芝麻素合成调控基因的鉴定与功能验证

Sesamin is a unique biological active substance in sesame seeds, with antioxidant, blood pressure reducing, anti-inflammatory, cancer-combating and other health functions. However, the molecular mechanism of the sesamin biosynthesis of sesame seeds still remain unclear, which limits the progress of the genetic improvement of sesamin in sesame seeds. Genome-wide association analysis (GWAS) combining with whole-genome wide linkage mapping is an effective strategy for rapidly and accurately locating genes related to complex quantitative traits, which can significantly improve the efficiency of gene identification. The core collection containing 705 sesame samples was selected from more than 7000 basic sesame germplasm resources and were resequenced. GWAS of sesamin content was performed and 6 significantly associated sites were identified. One sample with super high sesamin content and one sample with extremely low sesamin content were selected from the basic sesame germplasm resources. And one RIL population was constructed from the cross of the two samples. Proposed on the basis of the preliminary work, the RIL population will be resequenced and transcritome sequencing of the developing seeds of the parents of the RIL population will be performed. Based on the GWAS results, QTL mapping results, gene expression information and gene annotation, the candidate gene of sesamin biosynthesis will be identified. Then the gene function will be validated by sesame genetic transformation experiments and closely linked molecular markers will be developed. The results will provides theoretical basis and technical support for the genetic improvement of sesamin content in sesame seeds.

芝麻素是芝麻特有的生理活性成分，具有抗氧化、降血压、抗炎、抗癌等多种健康功能，但是芝麻素合成的分子基础不清，限制了芝麻素遗传改良的进程。全基因组关联分析结合连锁作图是快速、准确定位复杂数量性状基因的有效策略，可显著提高基因定位的效率。本项目前期通过逐级筛选从芝麻基础收集品中建立了包含705材料的芝麻核心种质，采用全基因组关联分析发掘到6个芝麻素含量显著关联位点，还利用发掘到的芝麻素含量特异种质构建了RIL群体。拟在前期工作基础上，对RIL群体进行全基因组重测序，通过全基因组连锁分析定位与芝麻素含量紧密连锁的QTL位点，并对RIL群体亲本进行种子发育转录组测序，获得基因表达信息，结合关联分析、连锁分析、基因表达和功能注释等信息，鉴定芝麻素合成调控的关键基因，进一步通过芝麻遗传转化验证基因功能，并开发分子标记，为芝麻素遗传改良提供理论基础和技术支持。

芝麻素是芝麻特有的生理活性成分，具有抗氧化、降血压、抗炎、抗癌等多种健康功能，但是芝麻素合成的分子基础不清，限制了芝麻素遗传改良的进程。全基因组关联分析结合连锁作图是快速、准确定位复杂数量性状基因的有效策略，可显著提高基因定位的效率。本项目前期通过逐级筛选从芝麻基础收集品中建立了芝麻核心种质，采用全基因组关联分析发掘到芝麻素含量显著关联位点，还利用发掘到的芝麻素含量特异种质构建了RIL群体。在前期工作基础上，我们对RIL群体进行全基因组重测序，并对RIL群体亲本进行种子发育转录组测序和芝麻素相关物质测定，发掘芝麻素合成调控的重要基因。此外，还对芝麻抗旱、开花、油酸含量等重要农艺性状相关的基因进行了发掘，获得了一批候选基因，并对其中2个基因进行了转基因验证。本研究将为芝麻的遗传改良提供重要基因资源和技术支持。