Comparative transcriptome analysis reveals the role of sugar signaling in response to high temperature stress in Armillaria gallica.

BACKGROUND: Armillaria gallica establish a unique symbiotic relationship with Gastrodia elata, which is a valuable Chinese herbal plant that relies on this symbiosis. High temperature (HT) seriously affected the growth of both A. gallica and G. elata. However, the molecular mechanisms and gene networks involved in the response of A. gallica to HT are not well understood. RESULTS: In this study, transcriptomic analyses at multiple time point were conducted using rhizomorph from two A. gallica strains, GZ1 (tolerance to HT) and SX8 (sensitive to HT) under HT and normal temperature (NT) conditions. We identified 2,056 differentially expressed genes, primarily associated with carbohydrate metabolism and protein processing in endoplasmic reticulum (ER). Heat shock proteins (HSP20 and HSP90) were up-regulated in both GZ1 and SX8 under HT, indicating a conserved HT induced response in A. gallica. Additionally, genes related to glycolysis were up-regulated in GZ1 following HT treatment, while genes involved in the conversion of sugar to amino acids were down-regulated in GZ1 under HT treatment. GZ1 also showed an increased accumulation of soluble sugar and polysaccharide under HT, which were significantly correlated with pyruvate kinase and aldo/keto reductase genes. Furthermore, a sucrose concentration of 30 g/L enhanced HT resistance in A. gallica. CONCLUSIONS: These results reveal that sugar signaling, particularly in carbohydrate metabolism, plays a critical role in the rhizomorph response to HT stress. Both conserved and species-specific transcriptome changes may contribute to the dynamic regulation of rhizomorph development during adaptation to HT stress in A. gallica. CLINICAL TRIAL NUMBER: Not applicable.