菌核病严重影响油菜产量和品质。理解菌核病抗病分子机制，是油菜抗病育种和保障我国粮油安全的需要。前期研究发现，菌核病抗性提高的spl突变体中H2O2异常积累，抗氧化酶活性升高、种子萌发的草酸敏感性降低、水杨酸途径基因激活，水杨酸含量增加。精细定位发现SPL可能为未知功能的类受体胞质激酶，菌核病诱导表达下调水平与菌核病抗性显著正相关。本项目中，我们将分析SPL的时空、诱导表达模式和亚细胞定位；以蛋白互作组和磷酸化蛋白组鉴定SPL互作底物蛋白及其关键磷酸化位点，构建以SPL为核心的磷酸化抗病信号转导网络；比较拟南芥单/双突变体，互补、过表达和RNAi等油菜植株的表型、生理指标和转录组，揭示SPL与底物蛋白互作和磷酸化修饰介导活性氧和水杨酸途径，以提高油菜菌核病抗性的分子机制。研究结果有助于完善植物免疫防御信号转导网络，为油菜及其近缘物种的抗病育种提供理论依据。

Sclerotinia sclerotiorum causes serious yield loss and quality reduction in rapeseed. Understanding the molecular mechanism of Sclerotinia sclerotiorum resistance is the precondition to develop disease-resistant varieties in rapeseed and guarantee the food and edible oil security in our country. In previous study, we identified a rapeseed spl mutant with significantly increased resistance to Sclerotinia sclerotiorum, which also shows over-accumulation of H2O2, higher antioxidase activity, and reduced oxalic acid sensitivity during seed germination. Besides, salicylic acid (SA) biosynthesis and signaling pathway genes were also activated, leading to significant increase of salicylic acid (SA) content. Fine mapping results revealed that SPL may encode a receptor like cytoplasmic kinase (RLCK) protein with unknown function, and its relatively down-regulated expression level is significantly positively correlated with Sclerotinia sclerotiorum resistance. To unravel the molecular basis of SPL functions, we propose to assess the spatio-temporal and induced expression patterns of SPL gene and subcellular location of SPL protein; to identify SPL interacting substrate proteins and their and their key phosphorylation sites, and construct a phosphorylation signaling network underlying disease resistance based on results of protein inter-actome and quantitative phosphoproteomics; to uncover the molecular mechanism of Sclerotinia sclerotiorum resistance enhanced by reactive oxygen species (ROS) and SA pathways, which regulated by interaction and phosphorylation between SPL and its interacting partners, according to comparison between single and double mutants in Arabidopsis thaliana, and that of phenotypes, physiological indexes, and transcriptomes among the complementary, overexpression and RNAi transgenic rapeseed lines. Our researches will provide insight into further understanding the plant immune signal transduction regulation network, lay a theoretical foundation for disease-resistant breeding in rapeseed and its relatives.