Articles de revues : « Mlo genes »

1

Shi, Jianlei, Hongjian Wan, Wenshan Zai, Zili Xiong et Weiren Wu. « Phylogenetic Relationship of Plant MLO Genes and Transcriptional Response of MLO Genes to Ralstonia solanacearum in Tomato ». Genes 11, n^o 5 (29 avril 2020) : 487. http://dx.doi.org/10.3390/genes11050487.

Texte intégral

Résumé :

As a broad-spectrum disease resistance factor, MLO is involved in a variety of biotic and abiotic stress responses in plants. To figure out the structural features, phylogenetic relationships, and expression patterns of MLO genes, we investigated the genome and transcriptome sequencing data of 28 plant species using bioinformatics tools. A total of 197 MLO genes were identified. They possessed 5–7 transmembrane domains, but only partially contained a calmodulin-binding domain. A total of 359 polymorphic sites and 142 haplotypes were found in 143 sequences, indicating the rich nucleotide diversity of MLO genes. The MLO genes were unevenly distributed on chromosomes or scaffolds and were mainly located at the ends, forming clusters (24.1% genes), tandem duplicates (5.7%), and segment duplicates (36.2%). The MLO genes could be classified into three groups by phylogenetic analysis. The angiosperm genes were mainly in subgroup IA, Selaginella moellendorffii genes were in subgroup IA and IIIB, Physcomitrella patens genes were in subgroup IB and IIIA, and almost all algae genes were in group II. About half of the MLO genes had homologs within and across species. The Ka/Ks values were all less than 1, varying 0.01–0.78, suggesting that purifying selection had occurred in MLO gene evolution. In tomato, RNA-seq data indicated that SlMLO genes were highly expressed in roots, followed by flowers, buds, and leaves, and also regulated by different biotic stresses. qRT–PCR analysis revealed that SlMLO genes could respond to tomato bacterial wilt, with SlMLO1, SlMLO2, SlMLO4, and SlMLO6 probably involved in the susceptibility response, whereas SlMLO14 and SlMLO16 being the opposite. These results lay a foundation for the isolation and application of related genes in plant disease resistance breeding.

Styles APA, Harvard, Vancouver, ISO, etc.

2

KEMAL, RAHMAT AZHARI, ERIC BERNARDUS L. SANDJAJA, AUDI PUTRA SANTOSA et JEREMIAS IVAN. « Short Communication : Identification of Mildew Locus O (MLO) genes in Durio zibethinus genome corresponding with the Powdery Mildew disease ». Biodiversitas Journal of Biological Diversity 19, n^o 6 (9 octobre 2018) : 2204–12. http://dx.doi.org/10.13057/biodiv/d190628.

Texte intégral

Résumé :

Kemal RA, Sandjaja EBL, Santosa AP, Ivan J. 2018. Short Communication: Identification of Mildew Locus O (MLO) genes in Durio zibethinus genome corresponding with the Powdery Mildew disease. Biodiversitas 19: 2204-2212. Mildew Locus O (MLO) is a protein consisting of seven transmembrane domains and appears in the various type of plants. MLO proteins are classified into seven clades. It is known that specific clades have different roles in a plant. MLOs from Clades IV and V have been linked to plant's susceptibility to Powdery Mildew (PM) disease. This study aimed to provide an overview of MLO genes present in durian (Durio zibethinus) genome. Bioinformatic analyses were conducted to analyze the phylogeny and structure of MLO genes and proteins in durian. The result showed that there were 20 putative DzMLO genes in durian, encoding 39 putative DzMLO proteins. Durian MLOs belong to Clade I-VI with one protein belongs to Clade IV and five proteins belong to Clade V. Those six MLO proteins shared a common motif in C-terminal and second intracellular domains. Putative alternative splicing and differential expressions were observed among Clade V DzMLO genes. These findings will facilitate the functional characterization of MLO genes and proteins in durian. Functional studies, especially on C-terminal and second intracellular domains, need to be conducted to elucidate the role of MLO in PM susceptibility in durian.

Styles APA, Harvard, Vancouver, ISO, etc.

3

Ge, Cynthia, Paula Moolhuijzen, Lee Hickey, Elzette Wentzel, Weiwei Deng, Eric G. Dinglasan et Simon R. Ellwood. « Physiological Changes in Barley mlo-11 Powdery Mildew Resistance Conditioned by Tandem Repeat Copy Number ». International Journal of Molecular Sciences 21, n^o 22 (20 novembre 2020) : 8769. http://dx.doi.org/10.3390/ijms21228769.

Texte intégral

Résumé :

Wild barley accessions have evolved broad-spectrum defence against barley powdery mildew through recessive mlo mutations. However, the mlo defence response is associated with deleterious phenotypes with a cost to yield and fertility, with implications for natural fitness and agricultural productivity. This research elucidates the mechanism behind a novel mlo allele, designated mlo-11(cnv2), which has a milder phenotype compared to standard mlo-11. Bisulphite sequencing and histone ChIP-seq analyses using near-isogenic lines showed pronounced repression of the Mlo promoter in standard mlo-11 compared to mlo-11(cnv2), with repression governed by 24 nt heterochromatic small interfering RNAs. The mlo-11(cnv2) allele appears to largely reduce the physiological effects of mlo while still endorsing a high level of powdery mildew resistance. RNA sequencing showed that this is achieved through only partly restricted expression of Mlo, allowing adequate temporal induction of defence genes during infection and expression close to wild-type Mlo levels in the absence of infection. The two mlo-11 alleles showed copy number proportionate oxidase and peroxidase expression levels during infection, but lower amino acid and aromatic compound biosynthesis compared to the null allele mlo-5. Examination of highly expressed genes revealed a common WRKY W-box binding motif (consensus ACCCGGGACTAAAGG) and a transcription factor more highly expressed in mlo-11 resistance. In conclusion, mlo-11(cnv2) appears to significantly mitigate the trade-off between mlo defence and normal gene expression.

Styles APA, Harvard, Vancouver, ISO, etc.

4

Fang, Peihong, Paul Arens, Xintong Liu, Xin Zhang, Deepika Lakwani, Fabrice Foucher, Jérémy Clotault et al. « Analysis of allelic variants of RhMLO genes in rose and functional studies on susceptibility to powdery mildew related to clade V homologs ». Theoretical and Applied Genetics 134, n^o 8 (2 mai 2021) : 2495–515. http://dx.doi.org/10.1007/s00122-021-03838-7.

Texte intégral

Résumé :

Abstract Key message Rose has 19 MLO genes. Of these, RhMLO1 and RhMLO2 were shown to be required for powdery mildew infection, which suggests their potential as susceptibility targets towards disease resistance. Abstract Powdery mildew, caused by Podosphaera pannosa, is one of the most serious and widespread fungal diseases for roses, especially in greenhouse-grown cut roses. It has been shown that certain MLO genes are involved in powdery mildew susceptibility and that loss of function in these genes in various crops leads to broad-spectrum, long-lasting resistance against this fungal disease. For this reason, these MLO genes are called susceptibility genes. We carried out a genome-wide identification of the MLO gene family in the Rosa chinensis genome, and screened for allelic variants among 22 accessions from seven different Rosa species using re-sequencing and transcriptome data. We identified 19 MLO genes in rose, of which four are candidate genes for functional homologs in clade V, which is the clade containing all dicot MLO susceptibility genes. We detected a total of 198 different allelic variants in the set of Rosa species and accessions, corresponding to 5–15 different alleles for each of the genes. Some diploid Rosa species shared alleles with tetraploid rose cultivars, consistent with the notion that diploid species have contributed to the formation of tetraploid roses. Among the four RhMLO genes in clade V, we demonstrated using expression study, virus-induced gene silencing as well as transient RNAi silencing that two of them, RhMLO1 and RhMLO2, are required for infection by P. pannosa and suggest their potential as susceptibility targets for powdery mildew resistance breeding in rose.

Styles APA, Harvard, Vancouver, ISO, etc.

5

Yaeno, Takashi, Miki Wahara, Mai Nagano, Hikaru Wanezaki, Hirotaka Toda, Hiroshi Inoue, Ayaka Eishima et al. « RACE1, a Japanese Blumeria graminis f. sp. hordei isolate, is capable of overcoming partially mlo-mediated penetration resistance in barley in an allele-specific manner ». PLOS ONE 16, n^o 8 (23 août 2021) : e0256574. http://dx.doi.org/10.1371/journal.pone.0256574.

