Abstract:

Capsaicin is most important quality trait in the fruits of pepper and has been widely applied to food, medicine and industry. Capsaicin synthase(CS) is recognized as a key enzyme regulating the process of capsaicin. Basing on the sequences of capsacin synthase gene csy1 known at Genbank, in this article the primers were designed to clone a fragment csy-h from Huangdenglong pepper by RT-PCR. Analysis of sequences showed that csy-h had shared the 98% homologous to csy1 gene known at Genbank, 100% homologous at protein sequences each other. Expression identified that csy-h expressed at placenta tissue of pepper fruits with increasly firstly, then decreased. Reseach on activity of CS and content of capsaicin indicated that CS activity at placenta and content of capsaicin and dihydrocapsaicin decreased after increased respectly, with the peak of 35 days after flowering at the former and 42 days after flowering in the latter. Above results showed that the level of csy1 expression determined the activity of CS which dedicated the content of capsaicin and dihydrocapsaicin.