Journal articles: 'Auxines de synthèse'

1

Yu, Min, Kai Liu, Shengquan Liu, Haiyan Chen, Liang Zhou, and Yamei Liu. "Effect of exogenous IAA on tension wood formation by facilitating polar auxin transport and cellulose biosynthesis in hybrid poplar (Populus deltoids × Populus nigra) wood." Holzforschung 71, no. 2 (February 1, 2017): 179–88. http://dx.doi.org/10.1515/hf-2016-0078.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Abstract Auxins as phytohormons, responsible for coordination of growing processes, also contribute to the formation of tension wood (TW) in trees, but the mechanism of this process is still unclear. In this study, it has been tried to induce TW formation in erect hybrid poplar trees (in opposite to inclined or bended trees) by treatment with exogenous indole-3-acetic acid (IAA, as one of the auxins) or N-1-naphthylphthalamic acid (NPA) as an auxin transport inhibitor. The treatment with IAA resulted in TW formation and, as expected, NPA treatment did not. The gelatinous fiber formation and higher cellulose content in the cell wall were unambiguous indicators for TW formation. Real-time polymerase chain reaction (PCR) analysis revealed that genes of PIN1, ABCB1, and AUX2 involved in polar auxin transport were highly expressed in trees treated with exogenous IAA. Moreover, expressions of cellulose biosynthesis related genes of UGP1, UGP2 and CesA13 were strongly up-regulated. These observations indicate that the accelerated intercellular polar auxin transport caused by exogenous IAA is accounted for TW formation, i.e. the signal transduction of auxin is affected, which then facilitates cellulose biosynthesis. In contrast, the transcript abundances of PIN1 and all selected cellulose synthases (CesAs) were decreased after NPA treatment via inhibiting the cellular auxin efflux with negative effects on plant’s primary growth. These results are interpreted that TW formation is closely associated with the acceleration of intercellular polar auxin transport.

2

Grossmann, Klaus. "Quinclorac belongs to a new class of highly selective auxin herbicides." Weed Science 46, no. 6 (December 1998): 707–16. http://dx.doi.org/10.1017/s004317450008975x.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Substituted quinolinecarboxylic acids, including quinclorac (BAS 514H), are a new class of highly selective auxin herbicides, which are chemically similar to naturally occurring compounds isolated from plants and soils. Quinclorac is used in rice to control important dicot and monocot weeds, particularly barnyardgrass. The herbicide has also been developed for application in turfgrass areas, spring wheat, and chemical fallow. Quinclorac is readily absorbed by germinating seeds, roots, and leaves and is translocated in the plant both acropetally and basipetally. By mimicking an auxin overdose, quinclorac affects the phytohormonal system in sensitive plants. The compound stimulates the induction of 1-aminocyclopropane-1-carboxylic acid (ACC) synthase activity and thus promotes ethylene biosynthesis. In susceptible dicots, increased levels of ethylene trigger an accumulation of abscisic acid (ABA), which, as part of the intrinsic auxin activity of quinclorac, plays a major role in growth inhibition and the induction of epinasty and senescence. In sensitive grasses, such as barnyardgrass species, large crabgrass, broadleaf signalgrass, and green foxtail, quinclorac leads particularly to an accumulation of tissue cyanide, formed as a co-product during increased ACC and ethylene synthesis. This causes phytotoxicity characterized by the inhibition of root and particularly shoot growth with tissue chlorosis and subsequent necrosis. These effects were not observed in tolerant rice and a resistant biotype of barnyardgrass. No significant differences in uptake, translocation, or metabolism of quinclorac between resistant and sensitive grasses were found. Hence, a target-site-based mechanism of selectivity is suggested. The induction process of the ACC synthase activity plays the primary role in the selective herbicide action of quinclorac. This is a common effect of auxin herbicides and auxins, which lead to the accumulation of cyanide and/or ABA depending on the plant species and tissues, the compound concentration in the tissue, and their biological activity.

3

Abu-Zaitoon, Yousef M., Ezz Al-Dein Muhammed Al-Ramamneh, Abdel Rahman Al Tawaha, Sulaiman M. Alnaimat, and Fouad A. Almomani. "Comparative Coexpression Analysis of Indole Synthase and Tryptophan Synthase A Reveals the Independent Production of Auxin via the Cytosolic Free Indole." Plants 12, no. 8 (April 18, 2023): 1687. http://dx.doi.org/10.3390/plants12081687.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Indole synthase (INS), a homologous cytosolic enzyme of the plastidal tryptophan synthase A (TSA), has been reported as the first enzyme in the tryptophan-independent pathway of auxin synthesis. This suggestion was challenged as INS or its free indole product may interact with tryptophan synthase B (TSB) and, therefore, with the tryptophan-dependent pathway. Thus, the main aim of this research was to find out whether INS is involved in the tryptophan-dependent or independent pathway. The gene coexpression approach is widely recognized as an efficient tool to uncover functionally related genes. Coexpression data presented here were supported by both RNAseq and microarray platforms and, hence, considered reliable. Coexpression meta-analyses of Arabidopsis genome was implemented to compare between the coexpression of TSA and INS with all genes involved in the production of tryptophan via the chorismate pathway. Tryptophan synthase A was found to be coexpressed strongly with TSB1/2, anthranilate synthase A1/B1, phosphoribosyl anthranilate transferase1, as well as indole-3-glycerol phosphate synthase1. However, INS was not found to be coexpressed with any target genes suggesting that it may exclusively and independently be involved in the tryptophan-independent pathway. Additionally, annotation of examined genes as ubiquitous or differentially expressed were described and subunits-encoded genes available for the assembly of tryptophan and anthranilate synthase complex were suggested. The most probable TSB subunits expected to interact with TSA is TSB1 then TSB2. Whereas TSB3 is only used under limited hormone conditions to assemble tryptophan synthase complex, putative TSB4 is not expected to be involved in the plastidial synthesis of tryptophan in Arabidopsis.

4

Lindstrom, Jon T., Chih-Hsien Lei, Michelle L. Jones, and William R. Woodson. "Accumulation of 1-Aminocyclopropane-1-carboxylic acid (ACC) in Petunia Pollen is Associated with Expression of a Pollen-specific ACC Synthase Late in Development." Journal of the American Society for Horticultural Science 124, no. 2 (March 1999): 145–51. http://dx.doi.org/10.21273/jashs.124.2.145.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Mature pollen from Petunia hybrida contains significant levels of 1-aminocyclopropane-1-carboxylic acid (ACC), and this ACC is thought to play a role in pollination-induced ethylene by the pistil. We investigated the developmental accumulation of ACC in anthers and pollen. The level of ACC in anthers was very low until the day before anthesis, at which time it increased 100-fold. A 1.1-kb partial ACC synthase cDNA clone (pPHACS2) was amplified from total RNA isolated from mature anthers by reverse transcriptase, followed by polymerase chain reaction using oligonucleotide primers synthesized to conserved amino acid sequences in ACC synthases. The expression of pPHACS2 mRNA during anther development was correlated with the accumulation of ACC and was localized to the pollen grain. The pPHACS2 cDNA was used to identify the PH-ACS2 gene from a library of genomic DNA fragments from Petunia hybrida. PH-ACS2 encoded an ACC synthase transcript of four exons interrupted by three introns. The ACC synthase protein encoded by the PH-ACS2 gene shared >80% homology with ACC synthases from tomato (LE-ACS3) and potato (ST-ACS1a). A chimeric PH-ACS2 promoter-β-glucuronidase (GUS) gene was used to transform petunia and transgenic plants were analyzed for GUS activity. GUS staining was localized to mature pollen grains and was not detected in other tissues. Despite similarities to LE-ACS3, we did not detect GUS activity under conditions of anaerobic stress or in response to auxin. A series of 5-prime-flanking DNA deletions revealed that sequences within the PH-ACS2 promoter were responsible for pollen-specific expression.

5

Curran, William S., John M. Wallace, Steven Mirsky, and Benjamin Crockett. "Effectiveness of Herbicides for Control of Hairy Vetch (Vicia villosa) in Winter Wheat." Weed Technology 29, no. 3 (September 2015): 509–18. http://dx.doi.org/10.1614/wt-d-14-00139.1.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

A field experiment was conducted in 2009–2010 at Pennsylvania and Maryland locations, and repeated it in 2010–2011 to test the effectiveness of POST-applied herbicides at fall and spring timings on seeded hairy vetch in winter wheat. A total of 16 herbicide treatment combinations was tested that included synthetic auxins, acetolactate synthase (ALS) inhibitors, and a protoporphyrinogen oxidase inhibitor. Spring applications tended to be more effective than fall applications. Among synthetic auxins, clopyralid (105 g ae ha−1) and treatments containing dicamba (140 g ae ha−1) were effective at both timings, resulting in greater than 90% hairy vetch control at wheat harvest. Pyroxsulam and prosulfuron applied at 18 g ai ha−1 provided the most effective hairy vetch control (> 90%) at both application timings among ALS inhibitors. Spring applications of several herbicides provided moderate (> 80%) to high (> 90%) levels of hairy vetch control, including: 2,4-D amine (140 g ae ha−1), mesosulfuron-methyl (15 g ai ha−1), tribenuron-methyl (13 g ai ha−1), and thifensulfuron/tribenuron-methyl treatments (16 and 32 g ai ha−1). Winter wheat injury was evaluated, but symptoms were negligible for most treatments. Winter wheat yields declined with increasing hairy vetch biomass. Fall herbicides may be prioritized to reduce hairy vetch competition during the fall and early spring growing season. Our research has established that several synthetic auxin and ALS-inhibiting herbicides, applied POST in fall or spring, can be safely used in winter wheat to control hairy vetch in an integrated weed management program.

