我们最近发现，甲烷（CH4）可能是一种新的气体信号分子；生长素能诱导黄瓜外植体下胚轴基部CH4的产生，模拟内源CH4释放的富甲烷水通过调节生长素应答基因以及细胞循环周期基因表达来诱导不定根发生，一氧化氮（NO）可能是其下游的信号分子。为了探查相关作用机制，本课题首先从活性氧和甲硫氨酸两个方面探查生长素诱导的CH4生物合成途径及其与不定根发生的关系，分析受CH4调控的黄瓜不定根发生过程中NO来源以及时空变化，结合采用清除剂以及抑制剂，比较细胞循环周期基因以及不定根原基/不定根发生的差异，明确CH4诱导的NO与不定根发生的关系；采用位点专一性的亚硝基蛋白质组学方法鉴定NO介导的S-亚硝基化蛋白种类和氨基酸靶点，从而以NO信号转导为重点探查CH4调控不定根发生的下游关键蛋白、信号通路以及与生长素信号途径的关系。上述结果不仅提供植物CH4生物学效应的证据，同时也为开发新的生长调节剂提供初步的知识。

Our recent results showed that methane (CH4) might be a new gaseous signal molecule. For example, auxin was able to stimulate CH4 releasing in cucumber explants. The application of methane-rich water (MRW) not only mimicked the releasing of endogenous CH4, but also triggered cucumber adventitious rooting. The involvement of auxin signaling related genes and cell cycle regulatory genes was also suggested. Further results revealed that nitric oxide (NO) might be the downstream molecular in this event. To explore this possibility, in this project, the possbility of reactive oxygen species (ROS)- and methionine (Met)-mediated auxin-triggered CH4 production and corresponding relationship with adventitious rooting were investigated in cucumber explants. The enzymatic- and non-enzymatic resources of NO synthesis in CH4-mediated process were also analyzed. By using electron spin resonance (ESR) and laser scanning confocal microscope (LSCM), combined with the application of the NO donors, scavenger and possible synthetic inhibitors, the spatial/temporal of NO distribution/content, the transcripts of cell cycle regulatory genes, as well as the changes of adventitious root primordia and adventitious root formation, were compared. The classification of S-nitrosylated proteins and the identification of the S-nitrosylated cysteine residues were also carred out with site-specific S-nitrosoproteomic approach. Therefore, the downstream components and signal transduction pathway (especially related to NO), and its relationship with auxin signaling were summarized. These results would not only provide the knowledge of biological roles of CH4 in plants, but also provide theoretical basis for the development of new crop growth regulators.