Expanding the understanding of Volvariella volvacea autolysis at 4°C with transcriptomics and metabolomics

Abstract

Volvariella volvacea is a type of high-temperature edible fungus that is prone to low-temperature autolysis, which makes postharvest storage and long-distance transportation difficult. In this study, transcriptomics integrated with metabolomics analysis provided the profiling of genes and metabolites in V. volvacea fruiting bodies stored at 4 °C. According to the transcriptomics and metabolomics analysis, 1613 and 1846 differentially expressed genes, 126 and 136 differential metabolites were identified at 12 h and 24 h compared to control (0 h), respectively. 6 common metabolic pathways were found by integrated analysis, of which starch and sucrose metabolism and pyruvate metabolism were further analyzed. The results exhibited that low-temperature autolysis was the consequence of the intracellular and extracellular interactions. Expression changes of genes (CEL2, CEL3, CEL6B and GH5–1) involved in cellulose metabolism led to the degradation of cellular structure. The rapid reduction of soluble sugar resulted in a decrease in the cytoplasmic concentration and an increase in osmotic potential, thereby liquefying the surface of fruiting bodies. The differential metabolites and genes of malate metabolism participated in the electron supply of the electron transport chain, but long-term low temperature made the intracellular energy supply insufficient, causing cold damage. This study provides a theoretical basis for further understanding in the mechanisms of low-temperature autolysis of V. volvacea.