Texte intégral

Résumé :

Loss-of-function mutation of the MILDEW RESISTANCE LOCUS O (Mlo) gene confers durable and broad-spectrum resistance to powdery mildew fungi in various plants, including barley. In combination with the intracellular nucleotide-binding domain and leucine-rich repeat receptor (NLR) genes, which confer the race-specific resistance, the mlo alleles have long been used in barley breeding as genetic resources that confer robust non-race-specific resistance. However, a Japanese Blumeria graminis f. sp. hordei isolate, RACE1, has been reported to have the potential to overcome partially the mlo-mediated penetration resistance, although this is yet uncertain because the putative effects of NLR genes in the tested accessions have not been ruled out. In this study, we examined the reproducibility of the earlier report and found that the infectious ability of RACE1, which partially overcomes the mlo-mediated resistance, is only exerted in the absence of NLR genes recognizing RACE1. Furthermore, using the transient-induced gene silencing technique, we demonstrated that RACE1 can partially overcome the resistance in the host cells with suppressed MLO expression but not in plants possessing the null mutant allele mlo-5.

Styles APA, Harvard, Vancouver, ISO, etc.

6

Jambagi, Shridhar, Shridhar Jambagi, Jim M. Dunwell et Jim M. Dunwell. « Identification and Expression Analysis of Fragaria Vesca MLO Genes Involved in Interaction with Powdery Mildew (Podosphaera Aphanis) ». Journal of Advances in Plant Biology 1, n^o 1 (22 novembre 2017) : 40–54. http://dx.doi.org/10.14302/issn.2638-4469.japb-17-1838.

Texte intégral

Résumé :

Strawberry powdery mildew, caused by Podosphaeraaphanis is a major fungal disease that affects strawberry yield and quality. In the model plant species Arabidopsis and the crop plants barley, tomato and pea, the Mildew resistance locus O (MLO) proteins have been found to be required for powdery mildew susceptibility. The present study, based on the sequence of a wild plum (Prunus americana) MLO protein, identified 16 MLO genes within the genome of woodland strawberry, Fragaria vesca and examined their expression pattern in response to powdery mildew infection in three diploid strawberry cultivars. Phylogenetic analysis showed that the FvMLO genes can be classified into six clades. Four FvMLO genes were grouped into clade III, which comprises MLO genes from Arabidopsis, tomato and grapevine that mediate powdery mildew susceptibility. A RNA-seq analysis of two diploid strawberry cultivars, F. vescassp. vesca accession Hawaii 4 (HW) and F. vesca f. semperflorens line “Yellow Wonder 5AF7” (YW) at 1 d (1 DAI) and 8 d (8 DAI) after infection showed the expression of 12 out of the 16 FvMLO genes. The comparison of Fragments Per Kilobase of transcript per Million mapped reads (FPKM values) detected by RNA-seq and expression values of qRT-PCR for FvMLO genes showed substantial agreement. The FvMLO3 gene, which was grouped in clade III and orthologous to the Arabidopsis,tomato and grapevine genes, was highly expressed in YW compared to other FvMLO genes across varieties. The results showed that FvMLO genes can be used as potential candidates to engineer powdery mildew resistance in strawberry based on MLO suppression or genome editing.

Styles APA, Harvard, Vancouver, ISO, etc.

7

Baykal, Ulku, et Kadriye Özcan. « Analysis of Clade V MLO Gene Expressions in Hazelnut Leaves upon Exposure to Powdery Mildew ». Turkish Journal of Agriculture - Food Science and Technology 10, n^o 4 (4 mai 2022) : 595–612. http://dx.doi.org/10.24925/turjaf.v10i4.595-612.4686.

Texte intégral

Résumé :

Powdery mildew affecting European hazelnut Corylus avellana L. trees in Turkey is caused by the obligate biotrophic fungus Erysiphe corylacearum. This fungal disease causes significant economic losses by reducing the yield and quality of hazelnuts. Loss-of-function mutations in the mildew resistance locus o (MLO) gene family of many plants confer high levels of broad-spectrum resistance to powdery mildew. The proteins encoded by the genes at the MLO locus are divided into approximately seven different conserved clades. Among them, the phylogenetic clade V has been shown to be involved in PM susceptibility, as inactivation of these genes leads to long-term disease resistance in dicotyledons. In this study, we examined the temporal expression pattern of three hazelnut MLO genes, previously identified as clade V, in response to powdery mildew infection in C. avellana cv. Tombul. Leaves are the main tissue affected by the powdery mildew pathogen in hazelnut plants. Analysis of MLO expression in hazelnut leaves showed that CavMLO2 and CavMLO6 were significantly upregulated after challenge with E. corylacearum, providing preliminary evidence that they may be involved in PM susceptibility. Thus, these results present a basis for the isolation and use of relevant genes in plant breeding for disease resistance. Moreover, expression profiles of the clade V MLO genes are also important to identify candidate genes that need to be silenced or edited for future molecular studies to obtain resistant hazelnut varieties.

Styles APA, Harvard, Vancouver, ISO, etc.

8

Saja, Diana, Anna Janeczko, Balázs Barna, Andrzej Skoczowski, Michał Dziurka, Andrzej Kornaś et Gábor Gullner. « Powdery Mildew-Induced Hormonal and Photosynthetic Changes in Barley Near Isogenic Lines Carrying Various Resistant Genes ». International Journal of Molecular Sciences 21, n^o 12 (25 juin 2020) : 4536. http://dx.doi.org/10.3390/ijms21124536.

Texte intégral

Résumé :

The present work focused on the characterization of some physiological mechanisms activated upon powdery mildew inoculation of the susceptible barley cultivar Ingrid and its near-isogenic lines (NILs) carrying various resistant genes (Mla, Mlg and mlo). After inoculation with Blumeria graminis f. sp. hordei (Bgh), measurements of leaf reflectance and chlorophyll a fluorescence were performed 3 and 7 day post-inoculation (dpi), while hormone assays were made 7 dpi. Bgh-inoculated resistant genotypes were characterized by lowered leaf reflectance parameters that correlated with carotenoids (CRI) and water content (WBI) in comparison to inoculated Ingrid. The PSII activity (i.e., Fv/Fm, ETo/CSm and P.I.ABS) strongly decreased in susceptible Ingrid leaves when the disease symptoms became visible 7 dpi. In Mla plants with visible hypersensitive spots the PSII activity decreased to a lesser extent. Inoculation resulted in a very slight decrease of photosynthesis at later stage of infection in Mlg plants, whereas in resistant mlo plants the PSII activity did not change. Chlorophyll a fluorescence measurements allowed presymptomatic detection of infection in Ingrid and Mla. Changes in the homeostasis of 22 phytohormones (cytokinins, auxins, gibberellins and the stress hormones JA, SA and ABA) in powdery mildew inoculated barley are discussed in relation to resistance against this biotrophic pathogen.

Styles APA, Harvard, Vancouver, ISO, etc.

9

Jarosch, Birgit, Karl-Heinz Kogel et Ulrich Schaffrath. « The Ambivalence of the Barley Mlo Locus : Mutations Conferring Resistance Against Powdery Mildew (Blumeria graminis f. sp. hordei) Enhance Susceptibility to the Rice Blast Fungus Magnaporthe grisea ». Molecular Plant-Microbe Interactions® 12, n^o 6 (juin 1999) : 508–14. http://dx.doi.org/10.1094/mpmi.1999.12.6.508.

Texte intégral

Résumé :

Recessive alleles of the barley Mlo locus confer non-race-specific resistance against the powdery mildew fungus Blumeria graminis f. sp. hordei (Bgh). Recently the Mlo gene has been isolated and it was suggested that the Mlo product is a negative regulator of cell death. Thus, loss of function can precondition cells to a higher responsiveness for the onset of multiple defense functions. Here, we document an enhanced susceptibility of barley mlo mutants to the rice blast fungus Magnaporthe grisea. The disease phenotype is independent of the barley cultivar in which the mlo allele has been introgressed and occurs in equal amounts in barley backcross lines of cv. Ingrid carrying the mlo-1, mlo-3, or mlo-5 allele. Ror genes, which are required for the full expression of mlo resistance in barley against Bgh, do not affect the specific mlo-mediated phenotype observed after M. grisea infection. Formation of an effective papilla restricts blast development in epidermal cells of Mlo plants. In contrast, papillae are mostly penetrated in mlo mutants and, as a consequence, the fungus spreads into adjacent mesophyll cells. Both wild-type plants and mlo mutants did not differ in perception of a purified elicitor derived from M. grisea. Thus, we hypothesize that a functional Mlo protein is a prerequisite for penetration resistance of barley to fungal pathogens like M. grisea. The benefit of mlo alleles for durable resistance in barley and a proposed role of mlo-type-mutations in rice are discussed.

