Chlorogenic Acid Biosynthesis Appears Linked with Suberin Production in Potato Tuber (Solanum tuberosum)

Abstract

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 are 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 about their path in potato. CA production requires a caffeoyl shikimate esterase (CSE), and CA serves as a 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 the mentioned and related enzymes, such as cinnamate 4-hydroxylase (C4H), were determined in the 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 toward 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 toward suberin.

MdMyb93 is a regulator of suberin deposition in russeted apple fruit skins

“…In potato, it has been suggested that chlorogenic acids, as well as coumaroyl-quinic acids, accumulate in the tuber as phenolic compound storage pools, which can be re-mobilized according to the plant's needs (e.g. detoxification of reactive oxygen species in the case of oxidative stress, or lignin/suberin production) (Valinas et al, 2015). It is therefore likely that the hydroxycinnamic ester and flavonoid molecules observed in the present experiment serve as precursors of feruloyl-CoA through the action of hydroxycinnamoyl transferase (HCT), caffeoyl-CoA O-methyltransferase (CCoAOMT), and caffeic/5hydroxyferulic acid O-methyltransferase (COMT1), directing the flux towards suberin production.…”

Health‐beneficial properties of potato and compounds of interest

“…The main potato antioxidants are polyphenols (1.226–4.405 mg kg −1 ), ascorbic acid (170–990 mg kg −1 ), carotenoids (as high as 4 mg kg −1 ), tocopherols (0.5–2.8 mg kg −1 ), selenium (0.01 mg kg −1 ) and α ‐lipoic acid . Chlorogenic acid is the primary phenolic compound (being more than 90% of phenolics) found in potatoes . In a US study, the total phenolic content of peeled potato was 28 mg per 100 g FW and it was ranked 20th out of 23 commonly consumed vegetables and was ranked ninth in terms of antioxidant activity .…”

“…1 Chlorogenic acid is the primary phenolic compound (being more than 90% of phenolics) found in potatoes. 10,22,77 In a US study, the total phenolic content of peeled potato was 28 mg per 100 g FW and it was ranked 20th out of 23 commonly consumed vegetables and was ranked ninth in terms of antioxidant activity. 78 Flavonoid and flavone extracts from potatoes show high scavenging activities toward oxygen radicals.…”

Suberin and hemicellulose in sugarcane cell wall architecture and crop digestibility: A biotechnological perspective

“…So, it is important to understand the factors and biochemical pathways that favor specific phenylpropanoids pools and classes of lipids at specific tissues in order to design genetic and metabolomic engineering strategies in order to improve suberin and associated waxes deposition on bioenergy plants like sugarcane. Recently, several key enzymes have been determined to be responsible for the remobilization of storage phenolic compounds such as chlorogenic acids and coumaroyl‐quinic acids toward secondary metabolism, including, to this matter, lignin and suberin production (Valiñas, Lanteri, Have, & Ten Andreu, ). In potato, hydroxycinnamoyl transferase (HCT), caffeoyl‐CoA O ‐methyltransferase (CCoAOMT), and COMT1 use coumaroyl‐quinic acids and chlorogenic acid as precursors to the production of feruloyl‐CoA, directing this metabolomic pathway to suberin production (Valiñas et al., ).…”

“…Recently, several key enzymes have been determined to be responsible for the remobilization of storage phenolic compounds such as chlorogenic acids and coumaroyl‐quinic acids toward secondary metabolism, including, to this matter, lignin and suberin production (Valiñas, Lanteri, Have, & Ten Andreu, ). In potato, hydroxycinnamoyl transferase (HCT), caffeoyl‐CoA O ‐methyltransferase (CCoAOMT), and COMT1 use coumaroyl‐quinic acids and chlorogenic acid as precursors to the production of feruloyl‐CoA, directing this metabolomic pathway to suberin production (Valiñas et al., ). Curiously, in sugarcane internodes, the main phenolic compounds are chlorogenic and coumaric acids with significative smaller contents of ferulic and caffeic acids (Bottcher et al., ; Costa et al., ).…”