Integrated transcriptomic and metabolomic analysis reveals the regulatory networks in response to heat stress in Pleurotus pulmonarius

An integrated transcriptomic and metabolomic analysis was conducted to elucidate the molecular mechanisms underlying heat stress response in Pleurotus pulmonarius, a commercially important edible mushroom sensitive to elevated temperatures. Through comparative RNA-seq and UPLC-MS based metabolomics, we identified 4,388 differentially expressed genes (DEGs) and 1,282 differentially accumulated metabolites (DAMs) in mycelia exposed to 42 °C for 6 h compared with control conditions. Integrated pathway analysis revealed that pyrimidine metabolism, tryptophan metabolism, and cysteine/methionine metabolism were coordinately reprogrammed at both transcriptional and metabolic levels, forming a synergistic regulatory network. These pathways collectively provide essential precursors for nucleic acid synthesis, modulate auxin (IAA)-mediated stress signaling, and sustain antioxidant capacity, respectively. Our findings establish a systems-level framework for understanding heat adaptation in P. pulmonarius and highlight key metabolic nodes that may serve as targets for molecular breeding of thermotolerant cultivars.