Citric acid impairs type B trichothecene biosynthesis of <i>Fusarium graminearum</i> but enhances its growth and pigment biosynthesis: transcriptomic and proteomic analyses

<i>Fusarium graminearum</i> is a challenging phytopathogen that causes plant disasters worldwide, such as Fusarium head blight and ear rot in small grain crops like wheat and maize. Besides, the invasion of the fungus on plants is often accompanied by the production of health-threatening mycotoxins-trichothecenes. Therefore, the control of <i>Fusarium graminearum</i> has always been a hot area of research. However, currently, the prevalence of these plant diseases around the world and the mycotoxin accumulation beyond safety limits indicate the necessity for more related research. In the last decades, researchers have sought to identify the key substances associated with the growth, propagation, and mycotoxin production of the fungus, such as carbon and nitrogen sources. Organic acids have always been considered antifungal agents due to their abundant H+ content. However, their comprehensive impact on fungi has been rarely investigated. This research focused on the effect of citric acid, a type of crop exudate and a common heavy-metal chelator, on the metabolism of <i>Fusarium graminearum</i>. The result was expected to provide a theoretical basis for further studies on plants-soil-fungi interactions and the reasonable utilization of citric acid in agriculture.