6

Dominguez-Valenzuela, José Alfredo, Candelario Palma-Bautista, José G. Vazquez-Garcia, Marcos Yanniccari, Ramón Gigón, Ricardo Alcántara-de la Cruz, Rafael De Prado, and João Portugal. "Convergent Adaptation of Multiple Herbicide Resistance to Auxin Mimics and ALS- and EPSPS-Inhibitors in Brassica rapa from North and South America." Plants 12, no. 11 (May 26, 2023): 2119. http://dx.doi.org/10.3390/plants12112119.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Herbicide-resistant weeds have been identified and recorded on every continent where croplands are available. Despite the diversity of weed communities, it is of interest how selection has led to the same consequences in distant regions. Brassica rapa is a widespread naturalized weed that is found throughout temperate North and South America, and it is a frequent weed among winter cereal crops in Argentina and in Mexico. Broadleaf weed control is based on glyphosate that is used prior to sowing and sulfonylureas or mimic auxin herbicides that are used once the weeds have already emerged. This study was aimed at determining whether a convergent phenotypic adaptation to multiple herbicides had occurred in B. rapa populations from Mexico and Argentina by comparing the herbicide sensitivity to inhibitors of the acetolactate synthase (ALS), 5-enolpyruvylshikimate-3-phosphate (EPSPS), and auxin mimics. Five B. rapa populations were analyzed from seeds collected in wheat fields in Argentina (Ar1 and Ar2) and barley fields in Mexico (Mx1, Mx2 and MxS). Mx1, Mx2, and Ar1 populations presented multiple resistance to ALS- and EPSPS-inhibitors and to auxin mimics (2,4-D, MCPA, and fluroxypyr), while the Ar2 population showed resistance only to ALS-inhibitors and glyphosate. Resistance factors ranged from 947 to 4069 for tribenuron-methyl, from 1.5 to 9.4 for 2,4-D, and from 2.7 to 42 for glyphosate. These were consistent with ALS activity, ethylene production, and shikimate accumulation analyses in response to tribenuron-methyl, 2,4-D, and glyphosate, respectively. These results fully support the evolution of the multiple- and cross-herbicide resistance to glyphosate, ALS-inhibitors, and auxinic herbicides in B. rapa populations from Mexico and Argentina.

7

Stankiewicz-Kosyl, Marta, Agnieszka Synowiec, Małgorzata Haliniarz, Anna Wenda-Piesik, Krzysztof Domaradzki, Danuta Parylak, Mariola Wrochna, et al. "Herbicide Resistance and Management Options of Papaver rhoeas L. and Centaurea cyanus L. in Europe: A Review." Agronomy 10, no. 6 (June 18, 2020): 874. http://dx.doi.org/10.3390/agronomy10060874.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Corn poppy (Papaver rhoeas L.) and cornflower (Centaurea cyanus L.) are two overwintering weed species found in crop fields in Europe. They are characterised by a similar life cycle, similar competitive efforts, and a spectrum of herbicides recommended for their control. This review summarises the biology and herbicide resistance phenomena of corn poppy and cornflower in Europe. Corn poppy is one of the most dangerous dicotyledonous weeds, having developed herbicide resistance to acetolactate synthase inhibitors and growth regulators, especially in Mediterranean countries and Great Britain. Target site resistance to acetolactate synthase inhibitors dominates among herbicide-resistant poppy biotypes. The importance of non-target site resistance to acetolactate synthase inhibitors in this species may be underestimated because non-target site resistance is very often associated with target site resistance. Cornflower, meanwhile, is increasingly rare in European agricultural landscapes, with acetolactate synthase inhibitors-resistant biotypes only listed in Poland. However, the mechanisms of cornflower herbicide resistance are not well recognised. Currently, herbicides mainly from acetolactate synthase and photosystem II inhibitors as well as from synthetic auxins groups are recommended for the control of both weeds. Integrated methods of management of both weeds, especially herbicide-resistant biotypes, continue to be underrepresented.

8

Sato, T., and A. Theologis. "Cloning the mRNA encoding 1-aminocyclopropane-1-carboxylate synthase, the key enzyme for ethylene biosynthesis in plants." Proceedings of the National Academy of Sciences 86, no. 17 (September 1989): 6621–25. http://dx.doi.org/10.1073/pnas.86.17.6621.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Ethylene is the plant hormone that controls several features of plant growth and development. The rate-limiting step in its synthesis is the formation of the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC) from S-adenosylmethionine (AdoMet), catalyzed by ACC synthase. We have isolated a complementary DNA sequence encoding ACC synthase from zucchini (Cucurbita) fruits. The biological activity of the clone was confirmed by the ability of the cloned sequence to direct ACC synthase activity in Escherichia coli and yeast. In vivo studies using the ACC cDNA as probe showed that the ACC synthase gene is induced by a diverse group of inducers, including wounding, Li+ ions, and the plant hormone auxin.

9

Preston, Christopher, Fleur C. Dolman, and Peter Boutsalis. "Multiple Resistance to Acetohydroxyacid Synthase–Inhibiting and Auxinic Herbicides in a Population of Oriental Mustard (Sisymbrium orientale)." Weed Science 61, no. 2 (June 2013): 185–92. http://dx.doi.org/10.1614/ws-d-12-00117.1.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

A population of oriental mustard from Port Broughton in South Australia was reported as not being controlled by 2,4-D. Dose response experiments determined this population was resistant to both 2,4-D and MCPA, requiring greater than 20 times more herbicide for equivalent control compared to a known susceptible population (from Roseworthy, South Australia) and a population resistant only to the acetohydroxyacid synthase (AHAS)-inhibiting herbicides (from Tumby Bay, South Australia). The Port Broughton population was also found to be resistant to three chemical groups that inhibit AHAS; however, the level of resistance was lower than the known acetolactate synthase–resistant population from Tumby Bay. Herbicides from other modes of action were able to control the Port Broughton population. Assays of isolated AHAS from the Port Broughton population showed high levels of resistance to the sulfonylurea and sulfonamide herbicide groups, but not to the imidazolinone herbicides. A single nucleotide change in the AHAS gene that predicted a Pro to Ser substitution at position 197 in the protein was identified in the Port Broughton population. This population of oriental mustard has evolved multiple resistance to AHAS-inhibiting herbicides (AHAS inhibitors) and auxinic herbicides, through a mutation in AHAS and a second nontarget-site mechanism. Whether the same mechanism provides resistance to both AHAS inhibitors and auxinic herbicides remains to be determined. Multiple resistance to auxinic herbicides and AHAS inhibitors in the Port Broughton population will make control of this population more difficult.

10

Wang, Bing, Jinfang Chu, Tianying Yu, Qian Xu, Xiaohong Sun, Jia Yuan, Guosheng Xiong, Guodong Wang, Yonghong Wang, and Jiayang Li. "Tryptophan-independent auxin biosynthesis contributes to early embryogenesis in Arabidopsis." Proceedings of the National Academy of Sciences 112, no. 15 (March 23, 2015): 4821–26. http://dx.doi.org/10.1073/pnas.1503998112.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

The phytohormone auxin regulates nearly all aspects of plant growth and development. Tremendous achievements have been made in elucidating the tryptophan (Trp)-dependent auxin biosynthetic pathway; however, the genetic evidence, key components, and functions of the Trp-independent pathway remain elusive. Here we report that the Arabidopsis indole synthase mutant is defective in the long-anticipated Trp-independent auxin biosynthetic pathway and that auxin synthesized through this spatially and temporally regulated pathway contributes significantly to the establishment of the apical–basal axis, which profoundly affects the early embryogenesis in Arabidopsis. These discoveries pave an avenue for elucidating the Trp-independent auxin biosynthetic pathway and its functions in regulating plant growth and development.

11

Torbiak, Alysha T., Robert E. Blackshaw, Randall N. Brandt, Bill Hamman, and Charles M. Geddes. "Herbicide strategies for managing glyphosate-resistant and -susceptible kochia (Bassia scoparia) in spring wheat." Canadian Journal of Plant Science 101, no. 4 (August 1, 2021): 607–21. http://dx.doi.org/10.1139/cjps-2020-0303.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Kochia [Bassia scoparia (L.) A.J. Scott] is a summer annual tumbleweed that is tolerant of heat, drought, and salinity and capable of causing large yield losses in spring wheat (Triticum aestivum L). Increased incidence of glyphosate- and acetolactate synthase (ALS) inhibitor-resistant kochia in western Canada warrants investigation of alternative herbicides to manage these biotypes. Herbicides applied pre- or post-emergence in spring wheat were evaluated based on crop tolerance and control of ALS inhibitor-resistant kochia accessions with and without the glyphosate resistance trait in five environments near Lethbridge and Coalhurst, Alberta, from 2013 to 2015. The most effective and consistent treatments for kochia management included sulfentrazone applied pre-emergence and fluroxypyr/bromoxynil/2,4-D or pyrasulfotole/bromoxynil applied post-emergence. All of these treatments resulted in ≥90% visible control in all environments and ≥90% kochia biomass reduction compared with the untreated control in Lethbridge 2014 and 2015. MCPA/dichlorprop-p/mecoprop-p, dicamba/2,4-D/mecoprop-p, and dicamba/fluroxypyr resulted in acceptable control among environments (≥80% visible control in all environments and ≥80% kochia biomass reduction in Lethbridge 2014 and 2015); however, the latter two options caused unacceptable (>10%) wheat visible injury in Coalhurst 2014. Recent confirmations of auxinic herbicide-resistant kochia in western Canada—due, in part, to use of synthetic auxins to manage glyphosate-resistant kochia in small-grain cereals—will limit kochia management options. When implemented with non-chemical tools as part of an integrated weed management program, alternative herbicide modes of action like protoporphyrinogen oxidase inhibitors before and photosystem II or 4-hydroxyphenylpyruvate dioxygenase inhibitor(s) within spring wheat could mitigate selection for multiple herbicide-resistant kochia.

