BY: Gleason C, Foley RC, Singh KB.
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.Yangzhou pioneer chemical CO.,LTD.
没有评论:
发表评论