辣椒素是只在辣椒属植物中合成的辣味物质，是辣椒果实品质重要性状，需求缺口高达80%。目前，辣椒素生物合成途径关键基因基本阐明，且其在胎座中的表达量和辣味显著正相关，但是转录调控机制尚不清楚。我们的前期研究已经发现7个在胎座中显著上调或特异表达的MYB转录因子，该转录因子和其它植物中参与次生代谢的MYB转录因子具有较高的同源性，暗示这些转录因子可能参与辣椒素生物合成的转录调控。本项目拟深入研究7个MYB转录因子在辣椒素生物合成中的功能。分析MYB在不同辣度材料中的表达模式；分析VIGS沉默、CRISPR-Cas9基因敲除和超表达MYB转录因子对辣椒素合成的影响；用酵母单杂交和ChIP法分析MYB在辣椒素合成酶关键基因启动子上的结合位点；用酵母双杂交和BiFC法找到与转录因子互作蛋白。研究结果将阐明MYB转录因子调控辣椒素生物合成的分子机制，为辣椒果实辣椒素含量分子改良和调控奠定基础。

Capsaicin and its analogues, collectively called capsaicinoids are the pungent principle of peppers, which strictly biosynthesis in Capsicumis, an important constituent of fruit quality. The capsaicin demand gap is as high as 80% above in the world. To date, the enzyme genes involved incapsaicin biosynthesis have been elucidated, which showedtheirexpression levelswereconsistent with capsaicinoids contents. But the transcriptional regulation mechanism of capsaicin biosyntheticgenes is still largelyunknown. In our previous study, ranscriptome sequencing and qRT-PCR revealed that the expression levels of seven MYB TFs were significantly up-regulated or specifically expressed in placenta, and phylogenetic analysis showed that these transcription factors (TFs) share high homology with the MYB TFs involved in secondary metabolism from other plant species, suggesting that these TFs may play important roles in transcriptional regulation of capsaicinoids biosynthesis . In this study, the regulation mechanism of MYB TFs on capsaicin biosynthesis will be investigated. Firstly, the expression patterns of these MYB TFs will be analyzedinvarieties with differentpungency levels. Secondly, the roles of sevenTFs involved in capsaicin biosynthesis will be investigated in chili pepper by virus-induced gene silencing (VIGS), CRISPR-Cas9 and gene overexpression in chili pepper. Thirdly, yeast one-hybrid(Y1H) and chromatin immunoprecipitation(ChIP) are used to analyze the MYB TFs binding topromoters of MYB binding site (MBS) of capsaicin biosynthesis genes.In addition, yeast tow-hybrid (Y2H) and bimolecular fluorescence complementation (BiFC) were used to find key proteins interacted with MYB TFs proteins.The results from this work will help to uncover the regulation mechanisms of these MYB TFs on capsaicin biosynthesis, and consequently provide a basis for the generation of different pepper cultivars with expected fruit pungency levels by genetic engineering and breeding.