title: Newly mutated putative-aminotransferase in nonpungent pepper (Capsicum annuum) results in biosynthesis of capsinoids, capsaicinoid analogues.
abstract: Capsinoids make up a group of nonpungent capsaicinoid analogues produced in Capsicum fruits. They have bioactivities similar to those of capsaicinoids such as suppression of fat accumulation and antioxidant activity. Because of their low pungency, they are more palatable ingredients in dietary supplements than capsaicinoids. We recently reported that capsinoid biosynthesis is caused by nonsense mutation in a putative aminotransferase gene (p-AMT) in a nonpungent cultivar CH-19 Sweet. Here we report on the screening of nonpungent germplasm that revealed a nonpungent cultivar Himo, which contains high levels of capsinoids. We have shown that Himo has a recessive allele of p-amt, which contains a mutation different from that of CH-19 Sweet. Sequence analysis of p-amt in Himo revealed that a single-nucleotide substitution results in one amino acid substitution from cysteine to arginine in the pyridoxal 5-phosphate binding domain. Genetic analysis using a cleaved amplified polymorphic sequence marker confirmed that the p-AMT genotype was precisely cosegregated with capsinoid biosynthesis and nonpungency. Himo will provide a new natural source of capsinoids.
authors.affiliation: Graduate School of Agriculture, Kyoto University, Oiwake-cho, Kitashirakawa, Kyoto 606-8502, Japan.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Munetaka
authors.initials: M
authors.lastname: Hosokawa
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Miwa
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Watanabe
authors.forename: Susumu
authors.initials: S
authors.lastname: Yazawa
mesh_terms: D000470:Alkaloids / Q000096:biosynthesis*; D000595:Amino Acid Sequence; D002212:Capsicum / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D016415:Sequence Alignment; D000637:Transaminases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism
chemical_list: D000470:Alkaloids; D010940:Plant Proteins; D000637:Transaminases