Peach (Prunus persica) is highly sensitive to low-temperature storage, a necessary practice for extending market shelf life. Prolonged cold exposure induces chilling injury (CI), characterized by internal browning, disrupted softening, oxidative stress, and reduced consumer acceptance. Although methyl jasmonate (MeJA) has been widely reported to alleviate CI in various fruits, the molecular mechanisms connecting jasmonate signaling to hormone crosstalk and antioxidant pathways in peach remain poorly understood. MYC2 is recognized as a master regulator of jasmonate signaling in many species, yet its regulatory circuitry in peach fruit under cold stress has not been clarified. Based on these challenges, in-depth investigation into the transcriptional networks underlying MeJA-mediated cold tolerance is urgently needed.

Researchers from the National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, report (DOI: 10.1093/hr/uhaf295) a mechanistic advance in Horticulture Research (2026). The team demonstrates that exogenous MeJA treatment alleviates CI in peach fruit by activating a jasmonate-responsive transcriptional module centered on PpMYC2.1. Through integrated RNA-seq, DAP-seq, and functional assays, they uncover how this regulator coordinates ethylene biosynthesis, phenylpropanoid metabolism, and cell wall modification during cold storage.

Physiological analyses showed that MeJA-treated peaches exhibited significantly reduced internal browning and lower levels of reactive oxygen species, accompanied by enhanced ethylene production and increased accumulation of polyphenols and flavonoids. Transcriptomic profiling identified thousands of differentially expressed genes, highlighting PpMYC2.1 as a key cold-responsive transcription factor. DAP-seq revealed nearly 10,000 high-confidence binding peaks for PpMYC2.1, primarily enriched in promoter regions containing G-box motifs. Integration of DAP-seq and RNA-seq datasets identified 1,920 direct target genes involved in ethylene signaling, phenylpropanoid biosynthesis, and cell wall remodeling. Unlike apple MYC2, which directly regulates ethylene biosynthetic genes, PpMYC2.1 indirectly modulates ethylene production by activating upstream regulators such as PpIAA1, PpERF61, and PpHB.G7. It also directly promotes transcription of cell wall-related genes (PpPG2, PpPL1, PpXTH2) to restore normal softening under cold conditions. Furthermore, it enhances antioxidant capacity by activating phenylpropanoid pathway genes including PpPAL1, Pp4CL, PpCHI3, and PpCHS. Mechanistically, MeJA downregulates PpJAZ2 and PpJAZ4, which normally repress PpMYC2.1. Their suppression releases PpMYC2.1 activity, reprogramming stress-responsive gene networks. Stable overexpression of PpMYC2.1 in tomato further confirmed enhanced chilling tolerance, reduced oxidative damage, and improved fruit quality.

“This work reveals a previously uncharacterized jasmonate-responsive module that coordinates multiple physiological pathways under cold stress,” said the corresponding author. “By integrating hormone signaling, antioxidant metabolism, and cell wall remodeling, PpMYC2.1 acts as a transcriptional hub that maintains fruit quality during storage. Understanding this regulatory switch provides new molecular targets for breeding and postharvest management strategies in climacteric fruits.”

The identification of the PpJAZ2/4–PpMYC2.1 regulatory module offers practical implications for cold chain management and fruit breeding. By manipulating jasmonate signaling or modulating MYC2 activity, it may be possible to develop cultivars with enhanced chilling tolerance while preserving flavor and texture. The findings also highlight the broader significance of hormone crosstalk in stress adaptation, suggesting that similar regulatory frameworks may operate in other climacteric fruits. Beyond peach, this study provides a conceptual model for improving postharvest preservation through targeted transcriptional engineering, reducing economic losses and enhancing food quality in global fruit supply chains.

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