The role of gibberellins in the mitigation of chilling injury in cherry tomato (Solanum lycopersicum L.) fruit

Tomato fruit is cold-sensitive and susceptible to chilling injury during cold storage. Bioactive gibberellins (GAs), which play an important role in regulating various physiological processes, have been reported to be involved in stress responses of plant. In this study, we investigated the effect of GA on chilling injury of harvested cherry tomato fruit. We found that low temperature significantly inhibited increase of endogenous levels of gibberellic acid (GA(3)) in fruit. This effect was associated with lower expression of key GA metabolic genes, GA3ox1,GA20ox1 and GA2ox1. GA(3) treatment reduced the chilling injury index, whereas treatment with paclobutrazol (PAC), a GA biosynthesis inhibitor, exacerbated chilling injury. Compared with the control, GA(3) treatment decreased electrolyte leakage and malondialdehyde content, increased proline content, and improved antioxidant enzyme activities. Treatment with PAC caused the opposite effects. These results suggest that endogenous GA levels were positively associated with lipid peroxidation and oxidative stress in chilled fruit. GA appears to play an important role in cold response regulation in fruit. (C) 2014 Elsevier B.V. All rights reserved.