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

• Postharvest strawberry fruit suffer serious water-deficit stress.
• Water-deficit accelerates anthocyanin accumulation in strawberry fruit.
• Water-deficit can promote ABA biosynthesis and signaling transduction.
• ABA may be a regulator in the response of strawberries to water-deficit stress.

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 °C with 50% relative humidity in the dark. The results showed that detached fruit without water supply through the peduncles suffered serious water-deficit 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 anthocyanin biosynthesis (FaMYB1, FabHLH3 and FaTTG1) 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.