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 (△rtt109) and its complementary strain (△rtt109·com) by homologous recombination. The growth of △rtt109 was significantly suppressed compared to the wild type (WT) strain and the △rtt109·com strain. The sclerotium of △rtt109 grew smaller, and the amount of sclerotia generated by △rtt109 was significantly reduced. The number of conidiums of △rtt109 was significantly reduced, especially on the yeast extract sucrose (YES) solid medium. The amount of aflatoxins synthesized by △rtt109 in the PDB liquid medium was significantly decreased We also found that the △rtt109 strain was extremely sensitive to DNA damage stress. Through the maize seed infection experiment, we found that the growth of △rtt109 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.

中文翻译：

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具体真菌组蛋白乙酰转移酶介导Rtt109形态发生，黄曲霉毒素合成和致病性在黄曲霉通过乙酰化H3K9

黄曲霉是一种常见的腐生丝状真菌，在其生长过程中会产生高毒性的天然化合物黄曲霉毒素。黄曲霉毒素的合成可能会污染粮食作物，给农业经济造成巨大损失，通常受到表观遗传修饰（例如组蛋白乙酰转移酶）的调控。在本研究中，我们以黄曲霉为实验模型，通过同源重组构建了乙酰转移酶基因rtt109敲除菌株（△rtt109）及其互补菌株（△rtt109·com）。与野生型（WT）和△rtt109·com株相比，△rtt109的生长受到显着抑制。△rtt109的菌核变小，△rtt109产生的菌核量明显减少。△rtt109的分生孢子数明显减少，特别是在酵母提取物蔗糖（YES）固体培养基上。△rtt109在PDB液体培养基中合成的黄曲霉毒素的量显着减少。我们还发现△rtt109菌株对DNA损伤应力极为敏感。通过玉米种子感染实验，发现受影响玉米表面△rtt109的生长大大减少，气生菌丝数量明显减少，这与人工培养基上的结果一致。我们进一步发现H3K9是黄曲霉中Rtt109的乙酰化目标。总之，Rtt109参与了生长，分生孢子形成，菌核的产生，黄曲霉毒素的合成，环境胁迫反应，黄曲霉感染的调节。