大白菜作为重要的蔬菜作物，其花期调控机理研究有重要理论意义和应用价值；FLC是植物开花核心抑制因子；H2S是继NO、CO之后第三种气体信号分子，在植物中的重要生理功能日渐引起重视；半胱氨酸脱巯基酶LCD是内源H2S生成的关键酶。我们已证实大白菜开花明显受生理浓度H2S诱导；其4个BraFLCs同源基因功能有分化；体外实验发现生理浓度H2S可以对部分BraFLCs成员进行特异性硫巯基化修饰，从而调节它们与下游靶序列的结合模式。这就提出一种通过BraFLCs翻译后修饰调控大白菜开花的全新机制。我们拟在此基础上从遗传学、生物化学和分子生物学多个层次系统深入地对这些现象进行研究，提供更全面的实验证据。本项目的开展提出了信号分子H2S新的作用靶点，拓展了FLC新的功能调节方式，也为大白菜多拷贝同源基因功能分化提供了新证据，最终解释了H2S促进大白菜开花的分子机制，为大白菜花期调节提供新的思路和途径。

Chinese Cabbage (Brassica rapa L. ssp. pekinesis) is one of the favorite vegetables in China. Its flowering regulation is a hot research topic. And FLC is the core inhibitor of flowering in plants. Hydrogen sulfide (H2S) has been proposed as the third gasotransmitter after nitric oxide and carbon monoxide, whose physiological functions in mammals have been fully confirmed, thus making it a hot research area. In recent years, great improvement has also been achieved with respect to the studies on H2S function in plants. LCD (L-cysteine desulphydrase) is a key enzyme to generate endogenous H2S in plants. We have confirmed that H2S at physiological concentration promoted the flowering significantly in Chinese cabbage; The function of the four duplicated BraFLCs homologous were diversification. Experiments In vitro showed that H2S at physiological concentration could modify some members of BraFLCs by S-sulfhydrylation, thus regulating their binding patterns to downstream target sequences. This suggested a new mechanism for regulating flowering through post-translational modification of BraFLCs in Chinese cabbage. On this basis, we intend to study these mechanism systematically in genetics, biochemistry and molecular biology, to provide more comprehensive experimental evidences. This project will propose a new molecular target of H2S, expand the new regulation way of FLC, and provided new evidences for functional diversification of multicopy homologous genes in Chinese cabbage. Based on the above data, the molecular mechanism of H2S promoting flowering in Chinese cabbage will be revealed. It will provide a new idea and way for the regulation of flowering period of Chinese cabbage.