State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwestern A&F University, Yangling, Shaanxi, 712100, China.
Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, 47907, USA.
Environ Microbiol. 2015 Aug;17(8):2762-76. doi: 10.1111/1462-2920.12747. Epub 2015 Mar 2.
In eukaryotic cells, MADS-box genes are known to play major regulatory roles in various biological processes by combinatorial interactions with other transcription factors. In this study, we functionally characterized the FgMCM1 MADS-box gene in Fusarium graminearum, the causal agent of wheat and barley head blight. Deletion of FgMCM1 resulted in the loss of perithecium production and phialide formation. The Fgmcm1 mutant was significantly reduced in virulence, deoxynivalenol biosynthesis and conidiation. In yeast two-hybrid assays, FgMcm1 interacted with Mat1-1-1 and Fst12, two transcription factors important for sexual reproduction. Whereas Fgmcm1 mutants were unstable and produced stunted subcultures, Fgmcm1 mat1-1-1 but not Fgmcm1 fst12 double mutants were stable. Furthermore, spontaneous suppressor mutations occurred frequently in stunted subcultures to recover growth rate. Ribonucleic acid sequencing analysis indicated that a number of sexual reproduction-related genes were upregulated in stunted subcultures compared with the Fgmcm1 mutant, which was downregulated in the expression of genes involved in pathogenesis, secondary metabolism and conidiation. We also showed that culture instability was not observed in the Fvmcm1 mutants of the heterothallic Fusarium verticillioides. Overall, our data indicate that FgMcm1 plays a critical role in the regulation of cell identity, sexual and asexual reproduction, secondary metabolism and pathogenesis in F. graminearum.
在真核细胞中，MADS-box 基因通过与其他转录因子的组合相互作用，在各种生物过程中发挥主要的调节作用。在这项研究中，我们对禾谷镰孢菌（导致小麦和大麦赤霉病的病原体）中的 FgMCM1 MADS-box 基因进行了功能表征。FgMCM1 的缺失导致产子囊果和产分生孢子梗的能力丧失。Fgmcm1 突变体的毒力、脱氧雪腐镰刀菌烯醇生物合成和产分生孢子能力显著降低。酵母双杂交实验表明，FgMcm1 与 Mat1-1-1 和 Fst12 相互作用，Mat1-1-1 和 Fst12 是性生殖中重要的转录因子。虽然 Fgmcm1 突变体不稳定，产生生长不良的亚培养物，但 Fgmcm1 mat1-1-1 而不是 Fgmcm1 fst12 双突变体是稳定的。此外，在生长不良的亚培养物中经常发生自发抑制突变，以恢复生长速率。核糖核酸测序分析表明，与 Fgmcm1 突变体相比，许多与有性生殖相关的基因在生长不良的亚培养物中上调，而参与发病机制、次生代谢和产分生孢子的基因表达下调。我们还表明，在异宗配合的轮枝镰孢菌的 Fvmcm1 突变体中没有观察到培养不稳定。总的来说，我们的数据表明，FgMcm1 在禾谷镰孢菌细胞身份、有性和无性生殖、次生代谢和发病机制的调控中起着关键作用。
