The Fungi-specific histone Acetyltransferase Rtt109 mediates morphogenesis, Aflatoxin synthesis and pathogenicity in Aspergillus flavus by acetylating H3K9

Aspergillus flavus is a common saprophytic filamentous fungus that produces the highly toxic natural compound aflatoxin during its growth process. Synthesis of the aflatoxins, which can contaminate food crops causing huge losses to the agricultural economy, is often regulated by epigenetic modification, such as the histone acetyltransferase. In this study, we used Aspergillus flavus as an experimental model to construct the acetyltransferase gene rtt109 knockout strain (ortt109) and its complementary strain (ortt109 center dot com) by homologous recombination. The growth of ortt109 was significantly suppressed compared to the wild type (WT) strain and the ortt109 center dot com strain. The sclerotium of ortt109 grew smaller, and the amount of sclerotia generated by ortt109 was significantly reduced. The number of conidiums of ortt109 was significantly reduced, especially on the yeast extract sucrose (YES) solid medium. The amount of aflatoxins synthesized by ortt109 in the PDB liquid medium was significantly decreased We also found that the ortt109 strain was extremely sensitive to DNA damage stress. Through the maize seed infection experiment, we found that the growth of ortt109 on the surface of affected corn was largely reduced, and the amount of aerial mycelium decreased significantly, which was consistent with the results on the artificial medium. We further found that H3K9 was the acetylated target of Rtt109 in A. flavus. In conclusion, Rtt109 participated in the growth, conidium formation, sclerotia generation, aflatoxin synthesis, environmental stress response, regulation of infection of A. flavus. The results from this study of rtt109 showed data for acetylation in the regulation of life processes and provided a new thought regarding the prevention and control of A. flavus hazards.

Automated summary

Aspergillus flavus is a common filamentous fungus that produces the highly toxic compound aflatoxin. The study used Aspergillus flavus as a model organism to investigate the role of acetyltransferase gene rtt109, finding that it plays a crucial role in growth, conidium formation, sclerotia generation, aflatoxin synthesis, environmental stress response, and infection regulation in A. flavus.