棉株GbTRP1的下调导致邻氨基苯甲酸的积累从而增强了对黄萎病抗性
苗玉焕，朱龙付，张献龙
背景：
黄萎病（Verticillium wilt）是由大丽轮枝菌（Verticillium dahliae）引起的一种棉花病害，被称为棉花的“癌症”。防御相关基因的发现和鉴定对抗黄萎病品种的选育具有重要意义。在以前的研究中，我们确定了一些可能的广谱抗性基因。本文报道了色氨酸合成相关基因GbTRP1及其与棉花抗性的功能分析。
结果：
表达分析表明，棉花感染大丽轮枝菌后1 h和6 h时GbTRP1的表达受到抑制，12 h和24 h时被激活，而经水杨酸和茉莉酸处理后，GbTRP1的表达被高度诱导。亚细胞定位研究表明GbTRP1位于叶绿体中。抑制GbTRP1表达导致了棉花的病变模拟表型，并通过增强对大丽轮枝菌（V. dahliae）和灰霉病菌（B. cinerea）的抗性激活了棉花的免疫应答。代谢组学分析表明，在GbTRP1基因沉默的棉株中，邻氨基甲酸化合物大量积累，这些代谢产物在体外可以抑制V. dahliae和B. cinerea的生长。
结论：
研究结果表明，抑制GbTRP1的表达可以显著激活棉花的免疫应答，增强其对V. dahliae和B. cinerea的抗性，这可能是邻氨基甲酸化合物积累的结果。本研究不仅为棉花抗病育种提供了遗传资源，而且为棉花抗真菌病害的化学防治新方法提供了依据。
Background
Verticillium wilt, caused by Verticillium dahliae, is called a “cancer” disease of cotton. The discovery and identification of defense-related genes is essential for the breeding of Verticillium wilt-resistant varieties. In previous research we identified some possible broad-spectrum resistance genes. Here, we report a tryptophan synthesis-related gene GbTRP1 and its functional analysis in relation to the resistance of cotton to V. dahliae.
Results
Expression analysis shows that GbTRP1 is suppressed at 1?h and 6?h post V. dahliae infection, but activated at 12?h and 24?h, and the expression of GbTRP1 is highly induced by treatment with salicylic acid and jasmonic acid. Sub-cellular localization studies show that GbTRP1 is localized in the chloroplast. Suppression of GbTRP1 expression leads to lesion-mimic phenotypes and activates the immune response in cotton by showing enhanced resistance to V. dahliae and B. cinerea. Metabolomic analysis shows that anthranilic compounds significantly accumulated in GbTRP1-silenced plants, and these metabolites can inhibit the growth of V. dahliae and B. cinerea in vitro.
Conclusions
Our results show that suppression of GbTRP1 expression dramatically activates the immune response and increases resistance of cotton to V. dahliae and B. cinerea, possibly due to the accumulation of anthranilate compounds. This study not only provides genetic resources for disease resistance breeding, but also may provide a basis for new chemical control methods for combatting of fungal disease in cotton.
Title: Down regulation of cotton GbTRP1 leads to accumulation of anthranilates and confers resistance to Verticillium dahliae
Authors: MIAO Yuhuan, ZHU Longfu and ZHANG Xianlong
Journal of Cotton Research. 2019; 2:19
https://doi.org/10.1186/s42397-019-0034-1
发布日期: 2019-11-21
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