Genome-wide identification of histone acetyltransferase genes in Solanum melongena reveals two critical regulators of Botrytis cinerea resistance

Histone acetylation, a crucial post-translational modification catalyzed by histone acetyltransferases (HATs), plays a pivotal role in plant stress responses. While HATs are known to mediate disease resistance, their functional characterization in eggplant remains poorly understood. Here, we demonstrate through Western blotting and ChIP-PCR analyses that Botrytis cinerea infection dynamically modulates global histone acetylation patterns in eggplant leaves. A genome-wide investigation identified 25 SmHAT genes and systematically characterized their conserved domains, motif organization, and evolutionary relationships. Expression profiling revealed distinct spatial-temporal patterns of SmHAT members between resistant and susceptible cultivars during B. cinerea infection, suggesting functional diversification in disease resistance pathways. Functional validation through transient overexpression and virus-induced gene silencing demonstrated that SmHAT7 acts as a positive regulator, while SmHAT17 functions as a negative regulator of resistance of eggplant to B. cinerea. Collectively, our results demonstrate that histone acetylation mediating by HATs plays an important role in B. cinerea resistance in eggplant. This work provides novel insights into epigenetic regulation of disease resistance and proposes potential molecular targets for breeding B. cinerea-resistant cultivars.