过氧化氢介导的质体反向信号的作用机理及其生理功能研究

Plastid retrograde signaling plays a crucial role in coordinating the expression of photosynthesis-associated nuclear genes (PhANGs), and is essential for chloroplast biogenesis and functional maintenance in response to changing environmental stimuli. Among those characterized plastid signaling pathways, Hydrogen Peroxide (H2O2)-dependent Retrograde Signaling (HPRS) plays an important role in maintaining the function of the chloroplast under adverse extreme abiotic and biotic stresses, such as high light (HL), drought, high temperature (HT) and cold, as well as pathogen invasion. However, we only know very little about the underlying mechanism of HPRS in higher plants. Therefore, this project aims to generate the mapping populations and identify the mutant genes for previously isolated hprs1 mutants, to systematically characterize their physiological phenotypes and to dissect the molecular mechanism of HPRS by combining biomolecular, biochemical, and genetic strategies.

质体反向信号在协调光合作用相关的基因（PhANGs）表达中扮演了重要的角色，对于环境胁迫条件下叶绿体的发育和功能维护也是至关重要的。当植物遭受到诸如强光，干旱，高温，冻害，以及病菌侵害等极端的生物和非生物胁迫时，过氧化氢依赖的质体反向信号途径（Hydrogen Peroxide (H2O2)-dependent Retrograde Signaling (HPRS)）对于维护叶绿体的功能是非常重要的。然而，我们对高等植物的HPRS的作用机理却知之甚少。因此，该项目将以前期筛选到的hprs1突变体为研究素材，构建图位克隆群体，鉴定突变基因，系统的研究突变体的生理表型，并综合运用分子生物学、生物化学和遗传学等研究策略来解析HPRS的分子机理。

通过项目的实施，我们运用图位克隆和二代基因组测序技术成功的克隆到了hprs1突变体的突变位点。通过基因互补和筛选T-DNA插入突变体等遗传手段进一步验证了突变位点。通过RNA-seq分析检测了hprs1参与调控的靶基因，并针对这些靶基因，我们分析了HPRS1依赖的信号调控叶绿体基因表达和气孔发育的分子机理。通过酵母双杂交我们筛选到了与HPRS1特异互做的靶蛋白RPT2，并进一步通过生化和生理检测，分析了HPRS1介导的过氧化氢信号依赖于RPT2来调控根系发育和响应氮胁迫的分子机制。这些重要的研究结果为我们深入系统的理解HPRS1介导的过氧化氢信号在调控气孔发育和根系发育中的分子机制提供了关键的实验证据。