Premium
Gene expression in flavonoid biosynthesis: Correlation with flavonoid accumulation in developing citrus fruit
Author(s) -
Moriguchi Takaya,
Kita Masayuki,
Tomono Yasuhiko,
EndoInagaki Tomoko,
Omura Mitsuo
Publication year - 2001
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1034/j.1399-3054.2001.1110109.x
Subject(s) - flavonoid , flavonoid biosynthesis , chalcone isomerase , biology , chalcone synthase , gene , flavanone , complementary dna , gene expression , biochemistry , cdna library , transcriptome , antioxidant
Two genes active in the early steps of flavonoid biosynthesis were isolated from a citrus cDNA library, and their expression patterns were analyzed during citrus ( Citrus unshiu Marc.) fruit development in relation to flavonoid contents. The respective cDNA clones from chalcone isomerase (CHI, CitCHI) and flavanone 3‐hydroxylase (F3H, CitF3H) are 931 and 1360 bp long, encoding 222 and 362 amino acid residues. CitCHI seems to be a single‐copy gene, whereas a few CitF3H‐related sequences are present in the citrus genome. Messenger RNA levels of the flavonoid biosynthetic genes CitCHI and CitF3H and two previously isolated chalcone synthases (CHS, CitCHS1, and CitCHS2) were analyzed in various tissues during fruit development. Transcript levels for CitCHS1, CitCHS2, CitCHI, and CitF3H were generally high in young tissues and low in senescent tissues. Flavonoid changes were analyzed in relation to gene expression. High flavonoid contents were found in young tissues. The high expression of flavonoid biosynthetic genes and high accumulation of flavonoids in young fruits suggest that flavonoids are synthesized in the early developmental stage.