Li Pan, Sun Hehe, Han Xinpeng, Long Feng, Shen Shen, Li Zhiyong, Zeng Fanli, Hao Zhimin, Dong Jingao
State Key Laboratory of North China Crop Improvement, Hebei Agricultural University, Baoding, Hebei 071001, China.
College of Plant Protection, Hebei Agricultural University, Baoding, Hebei 071001, China.
J Agric Food Chem. 2023 Dec 13;71(49):19568-19580. doi: 10.1021/acs.jafc.3c06635. Epub 2023 Nov 29.
Septins are a conserved group of GTP-binding proteins found in all eukaryotes and are the fourth-most abundant cytoskeletal proteins. Septins of some pathogenic fungi are involved in morphological changes related to infection. Our previous studies have identified four core septins (-) in , the causal agent of northern corn leaf blight, while only is significantly upregulated during the invasive process. We therefore used forchlorfenuron (FCF), the specific inhibitor of septin, and Δ knockout mutants to further clarify the role of septins in pathogenicity. FCF treatment caused a dose-dependent reduction in colony growth, delayed the formation of infection structures, and reduced the penetration ability. Δ knockout mutants displayed abnormal mycelium morphology, slow mycelial growth, conidiation deficiency, delayed appressorium development, and weakened pathogenicity. deletion also broke cell wall integrity, altered chitin distribution, decreased the melanin content, and disrupted normal nuclear localization. A transcriptomic comparison revealed that genes differentially expressed between Δ and WT were enriched in terms of ribosomes, protein translation, membrane components, and transmembrane transport activities. Our results demonstrate that is required for morphology and pathogenicity in , making it a promising target for the development of novel fungicides.
Septin蛋白是一类在所有真核生物中都存在的保守的GTP结合蛋白，是细胞骨架蛋白中含量第四丰富的蛋白。一些致病真菌的Septin蛋白与感染相关的形态变化有关。我们之前的研究已经在玉米大斑病菌（引起玉米北方叶斑病的病原体）中鉴定出四个核心Septin蛋白（-），而在侵染过程中只有显著上调。因此，我们使用了Septin蛋白的特异性抑制剂氯吡脲（FCF）和Δ敲除突变体来进一步阐明Septin蛋白在玉米大斑病菌致病性中的作用。FCF处理导致玉米大斑病菌落生长呈剂量依赖性减少，感染结构形成延迟，穿透能力降低。Δ敲除突变体表现出异常的菌丝形态、菌丝生长缓慢、分生孢子形成缺陷、附着胞发育延迟和致病性减弱。缺失还破坏了细胞壁完整性，改变了几丁质分布，降低了黑色素含量，并扰乱了正常的核定位。转录组比较显示，Δ和野生型之间差异表达的基因在核糖体、蛋白质翻译、膜成分和跨膜运输活动方面富集。我们的结果表明，Septin蛋白是玉米大斑病菌形态和致病性所必需的，使其成为新型杀菌剂开发的一个有前景的靶点。
