultures are then moved to light conditions to promote marker excision and plant development. As trees are perennial and - cross-fertilization is not practical, the light-induced FLP-mediated recombination approach shown here provides an alternative to previously reported chemically induced recombinase approaches. In addition, a method was developed to transform apple without the use of herbicide or antibiotic resistance marker genes (marker free). Both light and chemically inducible promoters were developed to allow controlled gene expression in fruit crops. Implications: The research supported by this grant has demonstrated the feasibility of "marker excision" and "marker free" transformation technologies in apple. The use of these safer technologies for the genetic enhancement of apple varieties and rootstocks for various traits will serve to mitigate many of the consumer and environmental concerns facing the commercialization of these improved varieties.
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Wideman, Jr., Robert F., Nicholas B. Anthony, Avigdor Cahaner, Alan Shlosberg, Michel Bellaiche, and William B. Roush. Integrated Approach to Evaluating Inherited Predictors of Resistance to Pulmonary Hypertension Syndrome (Ascites) in Fast Growing Broiler Chickens. United States Department of Agriculture, December 2000. http://dx.doi.org/10.32747/2000.7575287.bard.
Full textAbstract:
Background PHS (pulmonary hypertension syndrome, ascites syndrome) is a serious cause of loss in the broiler industry, and is a prime example of an undesirable side effect of successful genetic development that may be deleteriously manifested by factors in the environment of growing broilers. Basically, continuous and pinpointed selection for rapid growth in broilers has led to higher oxygen demand and consequently to more frequent manifestation of an inherent potential cardiopulmonary incapability to sufficiently oxygenate the arterial blood. The multifaceted causes and modifiers of PHS make research into finding solutions to the syndrome a complex and multi threaded challenge. This research used several directions to better understand the development of PHS and to probe possible means of achieving a goal of monitoring and increasing resistance to the syndrome. Research Objectives (1) To evaluate the growth dynamics of individuals within breeding stocks and their correlation with individual susceptibility or resistance to PHS; (2) To compile data on diagnostic indices found in this work to be predictive for PHS, during exposure to experimental protocols known to trigger PHS; (3) To conduct detailed physiological evaluations of cardiopulmonary function in broilers; (4) To compile data on growth dynamics and other diagnostic indices in existing lines selected for susceptibility or resistance to PHS; (5) To integrate growth dynamics and other diagnostic data within appropriate statistical procedures to provide geneticists with predictive indices that characterize resistance or susceptibility to PHS. Revisions In the first year, the US team acquired the costly Peckode weigh platform / individual bird I.D. system that was to provide the continuous (several times each day), automated weighing of birds, for a comprehensive monitoring of growth dynamics. However, data generated were found to be inaccurate and irreproducible, so making its use implausible. Henceforth, weighing was manual, this highly labor intensive work precluding some of the original objectives of using such a strategy of growth dynamics in selection procedures involving thousands of birds. Major conclusions, solutions, achievements 1. Healthy broilers were found to have greater oscillations in growth velocity and acceleration than PHS susceptible birds. This proved the scientific validity of our original hypothesis that such differences occur. 2. Growth rate in the first week is higher in PHS-susceptible than in PHS-resistant chicks. Artificial neural network accurately distinguished differences between the two groups based on growth patterns in this period. 3. In the US, the unilateral pulmonary occlusion technique was used in collaboration with a major broiler breeding company to create a commercial broiler line that is highly resistant to PHS induced by fast growth and low ambient temperatures. 4. In Israel, lines were obtained by genetic selection on PHS mortality after cold exposure in a dam-line population comprising of 85 sire families. The wide range of PHS incidence per family (0-50%), high heritability (about 0.6), and the results in cold challenged progeny, suggested a highly effective and relatively easy means for selection for PHS resistance 5. The best minimally-invasive diagnostic indices for prediction of PHS resistance were found to be oximetry, hematocrit values, heart rate and electrocardiographic (ECG) lead II waves. Some differences in results were found between the US and Israeli teams, probably reflecting genetic differences in the broiler strains used in the two countries. For instance the US team found the S wave amplitude to predict PHS susceptibility well, whereas the Israeli team found the P wave amplitude to be a better valid predictor. 6. Comprehensive physiological studies further increased knowledge on the development of PHS cardiopulmonary characteristics of pre-ascitic birds, pulmonary arterial wedge pressures, hypotension/kidney response, pulmonary hemodynamic responses to vasoactive mediators were all examined in depth. Implications, scientific and agricultural Substantial progress has been made in understanding the genetic and environmental factors involved in PHS, and their interaction. The two teams each successfully developed different selection programs, by surgical means and by divergent selection under cold challenge. Monitoring of the progress and success of the programs was done be using the in-depth estimations that this research engendered on the reliability and value of non-invasive predictive parameters. These findings helped corroborate the validity of practical means to improve PHT resistance by research-based programs of selection.
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Aly, Radi, and John I. Yoder. Development of resistant crop plants to parasitic weeds based on trans-specific gene silencing. United States Department of Agriculture, January 2013. http://dx.doi.org/10.32747/2013.7598146.bard.
Full textAbstract:
Broomrapes (Orobanche/Phelipanchespp.) are holo parasitic plants that subsist on the roots of a variety of agricultural crops and cause severe losses to the yield quality and quantity. Effective methods for controlling parasitic weeds are scarce, with only a few known cases of genetic resistance. In the current study, we proposed an improved strategy for the control of parasitic weeds based on trans-specific gene-silencing of three parasite genes at once. We used two strategies to express dsRNA containing selected sequences of three Phelipancheaegyptiacagenes PaACS, PaM6PR and PaPrx1 (pma): transient expression using Tobacco rattle virus (TRV:pma) as a virus-induced gene-silencing (VIGS) vector and stable expression in transgenic tomato Solanumlycopersicum(Mill.) plants harboring a hairpin construct (pBINPLUS35:pma). siRNA-mediated transgene-silencing (20–24 nt) was detected in the host plants. Our results demonstrate that the quantities of PaACSand PaM6PR transcripts from P. aegyptiacatubercles grown on transgenic tomato or on Tobacco rattle virus-infected Nicotianabenthamianaplants were significantly reduced. However, only partial reductions in the quantity of PaPrx1 transcripts were observed in the parasite tubercles grown on tomato and on N. benthamianaplants. Concomitant with the suppression of the target genes, there were significant decreases in the number and weight of the parasite tubercles that grew on the host plants, in both the transient and the stable experimental systems. The results of the work carried out using both strategies point to the movement of mobile exogenous siRNA from the host to the parasite, leading to the impaired expression of essential parasite target genes. In light of the importance of parasitic weeds to world agriculture and the difficulty of obtaining resistance by conventional methods, we assume that genetic resistance based on the silencing of key metabolic genes in the parasite is now feasible. BARD Report - Project4622 Page 2 of 60