Styles APA, Harvard, Vancouver, ISO, etc.

10

Panstruga, R. « Serpentine plant MLO proteins as entry portals for powdery mildew fungi ». Biochemical Society Transactions 33, n^o 2 (1 avril 2005) : 389–92. http://dx.doi.org/10.1042/bst0330389.

Texte intégral

Résumé :

In the dicotyledonous plant species Arabidopsis and the monocot barley, presence of specific isoforms of the family of heptahelical plasma membrane-localized MLO proteins is required for successful host-cell invasion by ascomycete powdery mildew fungi. Absence of these MLO proteins, either caused by natural polymorphisms or induced lesions in the respective Mlo genes, results in failure of fungal sporelings to penetrate the plant cell wall. As a consequence, recessively inherited cell-autonomous mlo resistance is effective against all known isolates of powdery mildew fungi colonizing either barley or Arabidopsis. Barley MLO interacts constitutively with the cytoplasmic calcium sensor calmodulin, but the strength of this interaction increases transiently during fungal pathogenesis. In addition, MLO as well as ROR2, a plasma membrane-resident syntaxin also implicated in mlo penetration resistance, focally accumulate at sites of attempted fungal attack, thereby defining a novel pathogen-triggered micro-domain. In conclusion, powdery mildew fungi appear to specifically corrupt MLO to modulate vesicle-associated processes at the plant cell periphery for successful pathogenesis.

Styles APA, Harvard, Vancouver, ISO, etc.

11

Kusch, Stefan, et Ralph Panstruga. « mlo-Based Resistance : An Apparently Universal “Weapon” to Defeat Powdery Mildew Disease ». Molecular Plant-Microbe Interactions® 30, n^o 3 (mars 2017) : 179–89. http://dx.doi.org/10.1094/mpmi-12-16-0255-cr.

Texte intégral

Résumé :

Loss-of-function mutations of one or more of the appropriate Mildew resistance locus o (Mlo) genes are an apparently reliable “weapon” to protect plants from infection by powdery mildew fungi, as they confer durable broad-spectrum resistance. Originally detected as a natural mutation in an Ethiopian barley landrace, this so-called mlo-based resistance has been successfully employed in European barley agriculture for nearly four decades. More recently, mlo-mediated resistance was discovered to be inducible in virtually every plant species of economic or scientific relevance. By now, mlo resistance has been found (as natural mutants) or generated (by induced mutagenesis, gene silencing, and targeted or nontargeted gene knock-out) in a broad range of monocotyledonous and dicotyledonous plant species. Here, we review features of mlo resistance in barley, discuss approaches to identify the appropriate Mlo gene targets to induce mlo-based resistance, and consider the issue of pleiotropic effects often associated with mlo-mediated immunity, which can harm plant yield and quality. We portray mlo-based resistance as an apparently universal and effective weapon to defeat powdery mildew disease in a multitude of plant species.

Styles APA, Harvard, Vancouver, ISO, etc.

12

Dreiseitl, Antonín, et Gregory Platz. « Powdery mildew resistance genes in barley varieties grown in Australia ». Crop and Pasture Science 63, n^o 10 (2012) : 997. http://dx.doi.org/10.1071/cp12165.

Texte intégral

Résumé :

Barley (Hordeum vulgare L.) is a major crop in Australia and powdery mildew (Blumeria graminis f. sp. hordei) is one of its most common diseases. Genes for resistance to powdery mildew were postulated for 86 Australian barley varieties and nine advanced breeding lines using 40 reference isolates of the pathogen. Fifty isolates collected in Australia in 2011 were used for additional tests of some varieties. In total, 22 known resistance genes [mlo, Mla1, MlaAl2, Mla3, Mla6, Mla7, Mla8, Mla9, Mla12, Mla13, Mlat, Mlg, MlGa, Mlk1, MlLa, Mlra, Ml(Ab), Ml(Ch), Ml(Dr2), Ml(He2), Ml(Lo) and Ml(St)] were detected. The most frequent genes were Mla8 and Mlg present in 43 and 34 varieties, respectively, while MlGa was found in 12 varieties. Each of the specific resistance genes Mla1, Mla3, Mla6, Mla9, Mla13, Ml(St) and the non-specific recessive gene mlo was found in one variety only. The varieties Maritime and Stirling appear to carry no specific resistance genes. Fifteen unknown resistances were detected. It is recommended that Australian barley breeding programs exploit European varieties possessing mlo to improve the resistance to powdery mildew in new varieties.

Styles APA, Harvard, Vancouver, ISO, etc.

13

Qiu, Xianqin, Hongying Jian, Qigang Wang, Kaixue Tang et Manzhu Bao. « Expression Pattern Analysis of Four Mlo Genes from Rose ». Journal of the American Society for Horticultural Science 140, n^o 4 (juillet 2015) : 333–38. http://dx.doi.org/10.21273/jashs.140.4.333.

Texte intégral

Résumé :

Rose (Rosa hybrida) is one of the most economically important ornamentals worldwide. Powdery mildew (Podosphaera pannosa) is a major disease in cut and potted roses. In dicots such as arabidopsis (Arabidopsis thaliana), pea (Pisum sativum), and tomato (Solanum lycopersicum), loss-of-function mutations in mildew resistance locus o (Mlo) genes confer high levels of broad-spectrum resistance to powdery mildew. Here, we present spatiotemporal expression patterns of four Mlo genes from R. hybrida based on real-time fluorescence quantitative polymerase chain reaction (qPCR). Phylogenetically closely related R. hybrida mildew resistance locus o (RhMLO) genes showed similar or overlapping tissue specificity and analogous responsiveness to external stimuli. RhMLO1 and RhMLO2 transcriptional levels were upregulated more than 2-fold by external stimuli, especially by inoculation with powdery mildew fungus P. pannosa at early time points. This phenomenon was not found for RhMLO3 or RhMLO4. The results indicated that RhMLO1 and RhMLO2 might play important roles in rose–powdery mildew pathogen interactions. Our findings may provide useful information for the study of mechanisms of powdery mildew susceptibility in rose.

Styles APA, Harvard, Vancouver, ISO, etc.

14

Hofer, Katharina, Andrea Linkmeyer, Katharina Textor, Ralph Hückelhoven et Michael Hess. « MILDEW LOCUS O Mutation Does Not Affect Resistance to Grain Infections with Fusarium spp. and Ramularia collo-cygni ». Phytopathology® 105, n^o 9 (septembre 2015) : 1214–19. http://dx.doi.org/10.1094/phyto-12-14-0381-r.

Texte intégral

Résumé :

MILDEW LOCUS O defines a major susceptibility gene for powdery mildew, and recessive mlo resistance alleles are widely used in breeding for powdery mildew resistance in spring barley. Barley powdery mildew resistance, which is conferred by mlo genes, is considered to be costly in terms of spontaneous defense reactions and enhanced susceptibility to cell-death-inducing pathogens. We assessed fungal infestation of barley (Hordeum vulgare) grain by measuring fungal DNA after natural infection with Fusarium spp. and Ramularia collo-cygni or after inoculation with Fusarium spp. in the field. Powdery-mildew-resistant mlo5 genotypes did not show enhanced Fusarium spp. or R. collo-cygni DNA content of grain over four consecutive years. Data add to our understanding of pleiotropic effects of mlo-mediated powdery mildew resistance and contributes to the discussion of whether or not application of barley mlo mutations may support pathogenesis of cell-death-inducing fungal pathogens under field conditions.

Styles APA, Harvard, Vancouver, ISO, etc.

15

Inukai, Tsuyoshi, M. Isabel Vales, Kiyosumi Hori, Kazuhiro Sato et Patrick M. Hayes. « RMo1 Confers Blast Resistance in Barley and Is Located within the Complex of Resistance Genes Containing Mla, a Powdery Mildew Resistance Gene ». Molecular Plant-Microbe Interactions® 19, n^o 9 (septembre 2006) : 1034–41. http://dx.doi.org/10.1094/mpmi-19-1034.

