Mutant analysis in Arabidopsis provides insight into the molecular mode of action of the auxinic herbicide dicamba

Herbicides that mimic the natural auxin indole-3-acetic acid are widely used in weed control. One common auxin-like herbicide is dicamba, but despite its wide use, plant gene responses to dicamba have never been extensively studied. To further understand dicamba's mode of action, we utilized Ar...

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Main Authors: Gleason, C., Foley, R., Singh, Karambir
Format: Journal Article
Published: Public Library of Science 2011
Online Access:http://hdl.handle.net/20.500.11937/16907
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author Gleason, C.
Foley, R.
Singh, Karambir
author_facet Gleason, C.
Foley, R.
Singh, Karambir
author_sort Gleason, C.
building Curtin Institutional Repository
collection Online Access
description Herbicides that mimic the natural auxin indole-3-acetic acid are widely used in weed control. One common auxin-like herbicide is dicamba, but despite its wide use, plant gene responses to dicamba have never been extensively studied. To further understand dicamba's mode of action, we utilized Arabidopsis auxin-insensitive mutants and compared their sensitivity to dicamba and the widely-studied auxinic herbicide 2,4-dichlorophenoxyacetic acid (2,4-D). The mutant axr4-2, which has disrupted auxin transport into cells, was resistant to 2,4-D but susceptible to dicamba. By comparing dicamba resistance in auxin signalling F-box receptor mutants (tir1-1, afb1, afb2, afb3, and afb5), only tir1-1 and afb5 were resistant to dicamba, and this resistance was additive in the double tir1-1/afb5 mutant. Interestingly, tir1-1 but not afb5 was resistant to 2,4-D. Whole genome analysis of dicamba-induced gene expression showed that 10 hours after application, dicamba stimulated many stress-responsive and signalling genes, including those involved in biosynthesis or signalling of auxin, ethylene, and abscisic acid (ABA), with TIR1 and AFB5 required for the dicamba-responsiveness of some genes. Research into dicamba-regulated gene expression and the selectivity of auxin receptors has provided molecular insight into dicamba-regulated signalling and could help in the development of novel herbicide resistance in crop plants.
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spelling curtin-20.500.11937-169072017-09-13T15:43:56Z Mutant analysis in Arabidopsis provides insight into the molecular mode of action of the auxinic herbicide dicamba Gleason, C. Foley, R. Singh, Karambir Herbicides that mimic the natural auxin indole-3-acetic acid are widely used in weed control. One common auxin-like herbicide is dicamba, but despite its wide use, plant gene responses to dicamba have never been extensively studied. To further understand dicamba's mode of action, we utilized Arabidopsis auxin-insensitive mutants and compared their sensitivity to dicamba and the widely-studied auxinic herbicide 2,4-dichlorophenoxyacetic acid (2,4-D). The mutant axr4-2, which has disrupted auxin transport into cells, was resistant to 2,4-D but susceptible to dicamba. By comparing dicamba resistance in auxin signalling F-box receptor mutants (tir1-1, afb1, afb2, afb3, and afb5), only tir1-1 and afb5 were resistant to dicamba, and this resistance was additive in the double tir1-1/afb5 mutant. Interestingly, tir1-1 but not afb5 was resistant to 2,4-D. Whole genome analysis of dicamba-induced gene expression showed that 10 hours after application, dicamba stimulated many stress-responsive and signalling genes, including those involved in biosynthesis or signalling of auxin, ethylene, and abscisic acid (ABA), with TIR1 and AFB5 required for the dicamba-responsiveness of some genes. Research into dicamba-regulated gene expression and the selectivity of auxin receptors has provided molecular insight into dicamba-regulated signalling and could help in the development of novel herbicide resistance in crop plants. 2011 Journal Article http://hdl.handle.net/20.500.11937/16907 10.1371/journal.pone.0017245 Public Library of Science unknown
spellingShingle Gleason, C.
Foley, R.
Singh, Karambir
Mutant analysis in Arabidopsis provides insight into the molecular mode of action of the auxinic herbicide dicamba
title Mutant analysis in Arabidopsis provides insight into the molecular mode of action of the auxinic herbicide dicamba
title_full Mutant analysis in Arabidopsis provides insight into the molecular mode of action of the auxinic herbicide dicamba
title_fullStr Mutant analysis in Arabidopsis provides insight into the molecular mode of action of the auxinic herbicide dicamba
title_full_unstemmed Mutant analysis in Arabidopsis provides insight into the molecular mode of action of the auxinic herbicide dicamba
title_short Mutant analysis in Arabidopsis provides insight into the molecular mode of action of the auxinic herbicide dicamba
title_sort mutant analysis in arabidopsis provides insight into the molecular mode of action of the auxinic herbicide dicamba
url http://hdl.handle.net/20.500.11937/16907