草莓HY5基因功能鉴定及调控磷含量机制的研究

磷是植物生长发育必需的大量元素之一。前期研究我们发现提高磷肥供应能提高草莓果实品质，并解析了森林草莓中多个参与磷信号基因（PHR1/PHO1/PHO2/MIR399）的功能，发现这些基因启动子中均包含HY5转录因子的结合位点。申请者通过森林草莓稳定遗传转化获得HY5过表达草莓植株，发现在磷充足条件下，HY5的过表达能降低试管苗磷含量。但是HY5怎样调控草莓植株磷含量，在高磷和低磷条件下其作用是否一致，仍需要解析。本项目拟进一步开展草莓HY5基因功能鉴定研究。获得HY5基因编辑草莓植株后，在高磷和低磷条件下，调查分析HY5过表达、基因编辑植株的表型、磷含量及其果实品质的差异，利用转录组和ChIP-seq技术筛选HY5下游参与磷调控的候选靶基因。通过上述研究，探索HY5对草莓磷含量的调控机制，为通过栽培和育种途径提高草莓植株对磷的利用效率奠定基础。

Phosphorus is one of the essential elements for plant growth and development. In previous studies, it was found that increasing the supply of phosphate fertilizer could improve the sugar content of strawberry fruits. the functions of several genes（PHR1/PHO1/PHO2/MIR399） involved in Pi signal in woodland strawberry were analyzed, and we found that contain HY5 binding site in the promoters of these genes. The HY5-overexpressing strawberry was obtained by using Agrobacterium-mediated strawberry transformation procedure. It was found that the Overexpression of FvPHR1 reduce P content in strawberry test-tube plantlets under Pi-sufficient conditions. However, how HY5 regulates phosphorus content in strawberry plants through regulating phosphorus starvation response genes, and whether these effects are consistent under high phosphorus and low phosphorus conditions remains to be determined. This project intends to further study the function of FvHY5 in strawberry. After HY5 gene editing strawberry were obtained, we need observe and analyse the differences from the phenotype, phosphorus content and fruit quality in HY5 gene knockout and HY5-overespressing strawberry under high phosphorus and low phosphorus conditions. transcriptome and ChIP-Seq technology were used to screen candidate target genes downstream of HY5 involved in phosphorus regulation. In this study, we explore the regulation mechanism of HY5 on strawberry phosphorus content, and this laid a foundation for improving phosphorus utilization efficiency of strawberry plants through cultivation and breeding.