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Plant Physiology:烟草生物钟组分ZTL介导食草动物防御

时间:2018-05-08 11:56 作者:未知
 

 

 


ZEITLUPE in the roots of wild tobacco regulates jasmonate-mediated nicotine biosynthesis and resistance to a generalist herbivore
First author:Ran Li;Affiliations:Max Planck Institute for Chemical Ecology(普朗克化学生态学研究所):Jena, GermanyCorresponding author:Ian T Baldwin
The jasmonate (JA) phytohormone signaling system is an important mediator of plant defense against herbivores (食草动物). Plants deficient in JA signaling are more susceptible to herbivory as a result of deficiencies in defensive trait expression. Recent studies have implicated the circadian clock in regulating JA-mediated defenses, but the molecular mechanisms linking the clock to JA signaling are unclear. Here we report that wild tobacco (Nicotiana attenuata) plants rendered deficient in the clock component ZEITLUPE (ZTL) by RNA interference (RNAi) have attenuated (减弱的) resistance to the generalist herbivoreSpodoptera littoralis(海灰翅夜蛾). This effect can be attributed in part to reduced concentrations of nicotine (烟碱), an abundant JA-regulated toxin produced inN. attenuataroots and transported to shoots. RNAi targeting ZTL dramatically affects the root circadian clock and reduces the expression of nicotine biosynthetic genes. Protein-protein interaction experiments demonstrate that ZTL regulates JA signaling by directly interacting with JAZ proteins in a COI1- and JA-Ile-independent manner, thereby regulating a JAZ-MYC2 module that is required for nicotine biosynthesis. Our study reveals new functions for ZTL and proposes a mechanism by which a clock component directly influences JA signaling to regulate plant defense against herbivory.


茉莉酸JA信号通路是植物抵抗食草动物的重要调控子。JA信号通路缺陷会使得植物抗性位点表达有所缺陷,进而更易受到食草动物的侵袭。近来的一些研究显示昼夜节律在植物JA介导的抗性防御中起到重要作用,然而具体的分子机制还不清楚。本文报道了通过RNAi技术导致野生烟草生物钟组分ZTL缺陷会减弱其对于食草动物海灰翅夜蛾的抗性。该效应可能部分归因于烟草中烟碱浓度的降低,而烟碱是由JA所调控的一种毒性物质,在烟草根部合成,而后被转运到地上组织。RNAi干扰ZTL会影响根的生物钟,减少烟碱生物合成相关基因的表达。蛋白质互作试验显示ZTL直接通过COI1和JA-Ile依赖性的方式与JAZ蛋白互作调控JA信号转导,进而调控对于烟碱生物合成非常重要的JAZ-MYC2模块。本文的发现揭示了ZTL的新的生物学功能,同时提出了一个生物钟组分直接通过影响JA信号通路来调控植物抗食草动物的分子机制。

通讯:Ian T Baldwin(https://www.mpg.de/421027/chemische_oekologie_wissM)
个人简介:1981年,美国达特茅斯学院,生物学学士;1989年,康奈尔大学,化学生态学博士。

doi:https://doi.org/10.1104/pp.18.00315
Journal:Plant PhysiologyFirst Published date: 02 May,2018