Fusarium graminearum is an important fungal pathogen that causes Fusarium head blight in wheat and stalk rot in maize, threatening crop yield and grain quality. Current disease control relies mainly on fungicides and resistant varieties, making the identification of new molecular targets important. Chromatin regulators participate in the regulation of fungal gene expression, but their roles in the pathogenesis of F. graminearum remain to be further elucidated.
The team of Professors Dong Jingao and Xing Jihong at Hebei Agricultural University functionally characterized the histone variant H2A.Z in F. graminearum . Through bioinformatic mining, multiple sequence alignment and phylogenetic analysis, the study identified FgHTZ1 as the gene encoding H2A.Z. Using homologous recombination combined with PEG-mediated protoplast transformation, the researchers constructed FgHTZ1 deletion mutants and compared them with the wild-type strain in terms of morphology, pathogenicity and abiotic stress responses.
The results showed that deletion of FgHTZ1 caused significantly delayed colony growth in some mutants and generally affected hyphal polar growth and conidial development: hyphal septum spacing and hyphal diameter were reduced, conidial length was shortened, and conidiation decreased. More importantly, the deletion mutants showed significantly attenuated pathogenicity, indicating that H2A.Z is required for full pathogenicity in F. graminearum . The mutants also exhibited a complex stress-response phenotype: increased tolerance to the cell wall-perturbing agent Congo red, but hypersensitivity to osmotic stress caused by NaCl and sorbitol and to oxidative stress induced by H₂O₂. These results indicate that H2A.Z is involved in osmotic and oxidative stress adaptation and plays an important role in cell wall integrity.
The research team noted that H2A.Z acts as a positive regulator in the growth, development and pathogenesis of F. graminearum . Further studies are still needed to identify H2A.Z-bound genes and downstream pathways and to evaluate whether interfering with H2A.Z-mediated regulation can reduce infection under field conditions, thereby determining the feasibility of this chromatin pathway as a target for crop fungal disease control.
The study was published online in Acta Microbiologica Sinica on June 3, 2026. It provides a theoretical basis for understanding how histone variants participate in the pathogenesis of plant pathogenic fungi and may offer new insights for the sustainable management of Fusarium diseases.
ACTA MICROBIOLOGICA SINICA
Roles of histone variant H2A.Z in the growth, development, and pathogenic mechanism of Fusarium graminearum
4-Oct-2026