Texte intégral

Résumé :

Isolates of Magnaporthe oryzae (the causal agent of rice blast disease) can infect a range of grass species, including barley. We report that barley Hordeum vulgare cv. Baronesse and an experimental line, BCD47, show a range of resistance reactions to infection with two rice blast isolates. The complete resistance of Baronesse to the isolate Ken 54–20 is controlled by a single dominant gene, designated RMo1. RMo1 mapped to the same linkage map position on chromosome 1H as the powdery mildew resistance locus Mla and an expressed sequence tag (k04320) that corresponds to the barley gene 711N16.16. A resistance quantitative trait locus (QTL), at which Baronesse contributed the resistance allele, to the isolate Ken 53–33 also mapped at the same position as RMo1. Synteny analysis revealed that a corresponding region on rice chromosome 5 includes the bacterial blight resistance gene xa5. These results indicate that a defined region on the short arm of barley chromosome 1H, including RMo1 and Mla, harbors genes conferring qualitative and quantitative resistance to multiple pathogens. The partial resistance of BCD47 to Ken53–33 is determined by alleles at three QTL, two of which coincide with the linkage map positions of the mildew resistance genes mlo and Mlf.

Styles APA, Harvard, Vancouver, ISO, etc.

16

Wu, Hongpo, Weiwei Zhang, Martin Schuster, Marcin Moch, Reinhard Windoffer, Gero Steinberg, Christopher J. Staiger et Ralph Panstruga. « Alloxan Disintegrates the Plant Cytoskeleton and Suppresses mlo-Mediated Powdery Mildew Resistance ». Plant and Cell Physiology 61, n^o 3 (18 novembre 2019) : 505–18. http://dx.doi.org/10.1093/pcp/pcz216.

Texte intégral

Résumé :

Abstract Recessively inherited mutant alleles of Mlo genes (mlo) confer broad-spectrum penetration resistance to powdery mildew pathogens in angiosperm plants. Although a few components are known to be required for mlo resistance, the detailed molecular mechanism underlying this type of immunity remains elusive. In this study, we identified alloxan (5,5-dihydroxyl pyrimidine-2,4,6-trione) and some of its structural analogs as chemical suppressors of mlo-mediated resistance in monocotyledonous barley (Hordeum vulgare) and dicotyledonous Arabidopsis thaliana. Apart from mlo resistance, alloxan impairs nonhost resistance in Arabidopsis. Histological analysis revealed that the chemical reduces callose deposition and hydrogen peroxide accumulation at attempted fungal penetration sites. Fluorescence microscopy revealed that alloxan interferes with the motility of cellular organelles (peroxisomes, endosomes and the endoplasmic reticulum) and the pathogen-triggered redistribution of the PEN1/SYP121 t-SNARE protein. These cellular defects are likely the consequence of disassembly of actin filaments and microtubules upon alloxan treatment. Similar to the situation in animal cells, alloxan elicited the temporary accumulation of reactive oxygen species (ROS) in cotyledons and rosette leaves of Arabidopsis plants. Our results suggest that alloxan may destabilize cytoskeletal architecture via induction of an early transient ROS burst, further leading to the failure of molecular and cellular processes that are critical for plant immunity.

Styles APA, Harvard, Vancouver, ISO, etc.

17

Qin, Bi, Meng Wang, Hai-xia He, Hua-xing Xiao, Yu Zhang et Li-feng Wang. « Identification and Characterization of a Potential Candidate Mlo Gene Conferring Susceptibility to Powdery Mildew in Rubber Tree ». Phytopathology® 109, n^o 7 (juillet 2019) : 1236–45. http://dx.doi.org/10.1094/phyto-05-18-0171-r.

Texte intégral

Résumé :

Mildew resistance locus O (Mlo) gene was first found in barley as a powdery mildew susceptibility gene, and recessive mlo alleles confer durable resistance to barley powdery mildew. To identify candidate Mlo susceptibility genes in rubber tree, HbMlo12 was cloned from rubber tree clone CATAS7-33-97, which is susceptible to powdery mildew. Protein architecture analysis showed that HbMlo12 was a typical Mlo protein with seven transmembrane domains. Protein blast search in the Arabidopsis thaliana proteome database showed that HbMlo12 shared the highest similarity with AtMlo12, with 63% sequence identity. Furthermore, HbMlo12 together with the dicot powdery mildew susceptible Mlo proteins (including AtMlo2, AtMlo6, AtMlo12, tomato SlMlo1, pepper CaMlo2, pea PsMlo1, etc.) were grouped into clade V. Subcellular localization analysis in tobacco epidermal cells revealed that HbMlo12 was localized to the endoplasmic reticulum membrane. HbMlo12 was preferentially expressed in the flower and leaf of rubber tree. Moreover, its expression was significantly upregulated in response to powdery mildew inoculation. Application of exogenous ethephon caused a distinct increase in HbMlo12 expression. Additionally, HbMlo12 transcript was quickly induced by spraying salicylic acid and gibberellic acid and reached the maximum at 0.5 h after treatments. By contrast, HbMlo12 expression was downregulated by methyl jasmonate, abscisic acid, and drought stress treatments. There was no significant change in HbMlo12 expression after indole-3-acetic acid, H2O2, and wounding stimuli. Taken together, these results suggested that HbMlo12 might be a candidate Mlo gene conferring susceptibility to powdery mildew in rubber tree. The results of this study are vital in understanding Mlo gene evolution and developing new rubber tree varieties with powdery mildew resistance using reverse genetics.

Styles APA, Harvard, Vancouver, ISO, etc.

18

Zhu, Lei, Yanman Li, Jintao Li, Yong Wang, Zhenli Zhang, Yanjiao Wang, Zanlin Wang, Jianbin Hu, Luming Yang et Shouru Sun. « Genome-wide identification and analysis of the MLO gene families in three Cucurbita species ». Czech Journal of Genetics and Plant Breeding 57, No. 3 (14 juillet 2021) : 119–23. http://dx.doi.org/10.17221/99/2020-cjgpb.

Texte intégral

Résumé :

Powdery mildew (PM) is a major fungal disease in the Cucurbita species in the world, which can cause significant yield loss. The Mildew Locus O (MLO) family genes play important roles in the PM stress response. In this paper, twenty, twenty-one, and eighteen candidate MLO genes in Cucurbita moschata, Cucurbita maxima and Cucurbita pepo, respectively, were identified and designated as CmoMLO, CmaMLO and CpeMLO, respectively. The phylogenetic analysis indicated that these MLOs were divided into five clades and the number of MLOs belonging to clade V in the Cucurbita species was more than that in other crops. Furthermore, the expression analysis in the susceptibility (S) and resistance (R) lines showed that CpeMLO1, CpeMLO2 and CpeMLO5 might be involved in the susceptibility response. CpeMLO4 and CpeMLO6 showing opposite expression patterns in the R/S lines might be involved in the resistance response. All these data would be beneficial for future functional analysis of MLOs in the Cucurbita species.

Styles APA, Harvard, Vancouver, ISO, etc.

19

Geike, J., H. Kaufmann, F. Schürmann et T. Debener. « TARGETED MUTAGENESIS OF MLO-HOMOLOGOUS GENES IN THE ROSE GENOME ». Acta Horticulturae, n^o 1087 (juin 2015) : 507–13. http://dx.doi.org/10.17660/actahortic.2015.1087.68.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

20

Dreiseitl, Antonín. « Powdery Mildew Resistance Genes in Barley Varieties Bred for Human Consumption ». Agronomy 12, n^o 10 (20 septembre 2022) : 2245. http://dx.doi.org/10.3390/agronomy12102245.

Texte intégral

Résumé :

Barley has properties that can improve and maintain human health, but to upgrade the positive characteristics of grain, specific breeding programs are required. Consumption of chemically protected food is unpopular and, therefore, genetic sources of disease resistance to the most frequent diseases are essential. The aim of this contribution is to postulate genes for powdery mildew resistance in spring barley varieties bred for human consumption. One hundred and twenty-seven breeding strains selected from thirty-three crosses, commercial varieties AF Lucius and AF Cesar developed in the program, and eight other check varieties were tested with a set of numerous pathogen isolates. Fifteen known resistance genes were found including a nonspecific resistance Mlo detected in breeding lines selected from 21 crosses. For spring barley, the utilization of Mlo is generally recommended, but its importance in varieties earmarked for human consumption should be highlighted because alternative sources of genetically more complicated resistance, derived from distant relatives or based on the accumulation of minor genes, could be economically ineffective. The presented findings enable varieties for human consumption with fully effective and durable resistance to powdery mildew to be selected.

