Flavonoid biosynthetic genes

PELLETIER, M.K., MURRELL, J., SHIRLEY, B.W., Arabidopsis flavonol synthase and leucoanthocyanidin dioxygenase further evidence for distinct regulation of "early" and "late" flavonoid biosynthetic genes, Plant Physiol., 1997,113, 1437-1445. 

KUBASEK, W.L., SHIRLEY, B.W., MCKILLOP, A., GOODMAN, H.M., BRIGGS, W., AUSUBEL, F.M., Regulation of flavonoid biosynthetic genes in germinating Arabidopsis seedlings, Plant Cell, 1992, 4,1229-1236. 

The 4-coumarate CoA ligase (4CL EC 6.2.1.12) enzyme activates 4-coumaric acid, caffeic acid, ferrulic acid, and (in some cases) sinapic acid by the formation of CoA esters that serve as branch-point metabolites between the phenylpropanoid pathway and the synthesis of secondary metabolites [46, 47]. The reaction has an absolute requirement for Mg " and ATP as cofactors. Multiple isozymes are present in all plants where it has been studied, some of which have variable substrate specificities consistent with a potential role in controlling accumulation of secondary metabolite end-products. Examination of a navel orange EST database (CitEST) for flavonoid biosynthetic genes resulted in the identification of 10 tentative consensus sequences that potentially represent a multi-enzyme family [29]. Eurther biochemical characterization will be necessary to establish whether these genes have 4CL activity and, if so, whether preferential substrate usage is observed. 

Transcription Factors that Regulate Flavonoid Biosynthetic Genes... 

Note The functions of the transcription factors have been confirmed (or indicated) by genetic mutant or plant transgenic studies. They are activators of transcription unless stated otherwise. Some are direct activators of the flavonoid biosynthetic genes, while others may encode factors upstream in a regulatory cascade. 

Genetic Modification of Flavonoid Production Using Inhibition of Flavonoid Biosynthetic Gene Activity by Sense or Antisense RNA... 

Genetic Modification of Flavonoid Production in Stably Transformed Plants or Cell Lines by Introduction of Genes Encoding Transcription Factors that Regulate Flavonoid Biosynthetic Genes (All "Sense Transgenes)... 

Collette, V.E. et al., Temporal and spatial expression of flavonoid biosynthetic genes in flowers of Anthurium andraeanum. Physiol. Plant., 122, 297, 2004. 

Kubasek, W.L. et al.. Regulation of flavonoid biosynthetic genes in germinating Arabidopsis seedlings. Plant Cell, 4, 1229, 1992. 

The identification and isolation of genes involved in flavonoid biosynthesis has benefited from the fact that many of the flavonoids are colored compounds. Mutant phenotypes are therefore often easily identifiable based on variation in color. In Arabidopsis many of the genes involved in flavonoid bioysnthesis have been uncovered based on the change in seed coat (testa) color. Wild-type Arabidopsis seeds have a brown color, and mutations in flavonoid biosynthetic genes result in yellow or pale brown color because the underlying cotyledons are visible. These mutants are referred to as... 

Grotewold, E., Drummond, B. J., Boen, B., and Peterson, T., 1994, The myh -homologous P gene controls phlobaphene pigmentation in maize floral organs by directly activating a flavonoid biosynthetic gene subset, Cell 76 543-553. 

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