辣椒是世界范围内重要的经济蔬菜,含有对其发展和风味至关重要的各种特殊代谢产物。辣椒素类,尤其是,是属专门的代谢产物,赋予辣椒果实辛辣的味道。在这项工作中,两个辣椒品种,YB(辣椒)和JC(辣椒)胡椒,辣椒素和类黄酮的积累有明显差异。然而,它们的分子机制尚不清楚.代谢组分析表明,JC辣椒诱导了更丰富的与生物碱相关的代谢产物积累,黄酮类化合物,和辣椒素在红色成熟阶段,导致JC胡椒粉更辛辣的味道。转录组分析证实,与类苯丙烷和类黄酮代谢途径相关的转录物表达增加发生在JC辣椒中。代谢组和转录组的整合分析表明,四个结构基因,4CL7,4CL6,CHS,和COMT,与辣椒素和类黄酮相关的代谢物积累较高。通过加权基因共表达网络分析,确定了与类黄酮生物合成相关的模块和候选基因的潜在调节因子。四个候选基因的启动子分析表明它们含有几个与MYB结合的顺式元件,bZIP,和WRKY转录因子。进一步RT-qPCR检测验证了三个转录因子,MYB,与YB相比,bZIP53和WRKY25在JC辣椒的红色成熟阶段表现出增加的表达,这可能会调节它们的表达。总之,我们的研究结果为今后的辣椒育种计划提供了全面的了解和有价值的信息。
Pepper is an economically important vegetable worldwide, containing various specialized metabolites crucial for its development and flavor. Capsaicinoids, especially, are genus-specialized metabolites that confer a spicy flavor to Capsicum fruits. In this work, two
pepper cultivars, YB (Capsicum frutescens L.) and JC (Capsicum baccatum L.)
pepper, showed distinct differences in the accumulation of capsaicin and flavonoid. However, the molecular mechanism underlying them was still unclear. Metabolome analysis showed that the JC
pepper induced a more abundant accumulation of metabolites associated with alkaloids, flavonoids, and capsaicinoids in the red ripening stages, leading to a spicier flavor in the JC pepper. Transcriptome analysis confirmed that the increased expression of transcripts associated with phenylpropanoid and flavonoid metabolic pathways occurred in the JC
pepper. Integrative analysis of metabolome and transcriptome suggested that four structural genes, 4CL7, 4CL6, CHS, and COMT, were responsible for the higher accumulation of metabolites relevant to capsaicin and flavonoids. Through weighted gene co-expression network analyses, modules related to flavonoid biosynthesis and potential regulators for candidate genes were identified. The promoter analysis of four candidate genes showed they contained several cis-elements that were bonded to MYB, bZIP, and WRKY transcription factors. Further RT-qPCR examination verified three transcription factors, MYB, bZIP53, and WRKY25, that exhibited increased expression in the red ripening stage of the JC pepper compared to YB, which potentially regulated their expression. Altogether, our findings provide comprehensive understanding and valuable information for
pepper breeding programs in the future.