Involvement of abscisic acid in postharvest water-deficit stress associated with the accumulation of anthocyanins in strawberry fruit

Fruits are prone to suffer water-deficit stress and accelerated senescence after harvest. To understand the effect of postharvest water-deficit on the senescence progress of strawberry fruit, fruit peduncles were dipped into water or abscisic acid solution and stored at 20 degrees C with 50% relative humidity in the dark. The results showed that detached fruit without water supply through the peduncles suffered serious waterdeficit stress with great weight loss and low moisture content. However, fruit absorbing water through their peduncles successfully avoided the water-deficit stress with a slight change of weight loss and moisture content. Water-deficit significantly promoted anthocyanin levels with increased PAL C4H and DFR activities. The expressions of transcriptional factors that regulate a nthocyanin biosynthesis (FaMYB1, FabHLH3 and FaITG1) were also up-regulated under water-deficit stress. Meanwhile, stress elevated the abscisic acid level as well as FaNCED1 and FaASR expression in strawberry fruit. Furthermore, exogenous ABA application exhibited the similar features with water-deficit stress. These results suggested that postharvest water-deficit would accelerate anthocyanin accumulation in strawberry fruit and that abscisic acid may play a role in the response to water-deficit stress. (C) 2015 Published by Elsevier B.V.