12

Lugassi, Nitsan, Ofer Stein, Aiman Egbaria, Eduard Belausov, Hanita Zemach, Tal Arad, David Granot, and Nir Carmi. "Sucrose Synthase and Fructokinase Are Required for Proper Meristematic and Vascular Development." Plants 11, no. 8 (April 11, 2022): 1035. http://dx.doi.org/10.3390/plants11081035.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Sucrose synthase (SuSy) and fructokinase (FRK) work together to control carbohydrate flux in sink tissues. SuSy cleaves sucrose into fructose and UDP-glucose; whereas FRK phosphorylates fructose. Previous results have shown that suppression of the SUS1,3&4 genes by SUS-RNAi alters auxin transport in the shoot apical meristems of tomato plants and affects cotyledons and leaf structure; whereas antisense suppression of FRK2 affects vascular development. To explore the joint developmental roles of SuSy and FRK, we crossed SUS-RNAi plants with FRK2-antisense plants to create double-mutant plants. The double-mutant plants exhibited novel phenotypes that were absent from the parent lines. About a third of the plants showed arrested shoot apical meristem around the transition to flowering and developed ectopic meristems. Use of the auxin reporter DR5::VENUS revealed a significantly reduced auxin response in the shoot apical meristems of the double-mutant, indicating that auxin levels were low. Altered inflorescence phyllotaxis and significant disorientation of vascular tissues were also observed. In addition, the fruits and the seeds of the double-mutant plants were very small and the seeds had very low germination rates. These results show that SUS1,3&4 and FRK2 enzymes are jointly essential for proper meristematic and vascular development, and for fruit and seed development.

13

Liao, Pan, Shiu-Cheung Lung, Wai Lung Chan, Thomas J. Bach, Clive Lo, and Mee-Len Chye. "Overexpression of HMG-CoA synthase promotes Arabidopsis root growth and adversely affects glucosinolate biosynthesis." Journal of Experimental Botany 71, no. 1 (September 26, 2019): 272–89. http://dx.doi.org/10.1093/jxb/erz420.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Inhibition of 3-hydroxy-3-methylglutaryl-CoA synthase (HMGS) retarded root growth in Arabidopsis seedlings by reducing stigmasterol, auxin, and cytokinin levels. Differentially expressed proteins and metabolite changes revealed a relationship between HMGS and glucosinolate biosynthesis.

14

Lehman, Thiel A., and Karen A. Sanguinet. "Auxin and Cell Wall Crosstalk as Revealed by the Arabidopsis thaliana Cellulose Synthase Mutant Radially Swollen 1." Plant and Cell Physiology 60, no. 7 (April 20, 2019): 1487–503. http://dx.doi.org/10.1093/pcp/pcz055.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

AbstractPlant cells sheath themselves in a complex lattice of polysaccharides, proteins and enzymes forming an integral matrix known as the cell wall. Cellulose microfibrils, the primary component of cell walls, are synthesized at the plasma membrane by CELLULOSE SYNTHASE A (CESA) proteins throughout cellular growth and are responsible for turgor-driven anisotropic expansion. Associations between hormone signaling and cell wall biosynthesis have long been suggested, but recently direct links have been found revealing hormones play key regulatory roles in cellulose biosynthesis. The radially swollen 1 (rsw1) allele of Arabidopsis thaliana CESA1 harbors a single amino acid change that renders the protein unstable at high temperatures. We used the conditional nature of rsw1 to investigate how auxin contributes to isotropic growth. We found that exogenous auxin treatment reduces isotropic swelling in rsw1 roots at the restrictive temperature of 30ï¿½C. We also discovered decreases in auxin influx between rsw1 and wild-type roots via confocal imaging of AUX1-YFP, even at the permissive temperature of 19ï¿½C. Moreover, rsw1 displayed mis-expression of auxin-responsive and CESA genes. Additionally, we found altered auxin maxima in rsw1 mutant roots at the onset of swelling using DII-VENUS and DR5:vYFP auxin reporters. Overall, we conclude disrupted cell wall biosynthesis perturbs auxin transport leading to altered auxin homeostasis impacting both anisotropic and isotropic growth that affects overall root morphology.

15

Ciarkowska, Anna, Maciej Ostrowski, and Anna Kozakiewicz. "Biochemical Characterization of Recombinant UDPG-Dependent IAA Glucosyltransferase from Maize (Zea mays)." International Journal of Molecular Sciences 22, no. 7 (March 25, 2021): 3355. http://dx.doi.org/10.3390/ijms22073355.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Here, we report a biochemical characterization of recombinant maize indole-3-acetyl-β-d-glucose (IAGlc) synthase which glucosylates indole-3-acetic acid (IAA) and thus abolishes its auxinic activity affecting plant hormonal homeostasis. Substrate specificity analysis revealed that IAA is a preferred substrate of IAGlc synthase; however, the enzyme can also glucosylate indole-3-butyric acid and indole-3-propionic acid with the relative activity of 66% and 49.7%, respectively. KM values determined for IAA and UDP glucose are 0.8 and 0.7 mM, respectively. 2,4-Dichlorophenoxyacetic acid is a competitive inhibitor of the synthase and causes a 1.5-fold decrease in the enzyme affinity towards IAA, with the Ki value determined as 117 μM, while IAA–Asp acts as an activator of the synthase. Two sugar-phosphate compounds, ATP and glucose-1-phosphate, have a unique effect on the enzyme by acting as activators at low concentrations and showing inhibitory effect at higher concentrations (above 0.6 and 4 mM for ATP and glucose-1-phosphate, respectively). Results of molecular docking revealed that both compounds can bind to the PSPG (plant secondary product glycosyltransferase) motif of IAGlc synthase; however, there are also different potential binding sites present in the enzyme. We postulate that IAGlc synthase may contain more than one binding site for ATP and glucose-1-phosphate as reflected in its activity modulation.

16

An, Gynheung, Michael A. Costa, and Sam-Bong Ha. "Nopaline Synthase Promoter Is Wound Inducible and Auxin Inducible." Plant Cell 2, no. 3 (March 1990): 225. http://dx.doi.org/10.2307/3869137.

Full text

APA, Harvard, Vancouver, ISO, and other styles

17

An, G., M. A. Costa, and S. B. Ha. "Nopaline synthase promoter is wound inducible and auxin inducible." Plant Cell 2, no. 3 (March 1990): 225–33. http://dx.doi.org/10.1105/tpc.2.3.225.

Full text

APA, Harvard, Vancouver, ISO, and other styles

18

Pierdonati, Emanuela, Simon Josef Unterholzner, Elena Salvi, Noemi Svolacchia, Gaia Bertolotti, Raffaele Dello Ioio, Sabrina Sabatini, and Riccardo Di Mambro. "Cytokinin-Dependent Control of GH3 Group II Family Genes in the Arabidopsis Root." Plants 8, no. 4 (April 8, 2019): 94. http://dx.doi.org/10.3390/plants8040094.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Abstract: The Arabidopsis root is a dynamic system where the interaction between different plant hormones controls root meristem activity and, thus, organ growth. In the root, a characteristic graded distribution of the hormone auxin provides positional information, coordinating the proliferating and differentiating cell status. The hormone cytokinin shapes this gradient by positioning an auxin minimum in the last meristematic cells. This auxin minimum triggers a cell developmental switch necessary to start the differentiation program, thus, regulating the root meristem size. To position the auxin minimum, cytokinin promotes the expression of the IAA-amido synthase group II gene GH3.17, which conjugates auxin with amino acids, in the most external layer of the root, the lateral root cap tissue. Since additional GH3 genes are expressed in the root, we questioned whether cytokinin to position the auxin minimum also operates via different GH3 genes. Here, we show that cytokinin regulates meristem size by activating the expression of GH3.5 and GH3.6 genes, in addition to GH3.17. Thus, cytokinin activity provides a robust control of auxin activity in the entire organ necessary to regulate root growth.

19

Ray, Peter M. "Auxin and Fusicoccin Enhancement of β-Glucan Synthase in Peas." Plant Physiology 78, no. 3 (July 1, 1985): 466–72. http://dx.doi.org/10.1104/pp.78.3.466.

