拟南芥FtsH蛋白TU31协调环境温度与叶绿体发育的分子机理

叶绿体对于高等植物来说是必不可少的，它不仅是植物进行光合作用的场所，而且能够合成代谢产物以及感知外界环境的刺激。植物特别是农作物的生长和发育对环境温度变化十分敏感，叶绿体发育受到温度和光照等多种非生物因素的调控,但植物如何协调叶绿体发育与环境温度变化的分子机制还有待深入研究。本项目通过正向遗传筛选得到一个温度条件型叶绿体发育缺陷拟南芥突变体tu31。该突变体在22℃出现微弱黄化表型，当生长温度降低至16℃时黄化表型更加明显，而当温度升高到29℃时其叶绿体发育与野生型相似。通过图位克隆和基因组重测序分析发现TU31基因编码一个功能未知的FtsH蛋白。本项目将研究TU31调控叶绿体发育的分子机理、响应温度变化分子机理以及影响叶绿体蛋白亚细胞定位或稳定性的机制。通过对TU31功能的深入研究，可以阐明植物响应温度变化调控叶绿体发育的新机制，增强人们对植物适应环境温度变化分子机制的认识。

Chloroplasts are indispensable for higher plants. They are not only the exclusive sites of photosynthesis, but also can synthesize many metabolites and are sensitive to changes in environmental conditions. The growth and development of plants, especially crops, are very sensitive to environmental temperature changes, and chloroplast development is regulated by a variety of abiotic factors such as temperature and light. However, the molecular mechanism of how plants coordinate chloroplast development and environmental temperature changes remains to be further studied. In this project, a temperature-conditioned chloroplast development defect mutant tu31 of Arabidopsis was obtained through forward genetic screening. The tu31 mutant showed a weak yellowing phenotype at 22 °C. The yellowing phenotype was more pronounced when the growth temperature was reduced to 16 °C, and its chloroplast development was similar to that of the wild type when the temperature was increased to 29 °C. Map-based cloning and genomic resequencing analysis revealed that TU31 gene encodes an FtsH protein of unknown function. This project will investigate the molecular mechanism of how TU31 regulates chloroplast development and responds to temperature changes, and that TU31 affects the subcellular localization or stability of chloroplast proteins. Through in-depth study of the function of TU31, it is possible to clarify the new mechanism for plants to regulate chloroplast development in response to temperature changes and enhance the understanding of the molecular mechanism of plant adaptation to environmental temperature changes.