Guanosine 3′,5′-cyclic monophosphate mediates gibberellic acid-induced chilling tolerance and defense response in postharvest peach fruit

Abstract

The mediation of stimulation of chilling tolerance and defense response by guanosine 3′,5′-cyclic monophosphate (cGMP) in response to gibberellic acid (GA3) treatment in peach fruit was explored. The fruit were treated with exogenous GA3 and LY83583 (cGMP inhibitor). It turned out that exogenous GA3 treatment mitigated chilling injury (CI) in postharvest peach fruit. Further, GA3 treatment enhanced guanylyl cyclase (GC) activity, and thereby induced cGMP accumulation. GA3 also up regulated the gene expression of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), glutathione reductase (GR) and glutathione S-transferase (GST). In addition, GA3 treatment enhanced the gene expression of methionine sulfoxide reductase (MSR), and inhibited the gene expression of lipoxygenase (LOX) and phospholipase D (PLD). These above exogenous GA3-stimulated effects were weakened by the addition of LY83583. Overall, cGMP mediated GA3-induced chilling tolerance and defense response in postharvest peach fruit.