A global metabolomic and transcriptomic insight into the mechanism of salicylic acid enhancing resistance of Pleurotus ostreatus to heat stress

Heat stress (HS) is one of the most important environmental factors, which are a serious threat to agriculture production. Pleurotus ostreatus is cultivated widly in the word, and its growth was seriously threatened by HS. The phytohormone salicylic acid (SA) controls biotic and abiotic plant stress responses, but little is known about the role of SA in microorganisms. Here, we performed a comprehensive analysis to investigate the influence of SA in P. ostreatus under HS. Results showed that the hyphal recovery growth rate and the antioxidant capacity of P. ostreatus increased with exogenous SA application (0.01 mM and 0.05 mM) after HS treatment. Metabolomic and transcriptomic analysis showed that SA application (0.05 mM) weakened central carbon metabolism to allow cells to survive in an economical way under HS. In addition, SA shifted glycolysis to one carbon metabolism to produce ROS scavenger (GSH and NADPH), and reduced ROS production by reshaping mitochondrial metabolism. SA also maintained nucleotide homeostasis, led to membrane lipid remodeling, activated the MAPK pathway and synthesis of cell wall components. This study provide reference for further study of SA in microorganisms.