Full text

APA, Harvard, Vancouver, ISO, and other styles

20

Du, Xin-Qiao, Hong-Yan Yao, Pan Luo, Xing-Chun Tang, and Hong-Wei Xue. "Cytidinediphosphate diacylglycerol synthase—Mediated phosphatidic acid metabolism is crucial for early embryonic development of Arabidopsis." PLOS Genetics 18, no. 7 (July 25, 2022): e1010320. http://dx.doi.org/10.1371/journal.pgen.1010320.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Embryonic development is a key developmental event in plant sexual reproduction; however, regulatory networks of plant early embryonic development, particularly the effects and functional mechanisms of phospholipid molecules are still unknown due to the limitation of sample collection and analysis. We innovatively applied the microspore-derived in vitro embryogenesis of Brassica napus and revealed the dynamics of phospholipid molecules, especially phosphatidic acid (PA, an important second messenger that plays an important role in plant growth, development, and stress responses), at different embryonic developmental stages by using a lipidomics approach. Further analysis of Arabidopsis mutants deficiency of CDS1 and CDS2 (cytidinediphosphate diacylglycerol synthase, key protein in PA metabolism) revealed the delayed embryonic development from the proembryo stage, indicating the crucial effect of CDS and PA metabolism in early embryonic development. Decreased auxin level and disturbed polar localization of auxin efflux carrier PIN1 implicate that CDS-mediated PA metabolism may regulate early embryogenesis through modulating auxin transport and distribution. These results demonstrate the dynamics and importance of phospholipid molecules during embryo development, and provide informative clues to elucidate the regulatory network of embryogenesis.

21

Hutangura, Pokkwan, Ulrike Mathesius, Mike G. K. Jones, and Barry G. Rolfe. "Auxin induction is a trigger for root gall formation caused by root-knot nematodes in white clover and is associated with the activation of the flavonoid pathway." Functional Plant Biology 26, no. 3 (1999): 221. http://dx.doi.org/10.1071/pp98157.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

We studied the expression of the auxin responsive promoter (GH3) fused to the gusA reporter gene in white clover (Trifolium repens cv. Haifa) during the initiation of root galls by root-knot nematodes (Meloidogyne javanica) to investigate whether nematode infection affects auxin distribution in developing galls. In search for a plant signal that would mediate changes in auxin location we studied the induction of the flavonoid pathway because flavonoids can act as auxin transport regulators. Three chalcone synthase (CHS1, CHS2 and CHS3) promoter:gusA fusions were examined in transgenic plants and flavonoids were detected using fluorescence microscopy. Within 24 h post inoculation CHS:gusA expression occurred around the invading nematode. At 48 h post inoculation CHS:gusA expression and flavonoids were detected throughout the infection site, followed by high GH3:gusA expression in the gall 48–72 h post inoculation. Initially (48–72 h post inoculation) high GH3:gusA expression in giant cell precursors was followed by low expression in the enlarging giant cells (96–120 h post inoculation), suggesting that auxin is needed as a trigger for giant cell initiation but not for later enlargement. We suggest that nematodes control auxin distribution in the root and that flavonoids could be responsible for controlling auxin accumulation.

22

Beckie, Hugh J., Linda M. Hall, Scott W. Shirriff, Elise Martin, and Julia Y. Leeson. "Triple-resistant kochia [Kochia scoparia (L.) Schrad.] in Alberta." Canadian Journal of Plant Science 99, no. 2 (April 1, 2019): 281–85. http://dx.doi.org/10.1139/cjps-2018-0256.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

A randomized stratified survey was conducted in Alberta in 2017 to determine the distribution and abundance of multiple-resistant [acetolactate synthase (ALS) inhibitor, glycine, and synthetic auxin] kochia. All populations were ALS inhibitor resistant, with glyphosate and dicamba resistance confirmed in 50% and 18% of populations, respectively. Ten percent of populations exhibited resistance to all three mode-of-action herbicides.

23

Péron, Thomas, Christophe Véronési, Eric Mortreau, Jean-Bernard Pouvreau, Séverine Thoiron, Nathalie Leduc, Philippe Delavault, and Philippe Simier. "Role of the Sucrose Synthase Encoding PrSus1 Gene in the Development of the Parasitic Plant Phelipanche ramosa L. (Pomel)." Molecular Plant-Microbe Interactions® 25, no. 3 (March 2012): 402–11. http://dx.doi.org/10.1094/mpmi-10-11-0260.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Phelipanche ramosa L. (Pomel) is a major root-parasitic weed attacking many important crops. Success in controlling this parasite is rare and a better understanding of its unique biology is needed to develop new specific control strategies. In the present study, quantitative polymerase chain reaction experiments showed that sucrose synthase encoding PrSus1 transcripts accumulate at their highest level once the parasite is connected to the host (tomato) vascular system, mainly in the parasite tubercles, which bear numerous adventitious roots. In situ hybridization experiments revealed strong PrSus1 expression in both shoot and root apices, especially in shoot apical meristems and in the vascular tissues of scale leaves and stems, and in the apical meristems and developing xylem in roots. In addition, immunolocalization experiments showed that a sucrose synthase protein co-localized with cell-wall thickening in xylem elements. These findings highlight the role of PrSus1 in the utilization of host-derived sucrose in meristematic areas and in cellulose biosynthesis in differentiating vascular elements. We also demonstrate that PrSus1 is downregulated in response to 2,3,5-triiodobenzoic acid-induced inhibition of polar auxin transport in the host stem, suggesting that PrSus1 activity in xylem maturation is controlled by host-derived auxin.

24

Dzhamieiev, V. Y. "Modern concepts of auxin’s action. 1. History of discovery, metabolism, transport." Vìsnik Harkìvsʹkogo nacìonalʹnogo agrarnogo unìversitetu. Serìâ Bìologiâ 2020, no. 3 (October 30, 2020): 98–123. http://dx.doi.org/10.35550/vbio2020.03.098.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Auxin (indolyl-3-acetic acid, IAA) is one of the key classical phytohormones with a very wide range of physiological effects. The first part of the scientific lecture describes the main stages of discovery of the hormone. The main pathways of auxin synthesis in plant tissues, which is carried out in two different ways: tryptophan-dependent and tryptophan-independent, are considered in detail. At the same time, multiple pathways of the auxin formation from tryptophan have been found in plant tissues. Among them, the mechanisms that occur with the formation of such intermediate metabolites as indole-3-acetaldoxime, indole-3-pyruvate and indole-3-acetamide are considered. The indole-3-pyruvate pathway is currently considered the main mechanism of hormone synthesis. Experimental evidence has also been obtained for the functioning of the tryptophan-independent pathway of auxin synthesis, the key enzyme of which is cytoplasmic indole synthase. It is assumed that the precursor of auxin in the tryptophan-independent pathway may be some intermediate metabolite between anthranilic acid and tryptophan. The article also describes the routes of auxin inactivation through the formation of conjugated forms and oxidation. A brief characterization of IAA dioxygenases, belonging to the 2-oxoglutarate-Fe (II)-oxygenases family, which are currently considered the main catalytic systems for auxin oxidation, is presented. The mechanisms and significance of polar and lateral transport of auxin are discussed. The characteristics of transmembrane auxin transporters belonging to the families PIN/PIL, ABCB/PGP and AUX/LAX are given.

25

Uddin, Saleem, Muhammad Zeeshan Munir, Sadia Gull, Aamir Hamid Khan, Aimal Khan, Dilawar Khan, Muhammad Asif Khan, Yue Wu, Yuhan Sun, and Yun Li. "Transcriptome Profiling Reveals Role of MicroRNAs and Their Targeted Genes during Adventitious Root Formation in Dark-Pretreated Micro-Shoot Cuttings of Tetraploid Robinia pseudoacacia L." Genes 13, no. 3 (February 27, 2022): 441. http://dx.doi.org/10.3390/genes13030441.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Tetraploid Robinia pseudoacacia L. is a difficult-to-root species, and is vegetatively propagated through stem cuttings. Limited information is available regarding the adventitious root (AR) formation of dark-pretreated micro-shoot cuttings. Moreover, the role of specific miRNAs and their targeted genes during dark-pretreated AR formation under in vitro conditions has never been revealed. The dark pretreatment has successfully promoted and stimulated adventitious rooting signaling-related genes in tissue-cultured stem cuttings with the application of auxin (0.2 mg L−1 IBA). Histological analysis was performed for AR formation at 0, 12, 36, 48, and 72 h after excision (HAE) of the cuttings. The first histological events were observed at 36 HAE in the dark-pretreated cuttings; however, no cellular activities were observed in the control cuttings. In addition, the present study aimed to uncover the role of differentially expressed (DE) microRNAs (miRNAs) and their targeted genes during adventitious root formation using the lower portion (1–1.5 cm) of tetraploid R. pseudoacacia L. micro-shoot cuttings. The samples were analyzed using Illumina high-throughput sequencing technology for the identification of miRNAs at the mentioned time points. Seven DE miRNA libraries were constructed and sequenced. The DE number of 81, 162, 153, 154, 41, 9, and 77 miRNAs were upregulated, whereas 67, 98, 84, 116, 19, 16, and 93 miRNAs were downregulated in the following comparisons of the libraries: 0-vs-12, 0-vs-36, 0-vs-48, 0-vs-72, 12-vs-36, 36-vs-48, and 48-vs-72, respectively. Furthermore, we depicted an association between ten miRNAs (novel-m0778-3p, miR6135e.2-5p, miR477-3p, miR4416c-5p, miR946d, miR398b, miR389a-3p, novel m0068-5p, novel-m0650-3p, and novel-m0560-3p) and important target genes (auxin response factor-3, gretchen hagen-9, scarecrow-like-1, squamosa promoter-binding protein-like-12, small auxin upregulated RNA-70, binding protein-9, vacuolar invertase-1, starch synthase-3, sucrose synthase-3, probable starch synthase-3, cell wall invertase-4, and trehalose phosphatase synthase-5), all of which play a role in plant hormone signaling and starch and sucrose metabolism pathways. The quantitative polymerase chain reaction (qRT-PCR) was used to validate the relative expression of these miRNAs and their targeted genes. These results provide novel insights and a foundation for further studies to elucidate the molecular factors and processes controlling AR formation in woody plants.

