生物胁迫和非生物胁迫等环境不利因素通常诱导一氧化氮（nitric oxide, NO）等信号分子产生，导致激活防御反应或胁迫反应，同时介导生长发育抑制，这是植物适应性生长的重要机制之一。NO的主要生化功能之一是通过S-亚硝基化修饰调控相关靶蛋白的生物学活性。S-亚硝基化是一种基于氧化还原、可逆的蛋白质翻译后性修饰机制，通过NO取代半胱氨酸残基的巯基基团的氢离子而形成共价键相连亚硝基硫醇（S-NO）而实现。NO调控防御反应与胁迫反应的机制有较系统的研究，但对其调控植物生长发育的机制知之甚少。我们前期的研究发现NO负调控细胞分裂素反应，并与NO诱导的细胞分裂素信号通路中主要组分的S-亚硝基化修饰直接相关。在本研究中，我们拟通过多种途径探索S-亚硝基化修饰调控拟南芥细胞分裂素信号通路主要组分生物学活性的生化机制和分子机制，揭示NO信号通路和细胞分裂素信号通路互作调控植物适应性生长的分子机理。

Adverse growth conditions usually induce the production of nitric oxide (NO), a critical signaling molecule that activates the stress and defense responses, and causes the growth delay or arrest. This represents an important adaptation growth mechanism in plants. The NO-regulated stress responses have been well documented. However, little is known about the mechanism of NO-regulated growth and development. In our previous studies, we found that NO negatively regulates cytokinin signaling, possibly by S-nitrosylation of key components in the cytokinin signaling pathway. In this applications, we propose to investigate the molecular mechanism and the physiological significance of the NO-repressed cytokinin signaling through S-nitrosylation, aimed at the understanding the mechanism by which NO signaling and cytokinin signaling coordinate plant growth and development.