Solanum lycopersicum IAA15 functions in the 2,4-dichlorophenoxyacetic acid herbicide mechanism of action by mediating abscisic acid signalling.
Solanum lycopersicum IAA15 functions in the 2,4-dichlorophenoxyacetic acid herbicide mechanism of action by mediating abscisic acid signalling.
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DOI：
10.1093/jxb/erv199
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发表时间：
2015-07
影响因子：
6.9
通讯作者：
Tao Xu;Yanling Wang;Xin Liu;Song Gao;M. Qi;Tianlai Li
中科院分区：
文献类型：
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作者：
Tao Xu;Yanling Wang;Xin Liu;Song Gao;M. Qi;Tianlai Li
2，4-二氯苯氧基乙酸(2，4-D)是一种重要的植物生长调节剂，是世界上最常用的除草剂。然而，阔叶水果和蔬菜对除草剂极其敏感，如果使用方式与指示不一致，可能会造成损害并导致作物损失。尽管对2，4-D的机制有了详细的了解，但对生长素信号的调控仍然不清楚。例如，虽然生长素信号的主要中介，包括生长素/吲哚乙酸(AUX/IAA)蛋白和生长素反应因子(ARF)，都是已知的介导生长素除草剂的，但其潜在的机制仍不清楚。本研究探讨了2，4-D对番茄AUX/IAA基因表达的影响，并选择了最显著上调的两个基因SlIAA15和SlIAA29进行进一步研究。Western blotting结果表明，S1IAA15和S1IAA29基因大量积累，脱落酸(ABA)和乙烯处理提高了相应基因的表达水平。过量表达SlIAA15，而不是SlIAA29，诱导了2，4-D除草剂的损伤表型。35S：：SlIAA15叶片气孔密度显著降低，一些可能参与气孔分化调控的R2R3MYB基因表达发生改变。进一步的研究表明，35S：：SlIAA15的根伸长对ABA处理很敏感，很可能是由于ABA信号转导基因的表达发生了变化。此外，还探讨了SLIAA15转化子对生长素敏感性的改变。这些结果表明，SLIAA15在决定除草剂2，4-D的药效中起着重要作用。
2,4-Dichlorophenoxyacetic acid (2,4-D), an important plant growth regulator, is the herbicide most commonly used worldwide to control weeds. However, broad-leaf fruits and vegetables are extremely sensitive to herbicides, which can cause damage and result in lost crops when applied in a manner inconsistent with the directions. Despite detailed knowledge of the mechanism of 2,4-D, the regulation of auxin signalling is still unclear. For example, although the major mediators of auxin signalling, including auxin/indole acetic acid (AUX/IAA) proteins and auxin response factors (ARFs), are known to mediate auxinic herbicides, the underlying mechanisms are still unclear. In this study, the effects of 2,4-D on AUX/IAA gene expression in tomato were investigated, and the two most notably up-regulated genes, SlIAA15 and SlIAA29, were selected for further study. Western blotting revealed the substantial accumulation of both SlIAA15 and SlIAA29, and the expression levels of the corresponding genes were increased following abscisic acid (ABA) and ethylene treatment. Overexpressing SlIAA15, but not SlIAA29, induced a 2,4-D herbicide damage phenotype. The 35S::SlIAA15 line exhibited a strong reduction in leaf stomatal density and altered expression of some R2R3 MYB genes that are putatively involved in the regulation of stomatal differentiation. Further study revealed that root elongation in 35S::SlIAA15 was sensitive to ABA treatment, and was most probably due to the altered expression of an ABA signal transduction gene. In addition, the altered auxin sensitivities of SlIAA15 transformants were also explored. These results suggested that SlIAA15 plays an important role in determining the effects of the herbicide 2,4-D.