Díaz-Sánchez Violeta, Castrillo Marta, García-Martínez Jorge, Avalos Javier, Limón M Carmen
Department of Genetics, Faculty of Biology, University of Seville, 41012 Seville, Spain.
J Fungi (Basel). 2024 Mar 8;10(3):203. doi: 10.3390/jof10030203.
The phytopathogenic fungus has a rich secondary metabolism which includes the synthesis of very different metabolites in response to diverse environmental cues, such as light or nitrogen. Here, we focused our attention on fusarins, a class of mycotoxins whose synthesis is downregulated by nitrogen starvation. Previous data showed that mutants of genes involved in carotenoid regulation (, encoding a RING finger protein repressor), light detection (, White Collar photoreceptor), and cAMP signaling (AcyA, adenylate cyclase) affect the synthesis of different metabolites. We studied the effect of these mutations on fusarin production and the expression of the gene, which encodes the key polyketide synthase of the pathway. We found that the three proteins are positive regulators of fusarin synthesis, especially WcoA and AcyA, linking light regulation to cAMP signaling. Genes for two other photoreceptors, the cryptochrome CryD and the Vivid flavoprotein VvdA, were not involved in fusarin regulation. In most cases, there was a correspondence between fusarin production and mRNA, indicating that regulation is mainly exerted at the transcriptional level. We conclude that fusarin synthesis is subject to a complex control involving regulators from different signaling pathways.
植物病原真菌具有丰富的次生代谢，包括响应不同环境线索（如光或氮）合成非常不同的代谢产物。在这里，我们将注意力集中在镰刀菌素上，这是一类霉菌毒素，其合成在氮饥饿时会下调。先前的数据表明，参与类胡萝卜素调控的基因（编码一种环状指蛋白阻遏物）、光检测（白领光感受器）和cAMP信号传导（AcyA，腺苷酸环化酶）的突变体影响不同代谢产物的合成。我们研究了这些突变对镰刀菌素产生以及编码该途径关键聚酮合酶的基因表达的影响。我们发现这三种蛋白质是镰刀菌素合成的正调控因子，尤其是WcoA和AcyA，它们将光调控与cAMP信号传导联系起来。另外两个光感受器隐花色素CryD和Vivid黄素蛋白VvdA的基因不参与镰刀菌素调控。在大多数情况下，镰刀菌素产生与mRNA之间存在对应关系，表明调控主要在转录水平发挥作用。我们得出结论，镰刀菌素合成受到涉及来自不同信号通路的调控因子的复杂控制。