26

Mathesius, Ulrike, Celine Charon, Barry G. Rolfe, Adam Kondorosi, and Martin Crespi. "Temporal and Spatial Order of Events During the Induction of Cortical Cell Divisions in White Clover by Rhizobium leguminosarum bv. trifolii Inoculation or Localized Cytokinin Addition." Molecular Plant-Microbe Interactions® 13, no. 6 (June 2000): 617–28. http://dx.doi.org/10.1094/mpmi.2000.13.6.617.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

We examined the timing and location of several early root responses to Rhizobium leguminosarum bv. trifolii infection, compared with a localized addition of cytokinin in white clover, to study the role of cytokinin in early signaling during nodule initiation. Induction of ENOD40 expression by either rhizobia or cytokinin was similar in timing and location and occurred in nodule progenitor cells in the inner cortex. Inoculation of rhizobia in the mature root failed to induce ENOD40 expression and cortical cell divisions (ccd). Nitrate addition at levels repressing nodule formation inhibited ENOD40 induction by rhizobia but not by cytokinin. ENOD40 expression was not induced by auxin, an auxin transport inhibitor, or an ethylene precursor. In contrast to rhizobia, cytokinin addition was not sufficient to induce a modulation of the auxin flow, the induction of specific chalcone synthase genes, and the accumulation of fluorescent compounds associated with nodule initiation. However, cytokinin addition was sufficient for the localized induction of auxin-induced GH3 gene expression and the initiation of ccd. Our results suggest that rhizobia induce cytokinin-mediated events in parallel to changes in auxin-related responses during nodule initiation and support a role of ENOD40 in regulating ccd. We propose a model for the interactions of cytokinin with auxin, ENOD40, flavonoids, and nitrate during nodulation.

27

Stankiewicz-Kosyl, Marta, Małgorzata Haliniarz, Mariola Wrochna, Agnieszka Synowiec, Anna Wenda-Piesik, Ewa Tendziagolska, Magdalena Sobolewska, et al. "Herbicide Resistance of Centaurea cyanus L. in Poland in the Context of Its Management." Agronomy 11, no. 10 (September 28, 2021): 1954. http://dx.doi.org/10.3390/agronomy11101954.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Cornflower (Centaurea cyanus L.), one of the main weeds found among winter crops in Poland, has developed herbicide resistance (HR) to acetolactate synthase (ALS) herbicides, a finding first reported in 2006, and in recent years, farmers have been complaining about inadequate chemical control of this weed. This study aimed to characterise the current state of cornflower HR to ALS inhibitors and synthetic auxins in Poland and the agricultural practices in fields with herbicide-resistant populations. From 2017 to 2020, 159 seed samples together with the field history were collected across the country and biological tests performed in glasshouses. This revealed that 47 populations of C. cyanus were cross-resistant to both tribenuron and florasulam, 28 and 8 populations were single resistant to tribenuron and florasulam, respectively, and 3 populations had developed multiple resistance to both ALS inhibitors and synthetic auxins, i.e., 2,4-D and dicamba. Resistant populations were found mostly frequent in northern Poland, but also in the eastern and western parts of the country. Based on a survey of farmers, the resistant populations were found in winter crops regardless of the tillage system (77% of fields with HR cornflower were mouldboard ploughed). Based on the proposed population treatment (PT) index showing the frequency of herbicide use during three consecutive seasons on farms with HR cornflower, the average PT for all the surveyed farms was 5.4. The highest PT of 7.4 was found in the province of Warmia-Masuria in northern Poland.

28

Xiong, Chuanyong, Xiaoqing Li, Xin Wang, Jingxin Wang, Hans Lambers, Carroll P. Vance, Jianbo Shen, and Lingyun Cheng. "Flavonoids are involved in phosphorus-deficiency-induced cluster-root formation in white lupin." Annals of Botany 129, no. 1 (October 20, 2021): 101–12. http://dx.doi.org/10.1093/aob/mcab131.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Abstract Background and Aims Initiation of cluster roots in white lupin (Lupinus albus) under phosphorus (P) deficiency requires auxin signalling, whereas flavonoids inhibit auxin transport. However, little information is available about the interactions between P deficiency and flavonoids in terms of cluster-root formation in white lupin. Methods Hydroponic and aeroponic systems were used to investigate the role of flavonoids in cluster-root formation, with or without 75 μm P supply. Key Results Phosphorus-deficiency-induced flavonoid accumulation in cluster roots depended on developmental stage, based on in situ determination of fluorescence of flavonoids and flavonoid concentration. LaCHS8, which codes for a chalcone synthase isoform, was highly expressed in cluster roots, and silencing LaCHS8 reduced flavonoid production and rootlet density. Exogenous flavonoids suppressed cluster-root formation. Tissue-specific distribution of flavonoids in roots was altered by P deficiency, suggesting that P deficiency induced flavonoid accumulation, thus fine-tuning the effect of flavonoids on cluster-root formation. Furthermore, naringenin inhibited expression of an auxin-responsive DR5:GUS marker, suggesting an interaction of flavonoids and auxin in regulating cluster-root formation. Conclusions Phosphorus deficiency triggered cluster-root formation through the regulation of flavonoid distribution, which fine-tuned an auxin response in the early stages of cluster-root development. These findings provide valuable insights into the mechanisms of cluster-root formation under P deficiency.

29

Goren, Shlomo, Nitsan Lugassi, Ofer Stein, Yelena Yeselson, Arthur A. Schaffer, Rakefet David-Schwartz, and David Granot. "Suppression of sucrose synthase affects auxin signaling and leaf morphology in tomato." PLOS ONE 12, no. 8 (August 7, 2017): e0182334. http://dx.doi.org/10.1371/journal.pone.0182334.

Full text

APA, Harvard, Vancouver, ISO, and other styles

30

Matzrafi, Maor, Ofri Gerson, Moshe Sibony, and Baruch Rubin. "Target Site Resistance to Acetolactate Synthase Inhibitors in Diplotaxis erucoides and Erucaria hispanica–Mechanism of Resistance and Response to Alternative Herbicides." Agronomy 10, no. 4 (March 29, 2020): 471. http://dx.doi.org/10.3390/agronomy10040471.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Diplotaxis erucoides and Erucaria hispanica are common weeds of the Mediterranean region; they infest various habitats including cultivated fields and roadsides. In several fields across Israel, farmers have reported on poor control of D. erucoides and E. hispanica plants using acetolactate synthase (ALS) inhibitors. Greenhouse experiments were conducted to determine the effect of various ALS inhibitors on plants from two potentially resistant D. erucoides and E. hispanica populations. Additionally, alternative management strategies using auxinic herbicides were studied. Plants from both populations exhibited resistance to all tested ALS inhibitors, up to 20-fold the label field rate, as compared with ALS sensitive populations of D. erucoides and E. hispanica. Sequencing of the ALS gene revealed Trp574 to Leu substitution in ALS-resistant D. erucoides plants, whereas a Pro197 to Ser substitution was detected in ALS-resistant E. hispanica plants. Although high levels of resistance were observed in individuals from both putative resistant populations, sensitive individuals were also detected, suggesting the evolution of resistance in these two populations is still in progress. Auxinic herbicides, 2,4-D, and mecoprop-P, provided excellent control of plants from both ALS-resistant populations. This study documents and confirms the first case of evolution of resistance to ALS inhibitors in D. erucoides and E. hispanica populations.

31

Pollmann, S., A. Müller, and E. W. Weiler. "Many Roads Lead to "Auxin": of Nitrilases, Synthases, and Amidases." Plant Biology 8, no. 3 (May 2006): 326–33. http://dx.doi.org/10.1055/s-2006-924075.

Full text

APA, Harvard, Vancouver, ISO, and other styles

32

Diez Vignola, Manuel, Martha Sainz, Néstor E. Saldain, Claudia Marchesi, Victoria Bonnecarrère, and Pedro Díaz Gadea. "Limited induction of ethylene and cyanide synthesis are observed in quinclorac-resistant barnyardgrass (Echinochloa crus-galli) in Uruguay." Weed Science 68, no. 4 (April 28, 2020): 348–57. http://dx.doi.org/10.1017/wsc.2020.32.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

AbstractBarnyardgrass [Echinochloa crus-galli (L.) P. Beauv] is the foremost weed in rice (Oryza sativa L.) systems, and its control is crucial to successful rice production. Quinclorac, a synthetic auxin herbicide, has been used effectively to manage E. crus-galli. However, occurrences of quinclorac-resistant genotypes are frequently reported, and its resistance evolution has led to questions about the continued utility of quinclorac for grass control. Identification of the resistance mechanism(s) of resistant genotypes will facilitate development of integrated weed management strategies that sustain quinclorac use for management of E. crus-galli. We evaluated the responses to quinclorac of two contrasting genotypes: E7 (resistant, R) and LM04 (susceptible, S). Quinclorac induced ethylene and cyanide biosynthesis in the S-genotype. Both genotypes responded similarly to an increasing application of exogenous 1-carboxylic acid aminocyclopropane (ACC) and potassium cyanide, and their growth was inhibited at higher doses. The key mechanism for cyanide (HCN) detoxification in plants, β-cyanoalanine synthase (β-CAS) activity, was evaluated in both genotypes, and no significant difference was observed in the basal activity. However, quinclorac significantly induced β-CAS–like activity in the S-genotype, which is consistent with the increased synthesis of ethylene and cyanide. This work suggests that the resistance to quinclorac of the E7 R-genotype is likely related to an alteration in the auxin signal transduction pathway, causing a lower stimulation of ACC synthase and, therefore, limited synthesis of ethylene and HCN after quinclorac treatment.

