Long-term exposure treatments revert the initial SA-induced alterations of phenolic metabolism in grapevine cell cultures

Abstract

Vitis vinifera L. cv. Monastrell calli were used to evaluate the effects of long-term exposure to different salicylic acid (SA) concentrations (0.00, 0.01, 0.10 and 1.00 mM) on cell growth and phenolic metabolism. The impaired cell growth caused by high SA concentrations after the first sub-culture of cells was reverted to normal growth even in the presence of 1 mM SA after a few cycles of repeated culture in the same conditions. The initial alterations in the levels of total soluble phenolics, and in the peroxidase (PRX) activity, especially when resveratrol was used as substrate, were also counteracted upon long-term exposure to the phytohormone. Moreover, the recovering of PRX enzymatic activity paralleled the restoration of the PRX isoenzyme pattern. Since phenolic compounds and PRXs can be considered as markers of stress the restoration of their constitutive levels could be considered as indicators of cessation of stress allowing cells to reassume their normal growth and metabolic functions, even in the stressing initial conditions.