CEFOBI   05405
CENTRO DE ESTUDIOS FOTOSINTETICOS Y BIOQUIMICOS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Characterization and Regulation of the First Flavonol Synthase identified in Maize
Autor/es:
SEBASTIÁN P. RIUS; MA LORENA FALCONE FERREYRA; JULIA EMILIANI; LUCILLE POURCEL; ANTJE FELLER; KENGO MOROHASHI; PAULA CASATI; ERICH GROTEWOLD
Lugar:
Tucumán
Reunión:
Congreso; XLV Reunión Annual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB); 2009
Resumen:
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Flavonoids, a broad collection of specialized
compounds containing the C6-C3-C6 carbon framework, are widely distributed
throughout the plant kingdom. These compounds have diverse functions in plants,
and they are benefitial for humans health. Flavonols are synthesized from the
dihydroflavonols dihydrokaempferol (DHK), dihydroquercetin (DHQ) or dihydromyricetin
by the action of flavonol synthase (FLS) enzymes. We identified and characterize
a maize FLS (ZmFLS1). ZmFLS1 can use DHK and DHQ as substrates
but show preference for DHK: it has a higher catalytic efficiency and a lower Km value than for DHQ. fls-1Arabidopsis mutant plants
complemented with ZmFLS1 partially restored
the anthocyanin levels and production of kaempferol and quercetin. By combining
transient expression assays in maize Black Mexican Sweet (BMS) cells and
chromatin immunoprecipitation (ChIP) experiments, we demonstrate that Zmfls1 is a direct target of the P1 and
C1/R regulators of flavonoid biosynthesis. Highlighting a role of flavonols in
UV-B protection, we show that the expression of ZmFLS1 is significantly enhanced by UV-B in maize leaves. The
results presented here demonstrate the activity, regulation and role of the
first FLS characterized from maize in the flavonoid pathway.