[Objective] As a key component of eukaryotic chromatin, histone variant H2A.Z plays an important role in gene expression regulation. This study explored the regulatory effects of H2A.Z on the biological characteristics and pathogenicity of Fusarium graminearum, aiming to decipher its epigenetic regulation mechanism in the pathogenicity of pathogenic fungi. [Methods] The genome of F. graminearum was excavated by bioinformatics methods, and the H2A.Z homologous genes were identified by multiple sequence alignment and phylogenetic analysis. The gene deletion mutants were constructed by homologous recombination combined with PEG-mediated protoplast transformation. The phenotypic differences in morphological development, pathogenicity, and environmental adaptability between the wild type and the mutants were systematically evaluated by morphological observation, pathogenicity determination, and abiotic stress response experiments. [Results] H2A.Z was encoded by FgHTZ1. Phenotypic analysis showed that the deletion of FgHTZ1 resulted in significant retardation of colony growth, abnormal mycelial polar growth and conidial morphogenesis, and significant attenuation in pathogenicity. In addition, the mutants showed significantly altered sensitivity to osmotic stress (NaCl and sorbitol), oxidative stress (H2O2), and cell wall damage (Congo red), exhibiting a complex phenotype of enhanced tolerance to cell wall disruptors but hypersensitivity to osmotic/oxidative stress. [Conclusion] FgHTZ1 is the coding gene of H2A.Z in F. graminearum. As a positive regulator, this gene not only regulates the vegetative growth, morphological development, and pathogenicity of F. graminearum but also participates in mediating osmotic stress and oxidative stress responses, playing a key role in maintaining cell wall integrity. This study provides an important theoretical basis for further understanding the molecular functions of histone variants in the pathogenic mechanisms of plant pathogenic fungi.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |