萝卜耐盐性关键基因鉴定与生物学功能分析

萝卜是起源于我国的重要根菜类蔬菜，土壤次生盐渍化严重制约了萝卜肉质根的产量和品质。提高萝卜品种的耐盐性、选育高耐盐的品种已成为当前蔬菜遗传改良领域的重要课题。本项目在成功进行萝卜耐盐性基因型筛选的基础上，以耐盐性差异显著的高代自交系为材料，拟利用基于转录组测序的数字基因表达谱(DGE)技术分离鉴定萝卜盐胁迫响应相关差异基因；对所测得的转录组和miRNA数据进行关联分析，鉴定萝卜耐盐性关键候选基因，并利用RT-qPCR技术分析其时空表达特征；通过基于Gateway体系的过表达技术和能高效引起体内靶基因沉默的人工microRNA(amiRNA)技术，验证耐盐性关键基因的生物学功能。本项目从转录水平、miRNA介导的转录后调控及基因功能验证等三个方面解析萝卜盐胁迫响应调控网络与耐盐性分子机制，研究结果将为萝卜耐盐性状遗传改良及种质创新提供重要理论基础。

Radish (Raphanus sativus L.) is an economically important root vegetable crop which originated in china. The secondary salinization in soil adversely affects the growth and development of the taproots in radish. Therefore, improving the salt tolerance of radish and developing highly salt-tolerant radish varieties would be a significant reseach work for current genetic improvement of vegetable crops. Based on successfully screening of elite radish genotypes of salt tolerance, in this project, the salt-responsive genes will be identified by digital gene expression profiling (DGE) technology using advanced inbred lines as materials which significantly exhibited difference in resistence to high salinity. Meanwhile, association analysis will be carried out between the transcriptome and miRNA expression profiling data obtained in our lab to identify key candidate genes involved in salt stress response. Furthermore, temporal and spatial expression profiles of these genes would be conducted with RT-qPCR. The biological functions of these key candidate genes will be validated by adopting Gateway system-based overexpression technique and artificial microRNAs (amiRNAs) which would silence the target gene efficiently. The regulatory network of salt stress response and molecular mechanism underlying the tolerance to salinity would be elucidated at the levels of transcription, miRNA-mediated post-transcriptional and from gene biological function validation. The results would provide an important theoretical foundation for genetic improvement of salt tolerance and germplasm enhancement in radish.