Molecular identification of 1-Cys peroxiredoxin and anthocyanidin/flavonol 3-O-galactosyltransferase from proanthocyanidin-rich young fruits of persimmon (Diospyros kaki Thunb.).
Fruits of persimmon (Diospyros kaki Thunb.) accumulate large amounts of proanthocyanidins (PAs) in the early stages of development. Astringent (A)-type fruits remain rich in soluble PAs even after they reach full-mature stage, whereas non-astringent (NA)-type fruits lose these compounds before full maturation. As a first step to elucidate the mechanism of PA accumulation in this non-model species, we used suppression subtractive hybridization to identify transcripts accumulating differently in young fruits of A- and NA-type. Interestingly, only a few clones involved in PA biosynthesis were identified in A-NA libraries. Represented by multiple clones were those encoding a novel 1-Cys peroxiredoxin and a new member of family 1 glycosyltransferases. Quantitative RT-PCR analyses confirmed correlation of the amount of PAs and accumulation of transcripts encoding these proteins in young persimmon fruits. Furthermore, the new family 1 glycosyltransferase was produced in Escherichia coli and shown to efficiently catalyze galactosylation at 3-hydroxyl groups of several anthocyanidins and flavonols. These findings suggest a complex mechanism of PA accumulation in persimmon fruits.
Ikegami
Ayako
A
Laboratory of Pomology, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan.
Akagi
Takashi
T
Potter
Daniel
D
Yamada
Masahiko
M
Sato
Akihiko
A
Yonemori
Keizo
K
Kitajima
Akira
A
Inoue
Kentaro
K
D000595:Amino Acid Sequence; D000872:Anthocyanins / Q000737:chemistry / Q000378:metabolism*; D055162:Biocatalysis; D002999:Clone Cells; D029788:Diospyros / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D044948:Flavonols / Q000737:chemistry / Q000378:metabolism; D005638:Fruit / Q000201:enzymology* / Q000254:growth & development*; D005700:Galactosyltransferases / Q000737:chemistry / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D006031:Glycosylation; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D054464:Peroxiredoxins / Q000737:chemistry / Q000378:metabolism*; D010802:Phylogeny; D044945:Proanthocyanidins / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015203:Reproducibility of Results; D020133:Reverse Transcriptase Polymerase Chain Reaction; D020539:Sequence Analysis, Protein; D017386:Sequence Homology, Amino Acid
D000872:Anthocyanins; D044948:Flavonols; D044945:Proanthocyanidins; D012333:RNA, Messenger; C013221:proanthocyanidin; D054464:Peroxiredoxins; D005700:Galactosyltransferases