Styles APA, Harvard, Vancouver, ISO, etc.

21

Sabadyn, V. « Sources of valuable crop features of spring barley varieties for breeding in the central forest-steppe of Ukraine ». Agrobìologìâ, n^o 2(153) (18 décembre 2019) : 33–42. http://dx.doi.org/10.33245/2310-9270-2019-153-2-33-42.

Texte intégral

Résumé :

The population of Erysiphe graminis f. sp. hordei Em. Marchal, Bipolaris sorokiniana Shoem. and Drechslera teres Ito. was found to be the most widespread in the central forest-steppe of Ukraine. Drechslera graminea Ito and Puccinia hordei Otth. were not common. For an average of 7 years of research, the sources of the disease complex have been identified on a provocative background. Resistance (lesions up to 10.0 %) to two diseases – Erysiphe graminis and Drechslera teres were characterized by the following varieties: Etyket, Obolon, Parnas, Khadar, Edem, Pivdennyi, Koloryt (Ukraine), Josefin (France), Ebson, Malz, Aspen (Czech Republic), Barke, Bojos, Breemar, Brenda, Landora, Madeira, Danuta, Adonis, Сlass (Germany), Vivaldi, Eunova, Secuva (Austria). Complex resistance (lesions up to 10.0 %) to three diseases – Erysiphe graminis, Bipolaris sorokiniana and Drechslera teres were characterized by the following varieties: Aspekt, Dokaz (Ukraine), Hanka, Kuburas (Germany), STN 115 (Poland). The recessive genes mlo: mlo9, mlo11 and the combination of genes: mlo + Mla13 + Ml (La), mlo + Mla1 and mlo + Mla12 have been shown to be highly effective for Erysiphe graminis for a long time. High resistance and resistance were characterized by varieties protected by these resistance genes: Adonis, Barke, Bojos, Aspen, Сlass, Danuta, Eunova, Josefin, Breemar і Madeira. In spring barley varieties that showed disease resistance, structural analysis was performed by plant height, number of stems, spike length, number of grains, and weight of spikelets. In terms of length, number of grains and weight of grain of the main ear, the following varieties were better than the standard: Kuburas, Koloryt, Troichan, Barke, Danuta, Hanka, Ievroprestyzh, Sanktrum and others. Dedicated sources and donors of resistant varieties of spring barley to common pathogens can be used for immunity selection. Selected varieties by yield are the material for the selection of spring barley as a source of valuable features. These varieties are involved in hybridization. Key words: varieties, immunological monitoring, resistance, Erysiphe graminis, Bipolaris sorokiniana і Drechslera teres, valuable crop features, sources, donors.

Styles APA, Harvard, Vancouver, ISO, etc.

22

Wang, Ziyi, Yao Weng, Yoshihito Ishihara, Naoya Odagaki, Ei Ei Hsu Hlaing, Takashi Izawa, Hirohiko Okamura et Hiroshi Kamioka. « Loading history changes the morphology and compressive force-induced expression of receptor activator of nuclear factor kappa B ligand/osteoprotegerin in MLO-Y4 osteocytes ». PeerJ 8 (9 novembre 2020) : e10244. http://dx.doi.org/10.7717/peerj.10244.

Texte intégral

Résumé :

Background In this study, we investigated the effect of the mechanical loading history on the expression of receptor activator of nuclear factor kappa B ligand (RANKL) and osteoprotegerin (OPG) in MLO-Y4 osteocyte-like cells. Methods Three hours after MLO-Y4 osteocytes were seeded, a continuous compressive force (CCF) of 31 dynes/cm2 with or without additional CCF (32 dynes/cm2) was loaded onto the osteocytes. After 36 h, the additional CCF (loading history) was removed for a recovery period of 10 h. The expression of RANKL, OPG, RANKL/OPG ratio, cell numbers, viability and morphology were time-dependently examined at 0, 3, 6 and 10 h. Then, the same additional CCF was applied again for 1 h to all osteocytes with or without the gap junction inhibitor to examine the expression of RANKL, OPG, the RANKL/OPG ratio and other genes that essential to characterize the phenotype of MLO-Y4 cells. Fluorescence recovery after photobleaching technique was also applied to test the differences of gap-junctional intercellular communications (GJIC) among MLO-Y4 cells. Results The expression of RANKL and OPG by MLO-Y4 osteocytes without a loading history was dramatically decreased and increased, respectively, in response to the 1-h loading of additional weight. However, the expression of RANKL, OPG and the RANKL/OPG ratio were maintained at the same level as in the control group in the MLO-Y4 osteocytes with a loading history but without gap junction inhibitor treatment. Treatment of loading history significantly changed the capacity of GJIC and protein expression of connexin 43 (Cx43) but not the mRNA expression of Cx43. No significant difference was observed in the cell number or viability between the MLO-Y4 osteocyte-like cells with and without a loading history or among different time checkpoints during the recovery period. The cell morphology showed significant changes and was correlated with the expression of OPG, Gja1 and Dmp1 during the recovery period. Conclusion Our findings indicated that the compressive force-induced changes in the RANKL/OPG expression could be habituated within at least 11 h by 36-h CCF exposure. GJIC and cell morphology may play roles in response to loading history in MLO-Y4 osteocyte-like cells.

Styles APA, Harvard, Vancouver, ISO, etc.

23

Collins, N. C., R. E. Niks et P. Schulze-Lefert. « Resistance to cereal rusts at the plant cell wall—what can we learn from other host-pathogen systems ? » Australian Journal of Agricultural Research 58, n^o 6 (2007) : 476. http://dx.doi.org/10.1071/ar06065.

Texte intégral

Résumé :

The ability of plant cells to resist invasion by pathogenic fungi at the cell periphery (pre-invasion resistance) differs from other types of resistance that are generally triggered after parasite entry and during differentiation of specialised intracellular feeding structures. Genetic sources of pre-invasion resistance such as mlo for barley powdery mildew and Lr34 for resistance to wheat leaf rust have proven to be broad-spectrum in effect and durable in the field. Continued breeding for this type of resistance (often quantitative in effect) is therefore considered an important strategy to protect cereal crops long-term against potentially devastating fungal diseases such as rusts. Considerable progress has been made in characterising genes and processes underlying pre-invasion resistance using mutant analysis, molecular genetics, gene cloning, and the model plant Arabidopsis, as well as comparative functional analysis of genes in Arabidopsis and cereals. This review summarises the current knowledge in this field, and discusses several aspects of pre-invasion resistance potentially pertinent to use in breeding; namely, biological cost of the resistance and effectiveness of individual resistance genes against multiple pathogen types. We show that mutations in Mlo, Ror1, and Ror2 genes known to affect powdery mildew pre-invasion resistance have no detectable effect on partial resistance to barley leaf rust as measured by latency period.

Styles APA, Harvard, Vancouver, ISO, etc.

24

MOHAPATRA, Chinmayee, Ramesh CHAND, Vinay Kumar SINGH, Anil Kumar SINGH et Chanda KUSHWAHA. « Identification and characterisation of Mlo genes in pea (Pisum sativum L.)vis-à-vis validation of Mlo gene-specific markers ». TURKISH JOURNAL OF BIOLOGY 40 (2016) : 184–95. http://dx.doi.org/10.3906/biy-1501-29.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

25

Polanco, Carlos, Luis E. Sáenz de Miera, Kirstin Bett et Marcelino Pérez de la Vega. « A genome-wide identification and comparative analysis of the lentil MLO genes ». PLOS ONE 13, n^o 3 (23 mars 2018) : e0194945. http://dx.doi.org/10.1371/journal.pone.0194945.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

26

Davis, Thomas C., Daniel S. Jones, Arianna J. Dino, Nicholas I. Cejda, Jing Yuan, Andrew C. Willoughby et Sharon A. Kessler. « Arabidopsis thaliana MLO genes are expressed in discrete domains during reproductive development ». Plant Reproduction 30, n^o 4 (20 novembre 2017) : 185–95. http://dx.doi.org/10.1007/s00497-017-0313-2.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

27

Howlader, Jewel, Jong-In Park, Hoy-Taek Kim, Nasar Uddin Ahmed, Arif Hasan Khan Robin, Kanij Rukshana Sumi, Sathishkumar Natarajan et Ill-Sup Nou. « Differential Expression under Podosphaera xanthii and Abiotic Stresses Reveals Candidate MLO Family Genes in Cucumis melo L ». Tropical Plant Biology 10, n^o 4 (4 novembre 2017) : 151–68. http://dx.doi.org/10.1007/s12042-017-9194-7.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

28

Feechan, Angela, Angelica M. Jermakow, Laurent Torregrosa, Ralph Panstruga et Ian B. Dry. « Identification of grapevine MLO gene candidates involved in susceptibility to powdery mildew ». Functional Plant Biology 35, n^o 12 (2008) : 1255. http://dx.doi.org/10.1071/fp08173.

