番茄JRG1基因负调控茉莉素介导的抗性反应的分子机制研究

Tomato (Solanum lycopersicum) occupies an important position in our vegetable production. However, root knot nematodes（RKN）disease generally occurs because of successive cultivation. Jasmonate (JA) is a defensive plant hormone that regulates various abiotic and biotic stress，but little is known about the signal transduction mechanism for jasmonate-regulated defense response against RKN in tomato...In our previous work, we preliminarily obtained a transcription factor JRG1 which interacted with JAZ and negatively regulated the resistance of RKN in tomato. In this project, we will further study the function, expression pattern and subcellular localization of JRG1, verify the interaction between JRG1 and JAZ, explore the downstream pathway of JRG1-regulated plant defense, and ultimately reveal the molecular basis of JRG1 as a negative regulator mediated the response of tomato against RKN...This project will enrich our understanding of plant defense mechanism against biotic stress, and provide reference for establishing green and sustainable vegetable production.

番茄是我国设施栽培面积较大的茄果类蔬菜之一，但连年栽培导致番茄根结线虫病越来越严重。茉莉素作为防御型植物激素调控番茄根结线虫的抗性，但其中的分子机制尚不完全清楚。前期工作中，我们获得了一个响应茉莉素和根结线虫的转录因子JRG1（Jasmonate and Root-knot nematode infection-induced Gene 1），初步研究结果表明JRG1与茉莉素途径抑制因子JAZ互作，且负调控番茄根结线虫的抗性反应。本项目中，我们将深入研究JRG1的抗性功能、表达模式、亚细胞定位、与JAZ互作的真实性，探索JRG1调控番茄根结线虫抗性反应的下游通路，最终揭示JRG1作为负调节因子参与茉莉素途径抑制番茄根结线虫抗性的分子机制。本项目的实施和完成将丰富人们对番茄防御生物胁迫机制的认识，为培育抗根结线虫的番茄栽培品种、建立绿色和可持续发展的番茄生产提供参考。

根结线虫是世界第二大土传病害。植物激素茉莉素（JAs）调控番茄对根结线虫的抗性，然而，其作用机制尚不清楚。该研究发现SlJRG1/SlWRKY45与大多数的茉莉素信号转导途径的抑制子SlJAZs互作。SlJRG1/SlWRKY45过表达减弱了番茄对南方根结线虫的抗性，而sljrg1/slwrky45突变体增强了其抗性。SlJRG1/SlWRKY45直接结合茉莉素合成基因SlAOC，并抑制其表达，进而调控南方根结线虫操控的茉莉素的合成。综上所述，本项目揭示了SlJRG1/SlWRKY45参与茉莉素合成和信号转导途径调控番茄对南方根结线虫抗性的分子机制。该研究为揭示茉莉素调控番茄抗根结线虫的分子机制提供了新的理论依据。