参与激发水杨酸通路诱导番茄抗根结线虫的生防菌Jdm2关键基因功能鉴定

Root knot nematode (RKN) is a devastating plant soil-born pathogen. Using biocontrol bacteria to promote plant resistance is an environmental friendly and sustainable solution. But the mechanisms of the biocontrol is little understood. Previously, we have identified a Bacillus subtilis strain Jdm2 that showed high biocontrol efficacy of RKN on tomato. Furthermore, I have demonstrated that Jdm2 induced resistance to RKN required an activation of salicylic acid (SA) pathway in tomato. In this project, I will focus on biocontrol bacteria Jdm2, to identify the key genes of Jdm2 that contribute to the induction of SA in tomato. Following a Jdm2 mutant library construction, I will screen for mutant strains that show altered capability of inducing tomato resistance to RKN and activating of SA pathway. Using whole genome sequencing technique, the malfunction gene in the mutant will be isolated. By generating and transforming gene expression constructs in to the mutant or E. coli followed with an evaluation of the induced tomato resistance to RKN, the gene function of activation of SA pathway will be confirmed. This study will lead to a better understanding of biocontrol bacteria genes that play a role in inducing tomato resistance to RKN.

根结线虫寄主广范，危害严重，利用拮抗菌株控制该病害已经成为有效的手段，但是对线虫病害生防的机理研究很少。枯草芽孢杆菌Jdm2是我们分离获得具有自主知识产权的生防菌，对番茄根结线虫具有很好的防效，项目前期研究发现Jdm2能够通过激发番茄水杨酸（SA）通路诱导番茄对根结线虫的抗性。本次立项将以激发子来源为重点，鉴定在番茄SA通路激发过程发挥关键作用的Jdm2生防菌基因，拟利用芽孢杆菌转座诱变体系构建Jdm2突变体文库，筛选出对SA通路激发活性改变的突变菌株，借助全基因组测序技术挖掘突变体中失活的功能基因，通过原核表达获得功能基因产物和构建回补突变体菌株，对该基因参与诱发番茄SA通路的功能进行验证，研究结果有望明确参与SA途径诱导番茄抗根结线虫的生防菌Jdm2的关键基因，为线虫病害的防控提供新的思路和材料。

根结线虫寄主广范，危害严重，利用拮抗菌株控制该病害已经成为有效的手段。高地芽孢杆菌JSCX-1对番茄根结线虫具有很好的防效，本项目研究发现JSCX-1能够通过激发番茄水杨酸（SA）通路诱导番茄对根结线虫的抗性。通过化学诱变方法构建了JSCX-1突变体文库，初步筛选到对SA通路激发活性改变的突变菌株，借助全基因组测序技术挖掘突变体中失活的功能基因，对该基因参与诱发番茄SA通路的功能进行验证，研究结果表明水杨酸信号通路可能在JSCX-1诱导番茄抗根结线虫中发挥重要作用。同时我们定位到了一个可能的相关基因oppA。但该基因是否和诱导番茄产生线虫抗性有关，仍需进一步详细的研究。这些研究结果为线虫病害的防控提供新的思路和材料。