Texte intégral

Résumé :

The European cultivated grapevine, Vitis vinifera L., is a host for the powdery mildew pathogen Erisyphe necator, which is the most economically important fungal disease of viticulture. MLO proteins mediate powdery mildew susceptibility in the model plant species Arabidopsis and the crop plants barley and tomato. Seven VvMLO cDNA sequences were isolated from grapevine and were subsequently identified as part of a 17 member VvMLO gene family within the V. vinifera genome. Phylogenetic analysis of the 17 VvMLO genes in the grape genome indicated that the proteins they encode fall into six distinct clades. The expression of representative VvMLOs from each clade were analysed in a range of grape tissues, as well as in response to a range of biotic and abiotic factors. The VvMLOs investigated have unique, but overlapping tissue expression patterns. Expression analysis of VvMLO genes following E. necator infection identified four upregulated VvMLOs which are orthologous to the Arabidopsis AtMLO2, AtMLO6 and AtMLO12 and tomato SlMLO1 genes required for powdery mildew susceptibility. This suggests a degree of functional redundancy between the proteins encoded by these genes in terms of susceptibility to powdery mildew, and, as such, represent potential targets for modification to generate powdery mildew resistant grapevines.

Styles APA, Harvard, Vancouver, ISO, etc.

29

Czembor, J. H., et H. J. Czembor. « Selections from barley landrace collected in Libya as new sources of effective resistance to powdery mildew (Blumeria graminis f.sp. hordei) ». Plant, Soil and Environment 48, No. 5 (11 décembre 2011) : 217–23. http://dx.doi.org/10.17221/4229-pse.

Texte intégral

Résumé :

Powdery mildew on barley (Hordeum vulgare L.) caused by the pathogen Blumeria graminis f.sp. hordei occurs worldwide and can result in severe yield loss. Because agronomical methods to control the disease are not completely effective, cultivars with genetic resistance are needed. Therefore, there is a need to describe new sources of genes that confer resistance to barley powdery mildew. This study was conducted to determine the genetic basis of resistance to powdery mildew in three selections 995-1-1, 995-1-2, 995-1-3 from barley landrace 995 (ICB 112840) collected in Al Aziziyah district, Tripolitania, Libya. Landrace originated from InternationalCenter for Agricultural Research in the Dry Areas – ICARDA, Aleppo, Syria. To determine the number of genes, the types of genes action and the gene loci in tested lines two types of crosses were made: (1) the lines were crossed to the susceptible cultivar Pallas, (2) the lines were crossed with Pallas isoline P22 carrying gene mlo5. The parents and progeny F2 were evaluated with isolate R303.1 for the powdery mildew resistance. Based on segregation ratios we found that resistance in these three selections was determined by a single recessive gene allelic to the Mlo locus occurring in Pallas isoline P22. In addition tested lines showed resistance reaction type 0(4) characteristic only for genes mlo. The value of new identified sources of highly effective powdery mildew resistance to breeding programs and barley production is discussed.

Styles APA, Harvard, Vancouver, ISO, etc.

30

Howlader, Jewel, Hoy-Taek Kim, Jong-In Park, Nasar Uddin Ahmed, Arif Hasan Khan Robin, Hee-Jeong Jung et III-Sup Nou. « Expression Profiling of MLO Family Genes under Podosphaera xanthii Infection and Exogenous Application of Phytohormones in Cucumis melo L. » Journal of Life Science 26, n^o 4 (30 avril 2016) : 419–30. http://dx.doi.org/10.5352/jls.2016.26.4.419.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

31

Mejlhede, N., Z. Kyjovska, G. Backes, K. Burhenne, S. K. Rasmussen et A. Jahoor. « EcoTILLING for the identification of allelic variation in the powdery mildew resistance genes mlo and Mla of barley ». Plant Breeding 125, n^o 5 (octobre 2006) : 461–67. http://dx.doi.org/10.1111/j.1439-0523.2006.01226.x.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

32

Dreiseitl, A. « Adaptation of Blumeria graminis f.sp. hordei to barley resistance genes in the Czech Republic in 1971–2000 ». Plant, Soil and Environment 49, No. 6 (10 décembre 2011) : 241–48. http://dx.doi.org/10.17221/4120-pse.

Texte intégral

Résumé :

Results of scoring the resistance of 35 selected spring barley varieties to powdery mildew, exhibiting high powdery mildew severity, in 307 variety trials of the Central Institute for Supervising and Testing in Agriculture were analysed. The varieties can be divided into two groups: the varieties that could not induce any changes in the pathogen population (the varieties with no effective resistance gene and varieties carrying gene mlo) and the varieties possessing major resistance genes [a total of 12 Ml-genes: a1, a3, a6, a7, a9, a12, a13, at, k1, La, g and (Kr)] to which the pathogen population adapted in 1971–2000. The time slope of decreasing resistance of varieties is described. The importance of individual evolutionary forces (mutations, migration, direct selection, indirect selection and recombinations) for the erosion of efficiency of respective major resistance genes and the effects of pathogen adaptation on population complexity and diversity are discussed.

Styles APA, Harvard, Vancouver, ISO, etc.

33

Zurn, J. D., R. Meiers, J. Ward, C. E. Finn, M. Dossett et N. V. Bassil. « Identifying variation in red raspberry MLO genes thought to provide resistance to powdery mildew ». Acta Horticulturae, n^o 1277 (avril 2020) : 25–32. http://dx.doi.org/10.17660/actahortic.2020.1277.4.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

34

Shen, Qi, Jinming Zhao, Caifu Du, Yang Xiang, Jinxuan Cao et Xinrong Qin. « Genome-scale identification of MLO domain-containing genes in soybean (Glycine max L. Merr.) ». Genes ^|^ Genetic Systems 87, n^o 2 (2012) : 89–98. http://dx.doi.org/10.1266/ggs.87.89.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

35

Várallyay, Éva, Gábor Giczey et József Burgyán. « Virus-induced gene silencing of Mlo genes induces powdery mildew resistance in Triticum aestivum ». Archives of Virology 157, n^o 7 (24 mars 2012) : 1345–50. http://dx.doi.org/10.1007/s00705-012-1286-y.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

36

Win, Khin Thanda, Chunying Zhang et Sanghyeob Lee. « Genome-wide identification and description of MLO family genes in pumpkin (Cucurbita maxima Duch.) ». Horticulture, Environment, and Biotechnology 59, n^o 3 (30 avril 2018) : 397–410. http://dx.doi.org/10.1007/s13580-018-0036-9.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

37

Jarosch, Birgit, Nicholas C. Collins, Nina Zellerhoff et Ulrich Schaffrath. « RAR1, ROR1, and the Actin Cytoskeleton Contribute to Basal Resistance to Magnaporthe grisea in Barley ». Molecular Plant-Microbe Interactions® 18, n^o 5 (mai 2005) : 397–404. http://dx.doi.org/10.1094/mpmi-18-0397.

Texte intégral

Résumé :

The fungus Magnaporthe grisea, the causal agent of rice blast disease, is a major pathogen of rice and is capable of producing epidemics on other cultivated cereals, including barley (Hordeum vulgare). We explored the requirements for basal resistance of barley against a compatible M. grisea isolate using both genetic and chemical approaches. Mutants of the RAR1 gene required for the function of major resistance gene-mediated resistance and mutants of the ROR1 and ROR2 genes required for full expression of cell-wall-penetration resistance against powdery mildew pathogens were examined for macroscopic and microscopic alterations in M. grisea growth and symptoms. RAR1 contributed to resistance in epidermis and mesophyll at different stages of fungal infection dependent on the MLO/mlo-5 status. Whereas no ROR2 effect was detected, ROR1 was found to contribute to cell-wall-penetration resistance, at least in the epidermis. Application of the actin agonist cytochalasin E promoted cell wall penetration by M. grisea in a dose-dependent manner, demonstrating an involvement of the actin cytoskeleton in penetration resistance.

Styles APA, Harvard, Vancouver, ISO, etc.