33

Oliva-Hernández, Amanda Alejandra, Jesús Di Carlo Quiroz-Velásquez, Jesus Gerardo García-Olivares, Israel García-León, Cristian Lizarazo-Ortega, and Jose Luis Hernández-Mendoza. "Detection of auxinic compounds in germinating seedlings." Revista de Ciencias Agrícolas 38, no. 2 (September 29, 2021): 63–74. http://dx.doi.org/10.22267/rcia.213802.162.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Tryptophan (TRP) is a metabolite from which several important metabolic syntheses arise in plants, animals, and humans. In bacteria and fungi, it is a precursor of Indole Acetic acid (IAA) using various metabolic pathways. The objective of this study is the detection of intermediate metabolites in the synthesis of IAA in seeds of several species in the germination process. In the study, seeds of plant species grown in deionized water were placed in order to stimulate germination and samples were taken every 24 hours. High performance liquid chromatography (HPLC) was used for the detection of the compounds. The results show that the pH of the medium is altered and there is no pattern of behavior. Regarding the detected compounds, in addition to TRP, there is indole-3-acetamide (IAM), 3-indoleacetonitrile (IAN), tryptamine (TRM), which are part of the TRP-dependent routes, since they use this amino acid as a precursor. Anthranilic acid (AA) and kynurenine (KYN), which are part of the Independent TRP pathway, were also detected. IAA and TRP were also detected during the germination process of the studied seeds (Sorghum bicolor, T aesativum, Zea mayz, Phaseolus vulgaris, G. hirsutum, Cucurbita maxima). Finally, it was observed that the seeds, due to weight loss, suffer physical wear during the germination process, since there is a difference between the initial dry weight and the weight of the seeds at the end of the study.

34

Silva, Saúl, Osvaldo S. Ascenso, Eva C. Lourenço, Margarida Archer, Christopher D. Maycock, and M. Rita Ventura. "Syntheses of the plant auxin conjugate 2-O-(indole-3-acetyl)-myo-inositol IAInos." Organic & Biomolecular Chemistry 16, no. 38 (2018): 6860–64. http://dx.doi.org/10.1039/c8ob02096e.

Full text

APA, Harvard, Vancouver, ISO, and other styles

35

Xin, Xiaoran, Lei Lei, Yunzhen Zheng, Tian Zhang, Sai Venkatesh Pingali, Hugh O’Neill, Daniel J. Cosgrove, Shundai Li, and Ying Gu. "Cellulose synthase interactive1- and microtubule-dependent cell wall architecture is required for acid growth in Arabidopsis hypocotyls." Journal of Experimental Botany 71, no. 10 (February 4, 2020): 2982–94. http://dx.doi.org/10.1093/jxb/eraa063.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Abstract Auxin-induced cell elongation relies in part on the acidification of the cell wall, a process known as acid growth that presumably triggers expansin-mediated wall loosening via altered interactions between cellulose microfibrils. Cellulose microfibrils are a major determinant for anisotropic growth and they provide the scaffold for cell wall assembly. Little is known about how acid growth depends on cell wall architecture. To explore the relationship between acid growth-mediated cell elongation and plant cell wall architecture, two mutants (jia1-1 and csi1-3) that are defective in cellulose biosynthesis and cellulose microfibril organization were analyzed. The study revealed that cell elongation is dependent on CSI1-mediated cell wall architecture but not on the overall crystalline cellulose content. We observed a correlation between loss of crossed-polylamellate walls and loss of auxin- and fusicoccin-induced cell growth in csi1-3. Furthermore, induced loss of crossed-polylamellate walls via disruption of cortical microtubules mimics the effect of csi1 in acid growth. We hypothesize that CSI1- and microtubule-dependent crossed-polylamellate walls are required for acid growth in Arabidopsis hypocotyls.

36

Walsh, Michael J., Stephen B. Powles, Brett R. Beard, Ben T. Parkin, and Sally A. Porter. "Multiple-herbicide resistance across four modes of action in wild radish (Raphanus raphanistrum)." Weed Science 52, no. 1 (February 2004): 8–13. http://dx.doi.org/10.1614/ws-03-016r.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Populations of wild radish were collected from two fields in the northern Western Australian wheatbelt, where typical herbicide-use patterns had been practiced for the previous 17 seasons within an intensive crop production program. The herbicide resistance status of these populations clearly established that there was multiple-herbicide resistance across many herbicides from at least four modes of action. One population exhibited multiple-herbicide resistance to the phytoene desaturase (PDS)–inhibiting herbicide diflufenican (3.0-fold), the auxin analog herbicide 2,4-D (2.2-fold), and the photosystem II–inhibiting herbicides metribuzin and atrazine. Another population was found to be multiply resistant to the acetolactate synthase–inhibiting herbicides, the PDS-inhibiting herbicide diflufenican (2.5-fold), and the auxin analog herbicide 2,4-D amine (2.4-fold). Therefore, each population has developed multiple-herbicide resistance across several modes of action. The multiple resistance status of these wild radish populations developed from conventional herbicide usage in intensive cropping rotations, indicating a dramatic challenge for the future control of wild radish.

37

Lahey, Katherine A., Rongcai Yuan, Jacqueline K. Burns, Peter P. Ueng, L. W. Timmer, and Kuang-Ren Chung. "Induction of Phytohormones and Differential Gene Expression in Citrus Flowers Infected by the Fungus Colletotrichum acutatum." Molecular Plant-Microbe Interactions® 17, no. 12 (December 2004): 1394–401. http://dx.doi.org/10.1094/mpmi.2004.17.12.1394.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Colletotrichum acutatum infects citrus petals and induces premature fruit drop and the formation of persistent calyces. The accumulation of hormones and other growth regulators, and differential gene expression in affected flowers and young fruit, was examined following fungal infection. Ethylene evolution increased threefold and indole-3-acetic acid (IAA) accumulation was as much as 140 times. Abscisic acid (ABA) levels showed no significant response. After infection, both trans- and cis-12-oxo-phytodienoic acid increased 8- to 10-fold. No significant difference of trans-jasmonic acid (JA) was observed in citrus flower petals or pistils. However, a fivefold increase of cis-JA was detected. The amount of salicylic acid (SA) was elevated twofold in affected petals, but not in pistils. Northern blot analyses revealed that the genes encoding ACC oxidase or ACC synthase, and 12-oxo-phytodienoic acid (12-oxo-PDA) reductase, were highly expressed in affected flowers. The genes encoding auxin-related proteins also were upregulated. Application of 2-(4-chlorophenoxy)-2-methyl-propionic acid (clofibrate; a putative auxin inhibitor), 2,3,5-triiodobenzolic acid (an auxin transport inhibitor), or SA after inoculation significantly decreased the accumulation of the gene transcripts of auxin-responsive, GH3-like protein and 12-oxo-PDA reductase, but resulted in higher percentages of young fruit retention. The results indicate that imbalance of IAA, ethylene, and JA in C. acutatum-infected flowers may be involved in symptom development and young fruit drop.

