Impact of light irradiance on the biosynthesis of ABA-elicited phenolic compounds in suspension-cultured Vitis vinifera L. cells

Phenolic compounds found in the berries of the grapevine Vitis vinifera L. are reported to reduce the incidence of some non-transmissible chronic pathologies such as cardiovascular diseases, cancer, obesity and diabetes. Elicitation of plant cell suspension cultures offers a way to experimentally determine how manipulating metabolic pathways can result in biosynthesis of higher levels of desired secondary metabolites. The goal of this work was, using cell suspension cultures of callus tissues obtained from berry slices of V. vinifera cv. Shahani grown on an optimized medium, to investigate the effects of elicitation on the synthesis of stilbene compounds including trans-resveratrol and its glucoside trans-piceid, and anthocyanin pigments. The effects of different concentrations of the phytohormone abscisic acid (ABA; 0, 50, 100 and 200 µM) applied to cell suspension cultures grown under either high-level light irradiation (135.1 μmol. s−1 m−2) or zero light conditions, were tested. The results showed that compared with dark conditions, cells treated with continuous light irradiation were capable of accumulating significantly higher levels of anthocyanin in all of the ABA concentrations. Cell cultures subjected to high-level light irradiation did not show statistically higher piceid amounts than cells grown in dark condition except for 200 µM ABA. A similar trend was found for resveratrol content of the cells exposed to the darkness. When cultures were grown in the presence of 200 µM ABA under dark conditions, the accumulation of trans-resveratrol was seen at 4.12 and 3.02-fold higher levels than in dark and light-grown control cultures respectively. Surprisingly, following light irradiation of 135.1 μmol. s−1 m−2 with 200 µM ABA, the cells accumulated the highest level of trans-piceid. This represented a remarkable increase of 19.97 and 12.71-fold in comparison with dark and light-grown control cultures respectively. In addition, the combined elicitation of light irradiation and 50 µM abscisic acid was found to be the most effective treatment for the production of anthocyanin. This value was 64.00 and 5.55-fold higher than those of the controls, respectively. These data suggest that the transduction pathway of abscisic acid is part of a complex signaling network that includes the visible light signaling pathway. Similarly, the results of the current study suggest that combinations of dark/light together with abscisic acid can be used as an efficient method for the future scale-up of V. vinifera cell cultures for the production of high value phenolic compounds in a bioreactor system. The influence of elicitation culture media with the phytohormone abscisic acid in combination or not with high-level light condition on stimulating valuable phenolic compounds production in cell suspension cultures of Vitis vinifera L. was proved.