38

Dreiseitl, Antonín. « High diversity of powdery mildew resistance in the ICARDA wild barley collection ». Crop and Pasture Science 68, n^o 2 (2017) : 134. http://dx.doi.org/10.1071/cp16221.

Texte intégral

Résumé :

Powdery mildew caused by the fungus Blumeria graminis f. sp. hordei (Bgh) is a global disease of barley, and the wild subspecies Hordeum vulgare subsp. spontaneum (Hvs) is the closest relative of cultivated barley (H. vulgare subsp. vulgare). The responses to the pathogen of 363 Hvs accessions maintained by the International Center for Agricultural Research in the Dry Areas (ICARDA) gene bank were assessed. Thirty non-Israeli pathogen isolates representing the global pathogenic diversity were used for testing. Because of genetic heterogeneity within 146 accessions, the results from only 217 accessions are presented and discussed. Additional tests on 152 accessions with homogeneous responses in earlier tests were made by using six Israeli pathogen isolates. There were 154 resistance phenotypes among the set, 141 of which involved single accessions. The six most frequent phenotypes were recorded for 62 accessions, with the most frequent phenotype in 26 accessions that were resistant to all 30 non-Israeli Bgh isolates. The second most frequent phenotype, found in 16 accessions, was susceptible to all 30 non-Israeli isolates. The occurrence of specific resistance was high. The occurrence of specific resistance was high and for breeding barley cultivars the effective resistances can be combined with the resistance gene mlo. In such combinations, the mlo gene prevents rapid increase in the pathogen population from overcoming the given specific resistance, whereas the resistance gene will simultaneously prevent erosion of mlo resistance. A more effective method for achieving durable resistance is accumulation minor resistance genes that are also widely distributed in wild barley.

Styles APA, Harvard, Vancouver, ISO, etc.

39

Dreiseitl, Antonín, Amos Dinoor et Evsey Kosman. « Virulence and Diversity of Blumeria graminis f. sp. hordei in Israel and in the Czech Republic ». Plant Disease 90, n^o 8 (août 2006) : 1031–38. http://dx.doi.org/10.1094/pd-90-1031.

Texte intégral

Résumé :

Three hundred and nine isolates were obtained from three natural populations of Blumeria graminis f. sp. hordei occurring on wild barley (Hordeum vulgare subsp. spontaneum) at two locations in Israel during 1997 and 1999. Their virulence frequency was determined on 32 differential lines. No isolate was virulent on the differential lines possessing the genes Mla13, mlo, Mlf1, and Mli, and conversely no isolate was avirulent on the differential lines possessing the genes MlRu2, MlLa, Mlh, Mla8, Mla25, and Mlj. The frequencies of isolates overcoming the genes Mlg, Mla7, and Mla27 were 0 to 16% at individual locations; frequencies of isolates overcoming the genes Mla9, Mla17, and Mla18 ranged from 37 to 78%, and frequencies of virulences to genes Mla1, Mla3, Mla6, Mlp1, Mlat, Mla12, Mlra, Mlk1, Mla19, Mla20, Mla26, Mla28, Mla29, Mla30, Mla32, and mlt1 were 79 to 99%. Based on examination of 376 isolates collected in the same years from the Czech Republic, these populations differed greatly from the Israeli ones. The Czech populations showed greater diversity of virulence and lower mean virulence complexity than the Israeli populations. Diversity in the Israeli populations differed also among clusters of niches at the same location.

Styles APA, Harvard, Vancouver, ISO, etc.

40

Yang, Sheng, Yuanyuan Shi, Longyun Zou, Jinfeng Huang, Lei Shen, Yuzhu Wang, Deyi Guan et Shuilin He. « Pepper CaMLO6 Negatively Regulates Ralstonia solanacearum Resistance and Positively Regulates High Temperature and High Humidity Responses ». Plant and Cell Physiology 61, n^o 7 (28 avril 2020) : 1223–38. http://dx.doi.org/10.1093/pcp/pcaa052.

Texte intégral

Résumé :

Abstract Plant mildew-resistance locus O (MLO) proteins influence susceptibility to powdery mildew. However, their roles in plant responses to other pathogens and heat stress remain unclear. Here, we showed that CaMLO6, a pepper (Capsicum annuum) member of MLO clade V, is a protein targeted to plasma membrane and probably endoplasmic reticulum. The transcript expression level of CaMLO6 was upregulated in the roots and leaves of pepper plants challenged with high temperature and high humidity (HTHH) and was upregulated in leaves but downregulated in roots of plants infected with the bacterial pathogen Ralstonia solanacearum. CaMLO6 was also directly upregulated by CaWRKY40 upon HTHH but downregulated by CaWRKY40 upon R. solanacearum infection. Virus-induced gene silencing of CaMLO6 significantly decreased pepper HTHH tolerance and R. solanacearum susceptibility. Moreover, CaMLO6 overexpression enhanced the susceptibility of Nicotiana benthamiana and pepper plants to R. solanacearum and their tolerance to HTHH, effects that were associated with the expression of immunity- and thermotolerance-associated marker genes, respectively. These results suggest that CaMLO6 acts as a positive regulator in response to HTHH but a negative regulator in response to R. solanacearum. Moreover, CaMLO6 is transcriptionally affected by R. solanacearum and HTHH; these transcriptional responses are at least partially regulated by CaWRKY40.

Styles APA, Harvard, Vancouver, ISO, etc.

41

Hu, Pingsha, Yan Meng et Roger P. Wise. « Functional Contribution of Chorismate Synthase, Anthranilate Synthase, and Chorismate Mutase to Penetration Resistance in Barley–Powdery Mildew Interactions ». Molecular Plant-Microbe Interactions® 22, n^o 3 (mars 2009) : 311–20. http://dx.doi.org/10.1094/mpmi-22-3-0311.

Texte intégral

Résumé :

Plant processes resulting from primary or secondary metabolism have been hypothesized to contribute to defense against microbial attack. Barley chorismate synthase (HvCS), anthranilate synthase α subunit 2 (HvASa2), and chorismate mutase 1 (HvCM1) occupy pivotal branch points downstream of the shikimate pathway leading to the synthesis of aromatic amino acids. Here, we provide functional evidence that these genes contribute to penetration resistance to Blumeria graminis f. sp. hordei, the causal agent of powdery mildew disease. Single-cell transient-induced gene silencing of HvCS and HvCM1 in mildew resistance locus a (Mla) compromised cells resulted in increased susceptibility. Correspondingly, overexpression of HvCS, HvASa2, and HvCM1 in lines carrying mildew resistance locus o (Mlo), a negative regulator of penetration resistance, significantly decreased susceptibility. Barley stripe mosaic virus–induced gene silencing of HvCS, HvASa2, and HvCM1 significantly increased B. graminis f. sp. hordei penetration into epidermal cells, followed by formation of haustoria and secondary hyphae. However, sporulation of B. graminis f. sp. hordei was not detected on the silenced host plants up to 3 weeks after inoculation. Taken together, these results establish a previously unrecognized role for the influence of HvCS, HvASa2, and HvCM1 on penetration resistance and on the rate of B. graminis f. sp. hordei development in Mla-mediated, barley–powdery mildew interactions.

Styles APA, Harvard, Vancouver, ISO, etc.

42

Chen, Zhihao, Fan Zhao, Yiduo Qi, Lifang Hu, Dijie Li, Chong Yin, Peihong Su et al. « Simulated microgravity alters the expression of cytoskeleton- and ATP-binding-related genes in MLO-Y4 osteocytes ». Acta Astronautica 129 (décembre 2016) : 186–92. http://dx.doi.org/10.1016/j.actaastro.2016.09.017.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

43

Dreiseitl, Antonín. « Specific Resistance of Barley to Powdery Mildew, Its Use and Beyond : A Concise Critical Review ». Genes 11, n^o 9 (21 août 2020) : 971. http://dx.doi.org/10.3390/genes11090971.

Texte intégral

Résumé :

Powdery mildew caused by the airborne ascomycete fungus Blumeria graminis f. sp. hordei (Bgh) is one of most common diseases of barley (Hordeum vulgare). This, as with many other plant pathogens, can be efficiently controlled by inexpensive and environmentally-friendly genetic resistance. General requirements for resistance to the pathogens are effectiveness and durability. Resistance of barley to Bgh has been studied intensively, and this review describes recent research and summarizes the specific resistance genes found in barley varieties since the last conspectus. Bgh is extraordinarily adaptable, and some commonly recommended strategies for using genetic resistance, including pyramiding of specific genes, may not be effective because they can only contribute to a limited extent to obtain sufficient resistance durability of widely-grown cultivars. In spring barley, breeding the nonspecific mlo gene is a valuable source of durable resistance. Pyramiding of nonspecific quantitative resistance genes or using introgressions derived from bulbous barley (Hordeum bulbosum) are promising ways for breeding future winter barley cultivars. The utilization of a wide spectrum of nonhost resistances can also be adopted once practical methods have been developed.

