Why is pepper so hot?
Recently, Professor Lei Jianjun from the College of Horticulture of South China Agricultural University has made important progress in the transcriptional regulation and genetic evolution of capsaicinoid biosynthesis. Research results "Natural variations in the MYB transcription factor MYB31 determines the evolution of extremely pungent peppers" published in the internationally renowned academic journal "New Phytologist" (new botanist; Chinese Academy of Sciences, 5 years influencing factor: 7.83). The study found that MYB31 is a transcriptional regulator of capsaicinoid synthesis in Capsicum, and promoter mutations lead to the genetic evolution of the extremely spicy genotype pepper (C. chinense). This study can develop corresponding diagnostic molecular markers for the genetic improvement of pepper flavor.
The genes related to capsaicin synthesis pathway are present in tomato, potato and tobacco petunia of Solanaceae. The specific transcription of capsaicin synthesis related genes in the placenta of pepper is the reason why pepper produces spicy taste. Five of the 35 species of pepper are cultivated and domesticated. Capsicum chinense is extremely spicy (the content of capsaicin is extremely high), "Indian Devil's Pepper", "Calona Dead Pepper", "Spicy" And Hainan yellow bell peppers belong to this species. However, the capsaicin synthesis pathway-related gene (CBG) is specifically transcribed in Capsicum, and the genetic and molecular mechanisms of the formation of extremely spicy pepper are still unclear.
The study used the extremely spicy pepper (C. chinense) as the female parent, and the slightly spicy pepper (C. annuum) as the male parent to construct the interspecific hybrid population. The MYB transcription factor MYB31, which was cloned into the place of the fetus, directly regulates the genes involved in capsaicin synthesis. The MYB31 promoter variant is associated with transcriptional activity. MYB31 is strongly activated by WRKY9 in the highly spicy C. chinense material, which eventually leads to the formation of the extremely spicy C. chinense species.
