MeJA-Induced Bifunctional Transcription Factor PuMYC2 Regulates Reactive Oxygen Species Homeostasis and Aroma Quality in Cold-Stored Nanguo Pear Fruit

During the postharvest period of fruits, the abnormal accumulation of reactive oxygen species (ROS) is closely associated with the deterioration of fruit quality, which severely impairs the market value and shelf life of fruits. Methyl jasmonate (MeJA) can alleviate postharvest fruit quality deterioration caused by cold storage. Here, we identified PuMYC2 as a positive regulator of ROS scavenging and aroma metabolism in cold-stored Nanguo pear. Overexpression of PuMYC2 upregulated the antioxidant gene PuPOD12 and the aroma synthesis gene PuLOX3–1, resulting in reduced ROS levels and elevated aroma compound contents under cold stress. Yeast one-hybrid (Y1H), electrophoretic mobility shift assay, and β-glucuronidase (GUS) assays confirmed that PuMYC2 directly binds to the promoters of PuPOD12 and PuLOX3–1 to activate their transcription. These findings provide novel insights for optimizing cold storage preservation strategies or advancing molecular mechanisms of fruit quality regulation.