滇黄精PkSVP基因响应低温调控初生根茎芽休眠的功能机制

滇黄精是我国传统药食同源的中药材，但在其初生根茎发育的早期阶段存在严重的根茎芽休眠现象，阻碍了滇黄精有性繁殖进程，不利于滇黄精资源可持续发展，因此本研究对滇黄精初生根茎芽休眠解除的分子机制进行探究。本项目基于前期研究基础，锁定关键基因PkSVP,构建滇黄精PkSVP过表达和RNA沉默型，分析滇黄精野生型及PkSVP过表达型萌芽表型等特征对低温的响应差异，对PkSVP响应低温调控滇黄精初生根茎芽休眠进行功能鉴定；对滇黄精野生型及PkSVP过表达型进行转录组测序，进行差异基因共表达分析；克隆PkSVP启动子序列，进行启动子序列分析，联合RNA-Seq分析结果，预测PkSVP上游转录因子；Y1H和EMSA实验验证候选转录因子和PkSVP启动子的结合。本项目对阐明滇黄精休眠解除分子机制具有重要意义，为黄精快速育苗和种源技术攻关奠定基础，有利于推进黄精生物工程育种产业化实现。

Polygonatum kingianum is a kind of medicinal and edible traditional Chinese medicine, however, several factors can inhibit the production of P. kingianum following seed germination. One of these issues derives from the stages of early rhizome development, wherein the young germinated seed quickly develops a small rhizome that enters a prolonged state of bud dormancy, which is harmful to sustainable development of Polygonatum resources, therefore, the molecular mechanism of P. kingianum rhizome bud dormancy release was explored in this study, so as to lay a foundation for the breed improvement of P. kingianum. Based on our previous studies, the key gene PkSVP was targeted in this project. To identify PkSVP function in responsing rhizome bud dormancy regulated by low temperature, overexpression and RNA interference of PkSVP were constructed in P. kingianum and responses of germinating phenotype to low temperature were compared among wild, OE-PkSVP and PkSVPRNAi type. Transcriptome sequencing was performed on wild and OE-PkSVP type to carry out co-expression analysis for differentially expressed genes in response to low temperature. PkSVP promoter was cloned and cis-acting elements of the promoter were analyzed. Combined with RNA-Seq analysis, the upstream transcription factors of PkSVP were predicted. Y1H and EMSA assay were carried out to verify the binding of predicted transcription factor to PkSVP promoter. This project reveals molecular mechanism for dormancy release of P. kingianum rhizome bud and lays a foundation for rapid seedling, furthermore, it exploit genetic resources for P. kingianum, which are beneficial to realize the industrialization of Polygonatum bioengineering breeding.