Chlorogenic acid biosynthesis appears linked with suberin production in potato tuber (Solanum tuberosum)

VALIÑAS M; LANTERI M.L.; TEN HAVE A.; ANDREU A. B.

JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY

AMER CHEMICAL SOC

Lugar: Washington; Año: 2015 vol. 63 p. 4902 - 4913

0021-8561

Potato (Solanum tuberosum L.) is a good source of dietary antioxidants. Chlorogenic acid (CGA) and caffeic acid (CA) are the most abundant phenolic acid antioxidants in potato and formed by the phenylpropanoid pathway. A number of CGA biosynthetic routes that involve hydroxycinnamoyl-CoA quinate hydroxycinnamoyl transferase (HQT) and/or hydroxycinnamoyl-CoA shikimate/quinate hydroxycinnamoyl transferase (HCT) have been proposed but little is known in potato. CA production requires a caffeoyl shikimate esterase (CSE) and serves as substrate of lignin precursor ferulic acid, via the action of caffeic/5-hydroxyferulic acid O-methyltransferase (COMT I). CGA is precursor of caffeoyl-CoA and, via caffeoyl-CoA O-methyltransferase (CCoAOMT), of feruloyl-CoA. Feruloyl-CoA is required for lignin and suberin biosynthesis, crucial for tuber development. Here, metabolite and transcript levels of mentioned and related enzymes, such as cinnamate 4-hydroxylase (C4H), were determined in flesh and skin of fresh and stored tubers. Metabolite and transcript levels were higher in skin than in flesh, irrespective of storage. CGA and CA production appear to occur via p-coumaroyl-CoA, using HQT and CSE, respectively. HCT is likely involved in CGA remobilization towards suberin. The strong correlation between CGA and CA, the correspondence with C4H, HQT, CCoAOMT2 and CSE, and the negative correlation of HCT and COMT I in potato tubers, suggest a major flux towards suberin.