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:
<!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";} @page Section1 {size:612.0pt 792.0pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> 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 human’s 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.