The maize transcription factor EREB58 mediates the jasmonate-induced production of sesquiterpene volatiles
The maize transcription factor EREB58 mediates the jasmonate-induced production of sesquiterpene volatiles
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玉米转录因子 EREB58 介导茉莉酸诱导的倍半萜挥发物的产生
DOI：
10.1111/tpj.12994
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发表时间：
2015-10-01
期刊：
影响因子：
7.2
通讯作者：
Lang, Zhihong
中科院分区：
文献类型：
--
作者：
Li, Shengyan;Wang, Hai;Lang, Zhihong
在过去的二十年里，玉米（Zea mays）已被建立为研究植物对食草动物的间接防御的模式系统。当被鳞翅目幼虫攻击时，玉米叶片会释放出一种主要由倍半萜组成的复杂混合挥发物，以吸引食草动物的天敌。这与萜烯脱氢酶如TPS 10的快速转录诱导有关;然而，在此过程中控制复杂转录重编程的分子组分仍然不清楚。在此，通过利用玉米TPS 10启动子在拟南芥中保持其对植食性的完全响应性的发现，我们通过缺失作图鉴定了TPS 10启动子的-300至-200区域对于其植食性诱导是必需的和充分的。以该启动子区为诱饵，对拟南芥转录因子文库进行高通量筛选，鉴定出7个AP 2/ERF家族转录因子。EREB 58是玉米中唯一对植食性有反应的基因，其时空表达模式与TPS 10高度相似。同时，EREB 58对茉莉酸也有反应。体内和体外分析表明，EREB 58通过直接结合到TPS 10启动子的-300至-200区域内的GCC盒来促进TPS 10表达。过表达EREB 58的转基因玉米植物组成型地过量积累TPS 10转录物，以及（E）-β-法呢烯和（E）-β-香柠檬烯，这两种主要的倍半萜烯由TPS 10产生。相反，茉莉酸诱导的TPS 10和其挥发物被废除EREB 58-RNAi转基因株系。总之，这些结果表明，EREB 58是一个积极的调节剂的倍半萜生产，直接促进TPS 10的expression.Significance Statement在玉米中，一个防御反应，对草食动物是增加倍半萜挥发物，这反过来吸引天敌的草食动物。在这里，我们表明，茉莉酸和草食动物响应转录因子促进萜烯合成酶的表达和生产的倍半萜挥发物。
Over the past two decades, Zea mays (maize) has been established as a model system for the study of indirect plant defense against herbivores. When attacked by lepidopteran larvae, maize leaves emit a complex blend of volatiles, mainly composed of sesquiterpenes, to attract the natural enemies of the herbivores. This is associated with a swift transcriptional induction of terpene synthases such as TPS10; however, the molecular components controlling the complex transcriptional reprogramming in this process are still obscure. Here, by exploiting the finding that the maize TPS10 promoter retained its full responsiveness to herbivory in Arabidopsis, we identified the region from -300 to -200 of the TPS10 promoter as both necessary and sufficient for its herbivore inducibility through 5 deletion mapping. A high-throughput screening of an Arabidopsis transcription factor library using this promoter region as the bait identified seven AP2/ERF family transcription factors. Among their close homologs in maize, EREB58 was the only gene responsive to herbivory, with a spatiotemporal expression pattern highly similar to that of TPS10. Meanwhile, EREB58 was also responsive to Jasmonate. In vivo and in vitro assays indicated that EREB58 promotes TPS10 expression by directly binding to the GCC-box within the region from -300 to -200 of the TPS10 promoter. Transgenic maize plants overexpressing EREB58 constitutively over-accumulate TPS10 transcript, and also (E)--farnesene and (E)--bergamotene, two major sesquiterpenes produced by TPS10. In contrast, jasmonate induction of TPS10 and its volatiles was abolished in EREB58-RNAi transgenic lines. In sum, these results demonstrate that EREB58 is a positive regulator of sesquiterpene production by directly promoting TPS10 expression.Significance Statement In maize, one defense response against herbivores is to increase sesquiterpene volatiles which in turn attract natural enemies of herbivores. Here we demonstrate that a jasmonate- and herbivore-responsive transcription factor promotes terpene synthase expression and production of sesquiterpene volatiles.