Investigation of Genetic Factors Controlling Capsiate Biosynthesis in Pepper

Abstract

Capsinoid which were found recently in non-pungent pepper show the same biological effects as capsaicinoid including anticancer and anti-obesity. A precursor of capsinoid, vanillyl alcohol, is known to be produced by mutations in the putative-aminotransferase (pAMT) gene. In the previous study, it was reported that capsinoid production is also controlled by the capsaicin synthase (CS) gene. However the relation between the CS activity and capsinoid contents has not been fully understood. This study was conducted to elucidate the role of CS in quantitative control of capsinoid contents. In the previous study, C. chinense, SNU11-001, which contains capsinoid higher than C. annuum CH-19 Sweet was identified. Non-functional mRNA of SNU11-001 had stop codon resulted from 403bp insertion and 45bp deletion. I analyzed the CS and pAMT activity using the five Capsicum accessions containing different levels of pungency including SNU11-001, the transcription levels of CS were higher in pungent Capsicum accessions. Molecular markers which can distinguish CS and pAMT genotype between SNU11-001 and pungent pepper cultivar Habanero were developed. To investigate SNU11-001 x Habanero F2 population was constructed and analyzed correlation between capsaicinoid and capsinoid concentration and CS genotypes of SNU11-001 and Habanero. Therefore, CS genotype of SNU11-001 and Habanero did not have influence on quantitative trait of capsinoid. Genetic factor which is not related in capsaicinoid biosynthesis might exist quantitative control of capsinoid synthesis. Transcriptome analysis between Capsicum pepper with capsinoid and pungent cultivar will identify effect on regulation of capsinoid contents in future studies.