Sodium hydrosulfide application induces chilling tolerance in banana fruits by enhancing antioxidant gene expression through the upregulation of the ethylene response factors MaERF53L/121L

Abstract

Sodium hydrosulfide (NaHS), a hydrogen sulfide (H₂S) donor, effectively mitigates chilling injury (CI) in bananas; however, the underlying molecular mechanisms remain unclear. This study demonstrated that NaHS alleviates CI symptoms by activating antioxidant defense systems that reduce oxidative stress induced by CI. Transcriptomic analysis revealed 1003 differentially expressed genes in three sample groups, with enrichment in pathways related to cellular processes, metabolic activity, and secondary metabolite biosynthesis. NaHS treatment significantly upregulated seven ethylene response factors, among which MaERF53L and MaERF121L functioned as transcriptional activators. Further investigation revealed that MaERF53L and MaERF121L directly bind to the promoters of MaPOD3 and MaGSTU18, enhancing their expression as well as the antioxidant enzyme activity. These findings indicate that the activation of antioxidant genes by MaERF53L and MaERF121L is central to NaHS-induced CI mitigation in bananas, providing novel insights into the role of H₂S in reducing CI across horticultural crops.