Differential expression of two flavonoid 3'-hydroxylase cDNAs involved in biosynthesis of anthocyanin pigments and 3-deoxyanthocyanidin phytoalexins in sorghum.
Three unique sorghum flavonoid 3'-hydroxylase (F3'H) cDNAs (SbF3'H1, SbF3'H2 and SbF3'H3) were discovered through bioinformatics analysis. Their encoded proteins showed >60% identity to the Arabidopsis TT7 (F3'H) protein. Overexpression of SbF3'H1 or SbF3'H2 restored the ability of tt7 mutants to produce 3'-hydroxylated flavonoids, establishing their roles as functional F3'H enzymes. In sorghum mesocotyls, SbF3'H1 expression was involved in light-specific anthocyanin accumulation while SbF3'H2 expression was involved in pathogen-specific 3-deoxyanthocyanidin synthesis. No SbF3'H3 expression was detected in all tissues examined. The sorghum mesocotyls represent a good system for investigation of differential regulation of F3'H genes/alleles responding to different external stimuli.
Shih
Chun-Hat
CH
Department of Botany, The University of Hong Kong, Pokfulam Road, Hong Kong, PR China.
Chu
Ivan K
IK
Yip
Wing Kin
WK
Lo
Clive
C
D000595:Amino Acid Sequence; D000872:Anthocyanins / Q000096:biosynthesis / Q000737:chemistry; D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis / Q000235:genetics*; D018076:DNA, Complementary / Q000032:analysis; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D006899:Mixed Function Oxygenases / Q000096:biosynthesis / Q000235:genetics*; D008969:Molecular Sequence Data; D015394:Molecular Structure; D012717:Sesquiterpenes; D045868:Sorghum / Q000235:genetics*; D013729:Terpenes / Q000737:chemistry / Q000378:metabolism; D000094162:Phytoalexins
D000872:Anthocyanins; D018076:DNA, Complementary; D012717:Sesquiterpenes; D013729:Terpenes; D003577:Cytochrome P-450 Enzyme System; D006899:Mixed Function Oxygenases; C038888:flavonoid 3'-hydroxylase; D000094162:Phytoalexins