miR156调控气体信号分子H2S产生诱导番茄气孔关闭的分子机理

气孔开度大小影响园艺作物的许多重要农艺性状，是研究作物胁迫适应机制的模式指标。气体信号分子硫化氢（H2S）被证明诱导气孔关闭，但对于该过程中内源H2S产生的上游调控网络知之甚少。植物miRNA调控H2S产生机理的研究也十分薄弱。前期我们发现，抑制miR156功能的转基因番茄中内源H2S含量显著升高，幼叶气孔开度减小。荧光定量结果表明抑制miR156功能增强番茄H2S产生基因的表达。这些结果暗示miR156作为H2S信号的上游因子调控番茄幼叶气孔开度，我们推测miR156通过其靶标蛋白SPL调控番茄H2S产生基因的转录。基于此，本项目以番茄为材料，研究miR156-SPL-H2S模块对气孔运动的调控，采用生化、分子、遗传等研究方法系统探索番茄miR156/SPL调控H2S产生基因表达的分子机制，为从miRNA角度扩展H2S信号上游调控网络提供依据，为通过基因工程手段优化番茄栽培提供理论支撑。

Stomatal aperture can affect many important traits with agronomic significance, and is also an important model index to study the stress adaptation mechanism of horticultural crops. Hydrogen sulfide (H2S), a vital gasotransmitter, has been demonstrated to induce stomatal closure, but little is known about the upstream regulatory network of endogenous H2S generation. The molecular mechanism underlying miRNA regulated H2S production has not been reported. Previously, we found that in the transgenic tomatoes with inhibited miR156 function, the endogenous H2S content increased significantly and the stomatal aperture of juvenile leaves decreased. Moreover, our preliminary qPCR data showed that inhibiting miR156 function enhanced the expression of H2S generation-associated genes in tomato. All these results strongly hinted that miR156 acts as an upstream factor of H2S signal mediating stomatal movement in juvenile leaves of tomato. We thus speculated that miR156 regulates the expression of H2S generation-associated genes through its target SPL protein in tomato. Based on these results, we use tomato as material in this project to systematically explore the molecular mechanism underlying miR156/SPL-mediated transcriptional regulation of H2S generation-associated gene by using biochemical, molecular biological and genetic means, so as to clarify the regulation of miR156-SPL-H2S module on stomatal movement in tomato. The research of this project will provide not only a basis for expanding the upstream regulatory network of H2S signal from miRNA perspective, but also a theoretical support for creating optimized tomato through genetic manipulation.