Breath of the chill: Transcriptomic exploration of respiration and energy metabolism in sweet potato roots during cold storage

Abstract

Chilling injury (CI) significantly affects the postharvest storage of sweet potato (Ipomoea batatas Lam.), leading to quality deterioration and substantial economic losses. This study aimed to elucidate the molecular basis of CI with a focus on respiration and energy metabolism under cold storage. Physiological and enzymatic analyses revealed disruptions in energy homeostasis and metabolic adjustments, including altered activities of respiratory enzymes and increased reliance on alternative respiration pathway. RNA-seq analysis identified differentially expressed genes (DEGs) involved in key metabolic pathways, including mitochondrial respiration, photosynthesis suppression, and proteasome-mediated protein turnover. Weighted gene co-expression network analysis (WGCNA) and gene set enrichment analysis (GSEA) highlighted transcriptional networks and hub genes, including aquaporin PIP2–7, anther specific proteins, VQ protein, and a NF-YB transcription factor, associated with CI progression. These data provide promising targets for developing molecular strategies to improve cold tolerance, thereby extending the shelf life of sweet potatoes and minimizing postharvest losses.