The lysine deacetylases AsKDAC1 and AsKDAC6 regulate growth, stress response, and virulence in Apiospora sphaerosperma

BACKGROUND: Shoot dieback caused by Apiospora sphaerosperma severely compromises the ecological and economic value of Bambusa pervariabilis × grandis. Reversible lysine acetylation has emerged as an important regulator of fungal pathogenesis, yet the functions of lysine deacetylases (KDACs) in A. sphaerosperma remain poorly understood. This study aimed to systematically characterize two core deacetylase genes, AsKDAC1 and AsKDAC6, and elucidate their regulatory networks. RESULTS: Both AsKDAC1 and AsKDAC6 contributed to vegetative growth, asexual reproduction, stress responses, DNA damage repair, and virulence. Notably, deleting AsKDAC1 and AsKDAC6 reduced conidiation by 12.10% and 45.97%, respectively. At 30 days post-inoculation, the wild-type disease index reached 85.83%, whereas ΔAsKDAC1 and ΔAsKDAC6 mutants exhibited indices of 50.00% and 46.25%, respectively, with virulence attenuation becoming evident at 20 and 15 days. Comparative transcriptomics of ΔAsKDAC6 identified 3916 up- and 3771 down-regulated genes, while acetylproteomics revealed 1490 unique acetylation sites across 846 proteins, with 501 proteins being differentially acetylated. These alterations were mainly associated with carbon metabolism and protein translation. CONCLUSION: AsKDAC1 and AsKDAC6 fulfill important and distinct roles in fungal development and pathogenicity. By mapping the AsKDAC6-regulated transcriptome and acetylproteome, this study uncovers the molecular basis of these defects, advancing the understanding of post-translational modifications in plant-pathogen interactions. © 2026 Society of Chemical Industry.