Developmental, genetic and environmental factors affect the expression of flavonoid genes, enzymes and metabolites in strawberry fruits
Carbone, F. ; Preuss, A. ; Vos, C.H. de; Amico, E. d'; Perrotta, G. ; Bovy, A.G. ; Martens, S. ; Rosati, C. - \ 2009
Plant, Cell & Environment 32 (2009)8. - ISSN 0140-7791 - p. 1117 - 1131.
fragaria x ananassa - cellular-localization - phenolic-compounds - quality traits - biosynthesis - arabidopsis - pathway - proanthocyanidins - accumulation - dioxygenases
The influence of internal (genetic and developmental) and external (environmental) factors on levels of flavonoid gene transcripts, enzyme activity and metabolites was studied in fruit of six cultivated strawberry (Fragaria × ananassa Duch.) genotypes grown at two Italian locations. Gene expression and enzyme activity showed development- and genotype-associated patterns, revealing gene coordination. Analysis clarified the regulation mechanism of the hydroxylation status of the B-ring of the major flavonoid pools and pointed out examples of genotype-specific post-transcriptional regulation mechanisms and key steps of pathway regulation in strawberry fruits. Metabolite profiles were strongly affected by development and genotype. Flavan-3-ols, their proanthocyanidin (PA) derivatives and anthocyanins were the most abundant metabolites. Flavonol levels and PA-associated traits (epicatechin/catechin ratio and mean degree of polymerization) showed significant environmental effects. Multivariate and correlation analyses determined the relationships among genes, enzymes and metabolites. The combined molecular and biochemical information elucidated more in depth the role of genetic and environmental factors on flavonoid metabolism during strawberry fruit development, highlighting the major impact of developmental processes, and revealing genotype-dependent differences and environmental effects on PA-related traits.
Characterization of major enzymes and genes involved in flavonoid and proanthocyanidin biosynthesis during fruit development in strawberry (Fragaria x ananassa).
Almeida, J.R. ; Amico, E. d'; Preuss, A. ; Carbone, F. ; Vos, C.H. de - \ 2007
Archives of Biochemistry and Biophysics 465 (2007)1. - ISSN 0003-9861 - p. 61 - 71.
dihydroflavonol 4-reductases - leucoanthocyanidin reductase - anthocyanidin reductases - heterologous expression - antioxidant activity - molecular-cloning - quality traits - synthase - identification - leaves
The biosynthesis of flavonoids and proanthocyanidins was studied in cultivated strawberry (Fragaria x ananassa) by combining biochemical and molecular approaches. Chemical analyses showed that ripe strawberries accumulate high amounts of pelargonidin-derived anthocyanins, and a larger pool of 3',4'-hydroxylated proanthocyanidins. Activities and properties of major recombinant enzymes were demonstrated by means of in vitro assays, with special emphasis on specificity for the biologically relevant 4'- and 3',4'-hydroxylated compounds. Only leucoanthocyanidin reductase showed a strict specificity for the 3',4'-hydroxylated leucocyanidin, while other enzymes accepted either hydroxylated substrate with different relative activity rates. The structure of late flavonoid pathway genes, leading to the synthesis of major compounds in ripe fruits, was elucidated. Complex developmental and spatial expression patterns were shown for phenylpropanoid and flavonoid genes in fruits throughout ripening as well as in leaves, petals and roots. Presented results elucidate key steps in the biosynthesis of strawberry flavonoid end products. (c) 2007 Elsevier Inc. All rights reserved.