38

Mou, Lan, Lang Zhang, Yujie Qiu, Mingchen Liu, Lijuan Wu, Xu Mo, Ji Chen, et al. "Endogenous Hormone Levels and Transcriptomic Analysis Reveal the Mechanisms of Bulbil Initiation in Pinellia ternata." International Journal of Molecular Sciences 25, no. 11 (June 3, 2024): 6149. http://dx.doi.org/10.3390/ijms25116149.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Pinellia ternata is a medicinal plant that has important pharmacological value, and the bulbils serve as the primary reproductive organ; however, the mechanisms underlying bulbil initiation remain unclear. Here, we characterized bulbil development via histological, transcriptomic, and targeted metabolomic analyses to unearth the intricate relationship between hormones, genes, and bulbil development. The results show that the bulbils initiate growth from the leaf axillary meristem (AM). In this stage, jasmonic acid (JA), abscisic acid (ABA), isopentenyl adenosine (IPA), and salicylic acid (SA) were highly enriched, while indole-3-acetic acid (IAA), zeatin, methyl jasmonate (MeJA), and 5-dexoxystrigol (5-DS) were notably decreased. Through OPLS-DA analysis, SA has emerged as the most crucial factor in initiating and positively regulating bulbil formation. Furthermore, a strong association between IPA and SA was observed during bulbil initiation. The transcriptional changes in IPT (Isopentenyltransferase), CRE1 (Cytokinin Response 1), A-ARR (Type-A Arabidopsis Response Regulator), B-ARR (Type-B Arabidopsis Response Regulator), AUX1 (Auxin Resistant 1), ARF (Auxin Response Factor), AUX/IAA (Auxin/Indole-3-acetic acid), GH3 (Gretchen Hagen 3), SAUR (Small Auxin Up RNA), GA2ox (Gibberellin 2-oxidase), GA20ox (Gibberellin 20-oxidase), AOS (Allene oxide synthase), AOC (Allene oxide cyclase), OPR (Oxophytodienoate Reductase), JMT (JA carboxy l Methyltransferase), COI1 (Coronatine Insensitive 1), JAZ (Jasmonate ZIM-domain), MYC2 (Myelocytomatosis 2), D27 (DWARF27), SMAX (Suppressor of MAX2), PAL (Phenylalanine Ammonia-Lyase), ICS (Isochorismate Synthase), NPR1 (Non-expressor of Pathogenesis-related Genes1), TGA (TGACG Sequence-specific Binding), PR-1 (Pathogenesis-related), MCSU (Molybdenium Cofactor Sulfurase), PP2C (Protein Phosphatase 2C), and SnRK (Sucrose Non-fermenting-related Protein Kinase 2) were highly correlated with hormone concentrations, indicating that bulbil initiation is coordinately controlled by multiple phytohormones. Notably, eight TFs (transcription factors) that regulate AM initiation have been identified as pivotal regulators of bulbil formation. Among these, WUS (WUSCHEL), CLV (CLAVATA), ATH1 (Arabidopsis Thaliana Homeobox Gene 1), and RAX (Regulator of Axillary meristems) have been observed to exhibit elevated expression levels. Conversely, LEAFY demonstrated contrasting expression patterns. The intricate expression profiles of these TFs are closely associated with the upregulated expression of KNOX(KNOTTED-like homeobox), suggesting a intricate regulatory network underlying the complex process of bulbil initiation. This study offers a profound understanding of the bulbil initiation process and could potentially aid in refining molecular breeding techniques specific to P. ternata.

39

Glickmann, Eric, Louis Gardan, Sylvie Jacquet, Shafik Hussain, Miena Elasri, Annik Petit, and Yves Dessaux. "Auxin Production Is a Common Feature of Most Pathovars of Pseudomonas syringae." Molecular Plant-Microbe Interactions® 11, no. 2 (February 1998): 156–62. http://dx.doi.org/10.1094/mpmi.1998.11.2.156.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

We investigated indole-3-acetic acid (IAA) production by 57 pathovars of Pseudomonas syringae and related species. Most of those analyzed produced IAA, especially in the presence of tryptophan. Eight strains produced high IAA concentrations in the absence of Trp. The iaaM and iaaH genes of P. savastanoi pv. savastanoi were detected in a limited number of strains only, including the eight above-mentioned strains. Thus, IAA synthesis in most assayed strains of P. syringae and related species does not involve genes highly similar to iaaM and iaaH. In contrast, the iaaL gene encoding an IAA-lysine synthase was detected in most pathovars, and was often found on plasmids.

40

Santos, Alexandre Bueno, Patrícia Silva Costa, Anderson Oliveira do Carmo, Gabriel da Rocha Fernandes, Larissa Lopes Silva Scholte, Jeronimo Ruiz, Evanguedes Kalapothakis, Edmar Chartone-Souza, and Andréa Maria Amaral Nascimento. "Insights into the Genome Sequence ofChromobacterium amazonenseIsolated from a Tropical Freshwater Lake." International Journal of Genomics 2018 (2018): 1–10. http://dx.doi.org/10.1155/2018/1062716.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Members of the genusChromobacteriumhave been isolated from geographically diverse ecosystems and exhibit considerable metabolic flexibility, as well as biotechnological and pathogenic properties in some species. This study reports the draft assembly and detailed sequence analysis ofChromobacterium amazonensestrain 56AF. The de novo-assembled genome is 4,556,707 bp in size and contains 4294 protein-coding and 95 RNA genes, including 88 tRNA, six rRNA, and one tmRNA operon. A repertoire of genes implicated in virulence, for example, hemolysin, hemolytic enterotoxins, colicin V, lytic proteins, and Nudix hydrolases, is present. The genome also contains a collection of genes of biotechnological interest, including esterases, lipase, auxins, chitinases, phytoene synthase and phytoene desaturase, polyhydroxyalkanoates, violacein, plastocyanin/azurin, and detoxifying compounds. Importantly, unlike otherChromobacteriumspecies, the 56AF genome contains genes for pore-forming toxin alpha-hemolysin, a type IV secretion system, among others. The analysis of theC. amazonensestrain 56AF genome reveals the versatility, adaptability, and biotechnological potential of this bacterium. This study provides molecular information that may pave the way for further comparative genomics and functional studies involvingChromobacterium-related isolates and improves our understanding of the global genomic diversity ofChromobacteriumspecies.

41

Da Costa, Maria Vera Jesus, Venkategowda Ramegowda, Sheshshayee Sreeman, and Karaba N. Nataraja. "Targeted Phytohormone Profiling Identifies Potential Regulators of Spikelet Sterility in Rice under Combined Drought and Heat Stress." International Journal of Molecular Sciences 22, no. 21 (October 28, 2021): 11690. http://dx.doi.org/10.3390/ijms222111690.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Rice cultivated under rainfed or semi-irrigated ecosystems is frequently exposed to a combination of drought and heat stress. As a sensitive crop at the reproductive stage, exposure to combined drought and heat stress will have a deleterious effect on yield. In this study, two rice cultivars with contrasting spikelet sterility, AVT2-5315 (low sterility) and AC35027 (high sterility), under combined stress were selected for physiological characterization and phytohormonal profiling at anthesis. Under combined stress, both cultivars did not differ in the physiological parameters such as relative water content, photosynthetic rate, light-adapted chlorophyll fluorescence and biomass, suggesting a similar source activity under stress. However, AVT2-5315 showed better yield due to better pollen and spikelet fertility than AC35027, suggesting its intrinsic tolerance ability under combined stress. Targeted profiling of 15 phytohormones from drought, heat and combined stress-treated flag leaf and spikelet tissues using LC–MS/MS showed increased accumulation of auxins (indole 3-acetic acid and indole 3-butyric acid) in flag leaves and jasmonic acid in spikelets of AVT2-5315, while there was increased accumulation of ethylene in flag leaves and methyl-jasmonate in spikelets of AC35027. Increased accumulation of these hormones correlated with key biosynthetic pathway genes. In the flag leaves, increased accumulation of auxins was correlated with increased transcript levels of YUCCA-like gene 1 (OsYUCCA1) and fish bone (OsFIB), in AVT2-5315 under combined stress. In AC35027, increased ethylene content was correlated with expression of 1-aminocyclopropane-1-carboxylate synthase 1 (OsASC1) and aminocyclopropane-1-carboxylic acid oxidase 2 (OsACO2). Similarly, in spikelets, increased accumulation of jasmonic acid in AVT2-5315 was correlated with expression of allene oxide cyclase (OsAOC) and 12-oxophytodienoic acid reductase 1 (OsOPR1). The mechanism of regulating spikelet sterility by these hormones needs further investigation towards improving rice tolerance to combined stress.

42

Beckie, Hugh J., Suzanne I. Warwick, Connie A. Sauder, Gina M. Kelln, and Chris Lozinski. "Acetolactate Synthase Inhibitor–Resistant False Cleavers (Galium spurium) in Western Canada." Weed Technology 26, no. 1 (March 2012): 151–55. http://dx.doi.org/10.1614/wt-d-11-00075.1.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Cleavers species (false cleavers and catchweed bedstraw) are among the top 10 most abundant weeds across the prairie region of western Canada, and are increasing in relative abundance at the fastest rate since the 1970s. In 2008, two false cleavers populations from Tisdale and Choiceland, Saskatchewan, were suspected of acetolactate synthase (ALS) –inhibitor resistance. Dose-response experiments were conducted with the use of imazethapyr and florasulam, both ALS inhibitors, as well as fluroxypyr, a synthetic auxin. Additionally, a 1,954–base-pair region of theALSgene including sites known to conferALSresistance were sequenced. Both populations were highly resistant to imazethapyr (resistance factors greater than 100), one population (Tisdale) was highly resistant to florasulam (Choiceland population susceptible, although a second, larger screening of 200 individuals indicated low frequency [2%] florasulam resistance), and both populations were susceptible to fluroxypyr. All sequenced Tisdale individuals screened with imazethapyr posessed the Trp574Leu mutation. In contrast, three point mutations were found for Choiceland individuals sequenced: Ser653Asn, Trp574Leu, and Asp376Glu. TheseALStarget-site mutations have not been documented previously in this species.

43

Kim, Woo Taek, Alan Campbell, Takaya Moriguchi, Ho Chul Yi, and Shang Fa Yang. "Auxin induces three genes encoding 1-aminocyclopropane-1-carboxylate synthase in mung bean hypocotyls." Journal of Plant Physiology 150, no. 1-2 (January 1997): 77–84. http://dx.doi.org/10.1016/s0176-1617(97)80184-8.

Full text

APA, Harvard, Vancouver, ISO, and other styles

44

Chen, Hao, and Liming Xiong. "myo-Inositol-1-phosphate Synthase Is Required for Polar Auxin Transport and Organ Development." Journal of Biological Chemistry 285, no. 31 (June 1, 2010): 24238–47. http://dx.doi.org/10.1074/jbc.m110.123661.