Styles APA, Harvard, Vancouver, ISO, etc.

44

Yu, Guangchao, Qiumin Chen, Xiangyu Wang, Xiangnan Meng, Yang Yu, Haiyan Fan et Na Cui. « Mildew Resistance Locus O Genes CsMLO1 and CsMLO2 Are Negative Modulators of the Cucumis sativus Defense Response to Corynespora cassiicola ». International Journal of Molecular Sciences 20, n^o 19 (26 septembre 2019) : 4793. http://dx.doi.org/10.3390/ijms20194793.

Texte intégral

Résumé :

Corynespora leaf spot caused by Corynespora cassiicola is one of the major diseases in cucumber (Cucumis sativus L.). However, the resistance mechanisms and signals of cucumber to C. cassiicola are unclear. Here, we report that the mildew resistance locus O (MLO) genes, CsMLO1 and CsMLO2, are both negative modulators of the cucumber defense response to C. cassiicola. Subcellular localization analysis showed that CsMLO1 and CsMLO2 are localized in the plasma membrane. Expression analysis indicated that the transcript levels of CsMLO1 and CsMLO2 are linked to the defense response to C. cassiicola. Transient overexpression of either CsMLO1 or CsMLO2 in cucumber cotyledons reduced resistance to C. cassiicola, whereas silencing of either CsMLO1 or CsMLO2 enhanced resistance to C. cassiicola. The relationships of pathogenesis-related proteins, reactive oxygen species (ROS)-associated genes, and abscisic acid (ABA)-related genes to the overexpression and silencing of CsMLO1/CsMLO2 in non-infested cucumber plants were investigated. The results indicated that CsMLO1 mediated resistance against C. cassiicola by regulating the expression of pathogenesis-related proteins and ROS-associated genes, as well as through ABA signaling pathway-associated genes. The CsMLO2-mediated resistance against C. cassiicola primarily involves regulation of the expression of pathogenesis-related proteins. Our findings will guide strategies to enhance the resistance of cucumber to corynespora leaf spot.

Styles APA, Harvard, Vancouver, ISO, etc.

45

Deshmukh, Reena, V. K. Singh et Brahma Deo Singh. « Mining the Cicer arietinum genome for the mildew locus O (Mlo) gene family and comparative evolutionary analysis of the Mlo genes from Medicago truncatula and some other plant species ». Journal of Plant Research 130, n^o 2 (30 novembre 2016) : 239–53. http://dx.doi.org/10.1007/s10265-016-0868-2.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

46

Appiano, Michela, Stefano Pavan, Domenico Catalano, Zheng Zheng, Valentina Bracuto, Concetta Lotti, Richard G. F. Visser, Luigi Ricciardi et Yuling Bai. « Identification of candidate MLO powdery mildew susceptibility genes in cultivated Solanaceae and functional characterization of tobacco NtMLO1 ». Transgenic Research 24, n^o 5 (7 mai 2015) : 847–58. http://dx.doi.org/10.1007/s11248-015-9878-4.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

47

Islam, Md Zaherul, et HaeKeun Yun. « Characterization of nine Mlo family genes and analysis of their expression against pathogen infections in Vitis flexuosa ». Euphytica 211, n^o 3 (5 août 2016) : 379–94. http://dx.doi.org/10.1007/s10681-016-1752-9.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

48

Dreiseitl, A., et P. Pařízek. « Resistance of Spring Barley Varieties to Powdery Mildew in theCzechRepublicin 1971–2000 ». Czech Journal of Genetics and Plant Breeding 39, No. 2 (23 novembre 2011) : 31–44. http://dx.doi.org/10.17221/3718-cjgpb.

Texte intégral

Résumé :

Resistance to powdery mildew of 127 spring barley varieties was evaluated in 702 official variety trials, using scores from 1 to 9. Trials with sufficient disease severity were only analysed. Varieties possessing the resistance genes Mla7 (Elgina), Ml(Kr) (BR-1519), Mla13 (Koral) and mlo (Forum) were among the most resistant ones. The varieties Diamant, HE-3527, HE-3631, II/61-FUDII and Zefir showed high susceptibility. Fifteen varieties, carrying the genes Mla1, Mla3, Mla6, Mla9, Mla13, Ml(Kr) and Ml(Sc), were in the first years of testing highly resistant, but became susceptible later. The score of the most resistant variety ranged each year from 8.05 to 9.00, only in 1987–1991 it was lower. Since the pathogen population rapidly adapted to most resistance genes in the mid eighties, no resistant variety was found in 1987–1989. From 1986 to 1995 on average only 6.6% of the tested varieties were resistant, but there was no variety with resistance score above 8.50. High resistance was typical for varieties possessing an effective major resistance gene. Since the resistance of such varieties was not durable, we recommend breeding of varieties with at least two fully effective resistance genes, using molecular markers.  

Styles APA, Harvard, Vancouver, ISO, etc.

49

Freialdenhoven, Andreas, Christoph Peterhansel, Joachim Kurth, Fritz Kreuzaler et Paul Schulze-Lefert. « Identification of Genes Required for the Function of Non-Race-Specific mlo Resistance to Powdery Mildew in Barley ». Plant Cell 8, n^o 1 (janvier 1996) : 5. http://dx.doi.org/10.2307/3870064.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

50

Abdullaev, R. A., N. V. Alpatieva, T. V. Lebedeva, O. N. Kovaleva, E. E. Radchenko et I. N. Anisimova. « Identification of barley accessions from the VIR collection carrying the <i>mlo11(cnv2)</i> ; powdery mildew resistance allele ». Plant Biotechnology and Breeding 4, n^o 3 (14 décembre 2021) : 37–44. http://dx.doi.org/10.30901/2658-6266-2021-3-o3.

Texte intégral

Résumé :

Background. The search for barley (Hordeum vulgare L.) genotypes that carry effective genes for resistance to powdery mildew agent Blumeria graminis f. sp. hordei is a present-day issue for Russian plant breeding. The mlo11 allele that confers long-term protection of barley against the pathogen is rarely found among the varieties, approved for cultivation in the territory of Russia. There is no information on the occurrence among Russian varieties of another effective allele, mlo11 (cnv2), therefore, the search for its source is a current necessity. Materials and methods. Seven barley accessions from Ethiopia and 7 accessions from Japan have been tested for resistance to the northwestern population of the powdery mildew agent in the field and in laboratory conditions. To identify of the Mlo gene alleles, nucleotide sequences of the Stowaway-MITE (Miniature Inverted-repeat Transposable Elements) and the adjacent promoter fragments were determined. Results. Phytopathological tests in the field and greenhouse conditions, as well as molecular markers were used to study 14 barley accessions from Ethiopia and Japan. According to the preliminary tests, plants were resistant to powdery mildew. The highly effective allele of powdery mildew resistance mlo11 (cnv2) was for the first time identified in four barley accessions from Ethiopia, k-20087, k-20523, k-20524 and k-28126. Under field conditions, adult plants were resistant, and in the greenhouse they were moderately damaged by powdery mildew (1-2 points). The disease symptoms were similar to those described for the sample Eth295, a carrier of the mlo11(cnv2) allele variant: single pustules and the absence of necrotic spots on the leaves. The fragments of Stowaway-MITE and adjacent Mlo 5' promoter sequences were amplified in all 14 accessions. The amplicons were cloned and sequenced. The unique marker SNPs within the MITE and Mlo 5’ promoter sequences, i.e. the substitutions of cytosine by thymine in positions 262 and 452, were found only in k-20087, k-20523, k-20524 and k-28126. These accessions belong to different botanical varieties and differ from each other in a number of morphological features, i.e. they are not duplicates. Conclusions. The genotypes selected as a result of the study can serve as a source of the mlo11(cnv2) allele in breeding powdery mildew-resistant barley varieties.

Styles APA, Harvard, Vancouver, ISO, etc.

Articles de revues sur le sujet « Mlo genes »

Créez une référence correcte selon les styles APA, MLA, Chicago, Harvard et plusieurs autres