A New Regulatory Network Controls Chilling Injury in Peach Fruit by γ-Aminobutyric Acid.

The control of chilling injury in peach fruit by a new regulator network, that exogenous γ-aminobutyric acid (GABA) regulates the metabolisms of polyamines (PAs), the GABA shunt, and proline, is still unclear. This study found that GABA induced an increase in the expression of and and a decrease in the expression of expression, resulting in the accumulation of PAs. There was also an increase in the expression of , which improved GABA content, and an increase in the expression of and , which improved proline content. The correlation analysis showed that an increase in / expression was closely associated with the accumulation of putrescine and that the synergistic increase in the expression of and // was closely related to the accumulation of spermine, proline, and GABA induced by GABA. Importantly, arginine and played a key role in putrescine accumulation, whereas ornithine and / played a crucial role in the synergistic accumulation of spermine, proline, and GABA induced by GABA. This study provides new information on GABA-induced cold tolerance in peach fruit.