高温是制约苗木生长和发育的主要环境因子,也给林业安全生产带来极大隐患。近年越来越多的研究证实高温对Rubisco和光合作用的抑制主要是通过抑制Rubisco活化酶（RCA）起作用的，但RCA在高温中的作用还远未阐明。本课题组前期研究发现，在高温胁迫下山核桃苗木RCA活性降低，但并不降解，同时，大量合成一氧化氮（NO），我们推测NO可能诱导了RCA蛋白发生亚硝基化修饰，而该修饰对RCA蛋白转运、RCA与类囊体膜互作、光合功能调控方面可能具有重要作用。因此本研究从RCA亚硝基化修饰入手研究高温对山核桃苗木RCA的影响，并对RCA亚硝基化修饰作用与RCA定位变化、类囊体膜的热稳定性、光合作用的高温抗性的相互关系进行详尽描述。这些研究理论上可以进一步揭示木本植物的高温适应新机制，实践上可以为林业生产上培育抗高温苗木和提高苗木抗高温的技术措施提供指导，也为其它植物的耐高温研究寻找理论依据。

The high temperature is the main environmental factors constraining the growth and development of seedlings, and also brings great risks to the production safety of forestry. In recent years, a growing number of studies confirm that the inhibition of Rubisco and photosynthesis under high temperature stress is induced by inhibiting Rubisco activase (RCA) activity. However, the role of RCA at high temperatures stress remains unclear. Our group preliminary study found that the RCA activity was decreased while the RCA did not degrade in Carya cathayensis seedlings under high temperature stress, and that the release of nitric oxide (NO) was increased significantly under high temperature stress. We speculated that this NO induced S-nitrosylation modification of RCA protein under such condition. That may play an important role on RCA protein transport, RCA and thylakoid membrane interaction, and regulation of photosynthetic function. Therefore, in the present study, we will investigate the effects of high temperature on the S-nitrosylation modification of RCA protein, and study the relationship between the S-nitrosylated RCA protein and cellular localization of RCA, thylakoid membrane thermal stability, and high temperature resistance of photosynthesis in Carya cathayensis seedlings. These studies are expected to further reveal the high temperature adaptation mechanisms of wood plants, and hopeful in providing guidance to cultivate high temperature -resistant genotypes of wood plants and improve the technology of high temperature resistance in forestry production practice, furthermore, to find a theoretical basis in researches of other plants.