Transcriptomics and Physiological Analysis Reveal Response Strategies of Sanghuangporus baumii to Aluminum Exposure

Abstract

Sanghuangporus baumii, a medicinal macrofungus, remains unexplored in its response to aluminum stress, despite the widespread environmental relevance of this metal. This study investigated the dose-dependent effects of Al3+ on mycelial growth and metabolic regulation. Exposure to 1 mM Al3+ moderately stimulated growth (1.11-fold of control) and induced mild oxidative stress, which activated an effective antioxidant response—including increased SOD, CAT, and POD activities and elevated reduced glutathione content—thereby maintaining redox balance and increasing soluble sugar content. In contrast, 10 mM Al3+ led to pronounced intracellular Al3+ accumulation, severe growth inhibition, and marked oxidative damage, accompanied by impairment of the antioxidant system, yet a marked increase in total triterpenoid content (1.72-fold). Transcriptomic analysis identified 642 and 3019 differentially expressed genes (DEGs) in the 1 and 10 mM Al3+ treatments, respectively. KEGG enrichment analysis revealed concentration-dependent alterations in pathways related to peroxisome function, glutathione metabolism, starch and sucrose metabolism, and terpenoid backbone biosynthesis. Collectively, these findings suggest that Al3+ modulates S. baumii growth and metabolism in a dose-dependent manner, with redox remodeling as a potential mechanism, offering novel insights into fungal metal adaptation and the targeted modulation of medicinal metabolite production.