番茄USP1响应干旱和高温胁迫的研究

DDB1作为CUL4泛素连接酶的核心组件参与细胞内许多重要的生命活动。前期研究发现番茄CUL4-DDB1复合物（CRL4）调节植物细胞的非生物胁迫应答。为进一步阐明DDB1在植物抗逆中的调控机制和生理功能，通过酵母双杂交筛选，发现普遍应激蛋白USP1与DDB1存在相互作用， USPs家族蛋白参与提高生物体对逆境胁迫的耐受；进一步研究发现USP1定位于细胞质中，且其基因表达受到多种胁迫条件诱导。此外泛素化实验揭示USP1可以被泛素化修饰降解，上调USP1表达导致植株对干旱和高温抗性的增强，表明USP1可能正调控番茄植株对逆境下胁迫的应答，且它的作用受CUL4-DDB1泛素连接酶的靶向降解调控。结果不仅揭示新的植物抗逆机理，而且为植物抗逆分子育种提供新的基因资源和技术途径。

Study on tomato USP1 in response to drought and high temperature stress

As the core component of CUL4 ubiquitin ligase, DDB1 participates in many important biological processes. Our previous study found that tomato CUL4-DDB1 complex regulates abiotic stress response. In order to further clarify the regulatory mechanism and physiological function of DDB1 in plant stress resistance, we found that USP1 interacted with DDB1 through yeast two hybrid screening, and USPs family proteins were involved in improving the tolerance of organisms to stress. Further studies found that USP1 was located in the cytoplasm, and its gene expression was induced by a variety of stress conditions. In addition, ubiquitination experiments revealed that USP1 could be degraded by ubiquitination modification, and upregulation of USP1 expression led to the enhancement of plant resistance to drought and high temperature, indicating that USP1 may regulate tomato plant response to stress, and its role is regulated by the targeted degradation of CUL4-DDB1 ubiquitin ligase. The result not only reveal new mechanisms of plant stress resistance, but also provide new gene resources and technical approaches for plant stress resistance molecular breeding.