Full text

APA, Harvard, Vancouver, ISO, and other styles

45

Evans, Cody M., Seth A. Strom, Dean E. Riechers, Adam S. Davis, Patrick J. Tranel, and Aaron G. Hager. "Characterization of a waterhemp (Amaranthus tuberculatus) population from Illinois resistant to herbicides from five site-of-action groups." Weed Technology 33, no. 03 (May 23, 2019): 400–410. http://dx.doi.org/10.1017/wet.2019.19.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

AbstractExperiments were initiated to characterize a waterhemp population (CHR) discovered in a central Illinois corn field after it was not controlled by the 4-hydroxyphenylpyruvate dioxygenase (HPPD) inhibitor topramezone. Field experiments conducted during 2014–2015 indicated that acetolactate synthase (ALS)-, protoporphyrinogen oxidase (PPO)-, photosystem II (PSII)-, and HPPD-inhibiting herbicides and the synthetic auxin 2,4-D did not control the CHR population. Laboratory experiments confirmed target site–based resistance mechanisms to ALS- and PPO-inhibiting herbicides. Herbicide doses required to reduce dry biomass 50% (GR50) were determined in greenhouse dose–response experiments, and indicated 16-fold resistance to the HPPD inhibitor mesotrione, 9.5-fold resistance to the synthetic auxin 2,4-D, and 252-fold resistance to the PSII inhibitor atrazine. Complementary results from field, laboratory, and greenhouse investigations indicate that the CHR population has evolved resistance to herbicides from five sites of action (SOAs): ALS-, PPO-, PSII-, and HPPD-inhibiting herbicides and 2,4-D. Herbicide use history for the field in which CHR was discovered indicates no previous use of 2,4-D.

46

Xu, Jiaqi, Xudong Liu, Richard Napier, Liyao Dong, and Jun Li. "Mode of Action of a Novel Synthetic Auxin Herbicide Halauxifen-Methyl." Agronomy 12, no. 7 (July 12, 2022): 1659. http://dx.doi.org/10.3390/agronomy12071659.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Halauxifen-methyl is a new auxin herbicide developed by Corteva Agriscience (Wilmington, DE, USA). It has been suggested that ABF5 may be the target of halauxifen-methyl, as AFB5 mutants of Arabidopsis thaliana are resistant to halauxifen-methyl, which preferentially binds to AFB5. However, the mode of action of halauxifen-methyl has not yet been reported. Therefore, the aim of the present study was to reveal the mode of action of halauxifen-methyl by exploring its influence on indole-3-acetic acid (IAA) homeostasis and the biosynthesis of ethylene and Abscisic Acid (ABA) in Galium aparine. The results showed that halauxifen-methyl could disrupt the homeostasis of IAA and stimulate the overproduction of ethylene and ABA by inducing the overexpression of the 1-aminocyclopropane-1-carboxylate synthase (ACS) and 9-cis-epoxycarotenoid dioxygenase (NCED) genes involved in ethylene and ABA biosynthesis, finally leading to senescence and plant death.

47

Warwick, Suzanne I., Hugh J. Beckie, A. Gordon Thomas, and Tracey McDonald. "The biology of Canadian weeds. 8. Sinapis arvensis. L. (updated)." Canadian Journal of Plant Science 80, no. 4 (October 1, 2000): 939–61. http://dx.doi.org/10.4141/p99-139.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

An updated review of biological information is provided for Sinapis arvensis L. Native to the Old World, the species is widely introduced and naturalized in temperate regions around the world. The species occurs in all the provinces, the Northwest Territories, and the Yukon. It is an important weed of field crops in the Canadian prairies. A strongly persistent seedbank, competitive annual growth habit and high fecundity all contribute to its weedy nature and ensure that it will be a continuing problem. Several cases of herbicide resistance have been documented for natural populations of S. arvensis in Canada, including biotypes resistant to: i) Group 2 herbicides, which inhibit acetolactate synthase (ALS), from Manitoba in 1992 and Alberta in 1993; ii) Group 4 herbicides or synthetic auxins from Manitoba in 1991; and iii) Group 5 herbicides, which inhibit photosynthesis at photosystem II, from Ontario in 1983. The species is a close relative of Brassica nigra (L.) Koch, black mustard, and is capable of limited genetic exchange with the Brassica crop species under laboratory hybridization conditions either by conventional crossing or with the aid of ovary/embryo recovery techniques. Key words: Wild mustard, Sinapis arvensis, weed biology, herbicide resistance, risk assessment

48

Lloyd, Kirsten L., Jon M. Johnson, Arthur E. Gover, and James C. Sellmer. "Preemergence and Postemergence Suppression of Kochia on Rights-of-Way." Weed Technology 25, no. 2 (June 2011): 292–97. http://dx.doi.org/10.1614/wt-d-10-00117.1.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Kochia poses a challenge to vegetation management in both agricultural and noncrop areas. This species has developed widespread resistance to several herbicides with differing modes of action, including acetolactate synthase inhibitors and photosynthesis inhibitors. Resistance is also beginning to appear against the synthetic auxins and glycines. Therefore, alternative PRE and POST herbicides are needed for effective kochia management, especially in roadside bare-ground zones. Both PRE and POST herbicides were screened on rights-of-way in Pennsylvania. Mixtures containing diuron, flumioxazin, sulfentrazone, pendimethalin, prodiamine, and bromacil were evaluated for PRE activity in combination with glyphosate. POST kochia control was assessed for 15 noncrop herbicides. Results from all trials varied with kochia size and vigor at time of treatment. Although diuron is the current industry standard for PRE control in tank mixes, sulfentrazone appeared to have the most POST activity against vigorously growing kochia. All PRE herbicides evaluated performed better than the standard, sulfometuron plus chlorsulfuron alone. Dicamba, dicamba plus diflufenzopyr, fluroxypyr, and glyphosate performed best against kochia when applied POST. The recently available chemistries saflufenacil and aminocyclopyrachlor require further evaluation of application timing and use rates, respectively, for POST activity on kochia.

49

Velini, Edivaldo D., Maria L. B. Trindade, Luis Rodrigo M. Barberis, and Stephen O. Duke. "Growth Regulation and Other Secondary Effects of Herbicides." Weed Science 58, no. 3 (September 2010): 351–54. http://dx.doi.org/10.1614/ws-d-09-00028.1.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

As all herbicides act on pathways or processes crucial to plants, in an inhibitory or stimulatory way, low doses of any herbicide might be used to beneficially modulate plant growth, development, or composition. Glyphosate, the most used herbicide in the world, is widely applied at low rates to ripen sugarcane. Low rates of glyphosate also can stimulate plant growth (this effect is called hormesis). When applied at recommended rates for weed control, glyphosate can inhibit rust diseases in glyphosate-resistant wheat and soybean. Fluridone blocks carotenoid biosynthesis by inhibition of phytoene desaturase and is effective in reducing the production of abscisic acid in drought-stressed plants. Among the acetolactate synthase inhibitors, sulfometuron-methyl is widely used to ripen sugarcane and imidazolinones can be used to suppress turf species growth. The application of protoporphyrinogen oxidase inhibitors can trigger plant defenses against pathogens. Glufosinate, a glutamine synthetase inhibitor, is also known to improve the control of plant diseases. Auxin agonists (i.e., dicamba and 2,4-D) are effective, low-cost plant growth regulators. Currently, auxin agonists are still used in tissue cultures to induce somatic embryogenesis and to control fruit ripening, to reduce drop of fruits, to enlarge fruit size, or to extend the harvest period in citrus orchards. At low doses, triazine herbicides stimulate growth through beneficial effects on nitrogen metabolism and through auxin-like effects. Thus, sublethal doses of several herbicides have applications other than weed control.

50

Small, Zachary D., James D. McCurdy, Erick D. Begitschke, and Michael P. Richard. "Herbicides for Control of Wild Garlic in Turfgrass." HortTechnology 29, no. 6 (December 2019): 838–41. http://dx.doi.org/10.21273/horttech04379-19.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Abstract:

Wild garlic (Allium vineale) is an annual winter weed in managed turfgrass. Its dark green, upright stems are easily distinguishable among low-lying, dormant warm-season grasses. Experiments were conducted to determine the effectiveness of synthetic auxin and acetolactate synthase (ALS) inhibiting herbicides for post-emergence control of wild garlic. Trials were conducted in 2016 and 2017. Throughout both trial years, synthetic auxin herbicides exhibited visual control quicker than ALS inhibitors at the initial assessment date 20 d after application (DAA). Conversely, at the final assessment date 49 DAA, ALS inhibitors were the only treatments that controlled wild garlic by more than 85%. In 2016, plots treated with 2,4-D + dicamba + mecoprop at 4 pt/acre exhibited 88% visual control when assessed 20 DAA, but this level had decreased to 51% by 49 DAA. Similarly, visual control in plots treated with 2,4-D + mecoprop + dicamba + carfentrazone-ethyl at 4 pt/acre decreased from 59% to 56% and 82% to 18% between assessment dates in 2016 and 2017, respectively. Metsulfuron-methyl at 0.5 fl oz/acre controlled wild garlic 94% and 91% at the 49 DAA assessment date, whereas sulfentrazone + metsulfuron-methyl at 0.41 lb/acre controlled wild garlic 93% and 95% at the same assessment dates in 2016 and 2017, respectively. Future research should consider tank mixes of auxin-mimicking and ALS-inhibiting herbicides as potential routes for quick burndown and season-long control.

Journal articles on the topic 'Auxines de synthèse'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles