柱花草是重要的热带亚热带豆科牧草，炭疽病是威胁其生产的主要病害。苯丙氨酸解氨酶（PAL）是苯丙烷次生代谢途径的第一个关键酶和限速酶，但PAL在植物抗炭疽病过程中发挥的功能与调控机制仍不清楚。前期工作中通过RNA-seq分析鉴定到1个受炭疽菌诱导表达的柱花草苯丙氨酸解氨酶基因SgPAL1，超量表达该基因显著增强柱花草对炭疽病的抗性。在此基础上，本项目将对转基因柱花草开展代谢组学分析，明确SgPAL1介导次生代谢途径参与柱花草抗炭疽病的作用机理；利用酵母单杂交等方法鉴定调控SgPAL1的上游转录因子并分析其功能，解析SgPAL1的转录调控网络；通过质谱技术鉴定SgPAL1蛋白的翻译后修饰位点，并分析位点突变对SgPAL1生化酶学性质和蛋白转运的影响，揭示翻译后修饰对SgPAL1的调控作用。研究结果将阐明SgPAL1参与柱花草抗炭疽病的分子机制，并为柱花草抗病品种选育提供理论依据和候选基因资源。

Anthracnose caused by Colletotrichum gloeosporioides is one of the most destructive fungal diseases of stylo (Stylosanthes spp.), which is an important tropical forage legume. Phenylalanine ammonia lyase (PAL) is the first key enzyme and speed limiting enzyme in the secondary metabolite pathway of the phenylpropane. However, little information about the function of PAL in plant defense against pathogen is available. In our previous study, the expression of SgPAL1 was increased by C. gloeosporioides treatment in stylo leaves. Overexpression of SgPAL1 in Agrobacterium-mediated transformed stylo increased the resistance of it against anthracnose. In this study, we plan to elucidate the mechanism of stylo resistance to anthracnose through secondary metabolite pathway regulated by SgPAL1. To dissect the transcriptional regulatory network of SgPAL1, the transcription factor of SgPAL1 will be analyzed using yeast one-hybrid system. To reveal the post-translational modification on the regulation of SgPAL1, the critical sites of SgPAL1 on biochemical properties and protein transportation will be studied. Our results could not only dissect the molecular mechanisms of SgPAL1 in stylo against anthracnose, but also provide theoretical base and candidate gene for breeding stylo cultivar with anthracnose resistance.