Overexpression of Sly-miR167a delayed postharvest chilling injury of tomato fruit under low temperature storage

Abstract

Chilling injury (CI) of tomato fruit leads to the deterioration of fruit quality, thereby shortening the shelf life of tomato fruit. The present experiment investigates the effect of Sly-miR167a on postharvest cold tolerance of tomato fruit. Results demonstrated that overexpression of Sly-miR167a in tomato fruit effectively reduced electrolyte leakage (EL), hydrogen peroxide (H2O2) content, malondialdehyde (MDA) content and CI index during low temperature storage. Compared with wild-type (WT) and the silencing miR167a by short tandem target mimic (miR167a-STTM) fruit, overexpression of Sly-miR167a (miR167a-OE) fruit accumulated more ascorbic acid (AsA), proline, lycopene, and phenolics, and also maintained higher activities of antioxidant enzymes. At low temperatures, miR167a-OE fruit sustained better quality, and had lower expression levels of ARF6a, higher levels of ethylene production and higher expression levels of CBF1. Overexpression of Sly-miR167a delayed the appearance of CI symptoms, improving the chilling tolerance of postharvest tomato fruit.