褐飞虱（BPH）是水稻主要害虫之一，严重危害农业生产。我们发现：沉默水稻5羟色胺（Serotonin）合成酶基因OsT5H可对BPH产生抗性，外施此化合物则吸引BPH取食。同时，BPH侵害可诱导其表达上升，以获取更多的5羟色胺；但防御响应分子水杨酸（Salicylic acid, SA）处理可显著抑制其表达。由此推测，OsT5H启动子存在着响应BPH侵害诱导及SA抑制的重要元件，两者竞争性调控其表达。本项目旨在对其启动子的响应元件进行鉴定。从两条途径展开：一是大范围上，通过启动子截短实验确定响应BPH诱导和SA抑制的区段；二是小范围内，探究序列多态性和OsT5H的表达关系。我们对核心种质533份材料的OsT5H启动子测序发现，其有着丰富的多态性位点，共有16种单倍型，可进一步分析局部变异位点对表达水平的影响。通过上述两种筛选模式，找出叠加区域，有望解析出关键的应答元件。

The brown planthopper (BPH) is one of the major rice insect pest and can severely affect rice production, causing yield losses. Our study revealed that: silencing or knocking out serotonin synthesis gene OsT5H can enhance the resistance of rice plants to BPH. Furthermore, we also observed that BPH infestation induce expression of OsT5H and SA synthesis related genes, whereas SA treatment can significantly inhibit the transcription of OsT5H. Therefore, we suggest that there are two kinds of elements in the promoter of OsT5H that are responsive to BPH infestation (Inducer) and SA treatment (Inhibitor), respectively. To identify these elements, two approaches will be deployed. Firstly, heterologous GUS gene driven with truncated OsT5H promoter (∆OsT5H::OsT5H-GUS) will be constructed and transformed into rice. The transgenic rice plants will be subjected to BPH infestation and SA treatment, and GUS staining will be tested to identify responsive elements. Secondly, a core rice germplasm collection (533 lines) with 16 haplotypes of the OsT5H promoter will be used for association analysis of OsT5H expression and its response to BPH infestation and SA treatments, and thus identify the responsive haplotypes and key elements of the promoter. At last, the responsive elements will be validated through genome editing using the CRISPR technology. The findings of this project will provide new approaches for generation and breeding of BPH resistant rice.