Li Pan, Shen Shen, Jia Jingzhe, Sun Hehe, Zhu Hang, Wei Ning, Yu Bo, Sohail Aamir, Wu Di, Zeng Fanli, Hao Zhimin, Dong Jingao
State Key Laboratory of North China Crop Improvement, Hebei Agricultural University, Hebei 071001, China; College of Plant Protection, Hebei Agricultural University, Baoding, Hebei 071001, China.
Hebei Bioinformatic Utilization and Technological Innovation Center for Agricultural Microbes, Hebei Key Laboratory of Plant Physiology and Molecular Pathology, Hebei Agricultural University, College of Life Sciences, Baoding, Hebei 071001, China.
Int J Biol Macromol. 2024 May;266(Pt 2):131149. doi: 10.1016/j.ijbiomac.2024.131149. Epub 2024 Mar 29.
Northern corn leaf blight caused by Setosphaeria turcica is a major fungal disease responsible for significant reductions in maize yield worldwide. Eukaryotic type 2A protein phosphatase (PP2A) influences growth and virulence in a number of pathogenic fungi, but little is known about its roles in S. turcica. Here, we functionally characterized S. turcica StPP2A-C, which encodes the catalytic C subunit of StPP2A. StPP2A-C deletion slowed colony growth, conidial germination, and appressorium formation but increased conidiation, melanin biosynthesis, glycerol content, and disease lesion size on maize. These effects were associated with expression changes in genes related to calcium signaling, conidiation, laccase activity, and melanin and glycerol biosynthesis, as well as changes in intra- and extracellular laccase activity. A pull-down screen for candidate StPP2A-c interactors revealed an interaction between StPP2A-c and StLac1. Theoretical modeling and yeast two-hybrid experiments confirmed that StPP2A-c interacted specifically with the copper ion binding domain of StLac1 and that Cys267 of StPP2A-c was required for this interaction. StPP2A-C expression thus appears to promote hyphal growth and reduce pathogenicity in S. turcica, at least in part by altering melanin synthesis and laccase activity; these insights may ultimately support the development of novel strategies for biological management of S. turcica.
由大斑刚毛座腔菌引起的玉米大斑病是一种主要的真菌病害，在全球范围内导致玉米产量大幅下降。真核2A型蛋白磷酸酶（PP2A）影响许多致病真菌的生长和毒力，但关于其在大斑刚毛座腔菌中的作用知之甚少。在这里，我们对大斑刚毛座腔菌的StPP2A-C进行了功能表征，它编码StPP2A的催化C亚基。StPP2A-C的缺失减缓了菌落生长、分生孢子萌发和附着胞形成，但增加了分生孢子形成、黑色素生物合成、甘油含量以及玉米上的病斑大小。这些影响与钙信号、分生孢子形成、漆酶活性以及黑色素和甘油生物合成相关基因的表达变化有关，也与细胞内和细胞外漆酶活性的变化有关。对候选StPP2A-c相互作用蛋白的下拉筛选揭示了StPP2A-c与StLac1之间的相互作用。理论建模和酵母双杂交实验证实，StPP2A-c与StLac1的铜离子结合域特异性相互作用，并且这种相互作用需要StPP2A-c的Cys267。因此，StPP2A-C的表达似乎促进了大斑刚毛座腔菌的菌丝生长并降低了其致病性，至少部分是通过改变黑色素合成和漆酶活性实现的；这些见解最终可能有助于开发大斑刚毛座腔菌生物防治的新策略。
