菜心是我国华南地区栽培的特色蔬菜之一。菜心采后贮运期间，茎部容易木质化，严重影响其营养品质及商品价值。前期研究发现，高氧处理可明显延缓菜心木质素积累、H2O2的产生及木质素合成关键酶活性的提高，下调苯丙烷途径和木质素特异途径相关酶基因的表达，并发现WRKY转录因子在MAPK信号级联途径中差异表达。基于此，本项目拟对WRKY对菜心采后木质化的调控机制进行深入研究。（1）通过转录组测序及生物信息学分析筛选可能对木质素合成起调控作用的WRKY转录因子。（2）利用酵母单杂交、ChIP-Seq、EMSA等方法分析WRKY下游靶基因；并采用酵母双杂交，BiFC等筛选WRKY的互作蛋白，解析其调控网络。（3）通过超表达及RNA干扰验证WRKY参与采后菜心木质素化的调控功能。该研究有助于明确菜心木质化品质劣变的机理；并为探索菜心采后保鲜技术提供理论参考。

Chinese cabbage (Brassica campestris L. ssp. chinensis Makino) is one of the most cultivated vegetables for its edible stem and leaf in South China. However, the lignification of its stem during storage has become a serious problem for its quality and marketable value. In our previous study, high-oxygen modified atmosphere packaging (HO-MAP) treatment could effectively delay the accumulation of lignin, reduce the activity of key enzymes involved in lignin biosynthesis, and retard the production of H2O2, as compared to air packaging (AP). Furthermore, the relative expression levels of genes involved in lignin biosynthesis were inhibited, the WRKY transcription factors (TFs) in MAPK signal pathway were also found to be regulated. Therefore, the goal of this proposed project is to address the mechanism of WRKY TFs regulating on the lignification of Chinese cabbage during storage. We hypothesize that the WRKY TFs may regulate the lignification of Chinese cabbage directly interacting with the promoter of target genes, and/or through MAPK pathway to influence the ROS production during storage. (1) RNA sequencing is employed to screen the potential WRKY TFs, which may take part in regulating the lignification process after the Chinese cabbage were treated by HO-MAP and AP during storage. (2) Multiple molecular techniques such as Yeast 1/2 hybrid, EMSA, dual luciferase assay, ChIP-Seq, and BiFC etc., will be applied to investigate the characteristics of regulation attributes of WRKY TFs to the target genes involved in lignin biosynthesis and ROS metabolism process. In addition to the interactions between WRKY TFs and the target genes, other proteins i.e., MAPK members, which may interact with WRKY TFs to co-function on regulating the production of ROS, thus, influencing the lignification process are also going to be conducted. (3) To further verify the function of candidate WRKY TFs, over-expression and RNA interference will be manipulated. The results obtained from this proposed project are hopefully to help illustrate the mechanisms of WRKY TFs regulating on lignification of Chinese cabbage during storage; and to provide guidance for developing possible techniques to delay the shelf life.