hydroxycinnamoyl-coA quinate hydroxycinnamoyl transferase (HQT) is RESPONSIBLE FOR CHLOROGENIC ACID SYNTHESIS IN PROCESSING POTATO TUBERS

VALIÑAS, M; LANTERI ML; DE LASA C; CALDIZ DO; TEN HAVE A; ANDREU AB

Mar del Plata

Congreso; 8 Encuentro Latinoamerico y del Caribe de Biotecnología Agropecuaria; 2013

Redbio

P { margin-bottom: 0.08in; } Chlorogenic acid (CGA) is a major phenolic component in potato. The biosynthesis of CGA involves the action of the enzymes PAL, C4H, and 4CL, followed by either the consecutive action of HQT and C3?H, or that of HCT, C3?H and HQT. In tomato, it was demonstrated that HQT is required for CGA accumulation, while HCT could be involved in CGA remobilization to lignin synthesis. In order to understand the molecular mechanisms that determine the levels of CGA, we studied: i) the expression of c4h1, c4h2, hct and hqt genes by RT-qPCR; and ii) the levels of CGA by DAD-HPLC, in skin and flesh of potato tubers from four processing varieties. Results show that CGA and transcript levels were higher in skin than in flesh. We found similar expression patterns between c4h1, c4h2 and hqt in flesh, and between c4h1 and hqt in skin; suggesting coordinate expression. In general, hqt expression reflects CGA levels, supporting the idea that this enzyme is responsible for CGA synthesis in Solanaceae. Altogether, results support the hypothesis that regulation of transcript levels plays an essential role in potato phenolic acids metabolism. Overexpression of hqt might be directed to obtain tubers with increased CGA levels.