Journal of Integrative Agriculture ›› 2025, Vol. 24 ›› Issue (11): 4310-4323.DOI: 10.1016/j.jia.2024.09.033

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GPI锚定通过影响细胞壁完整性、免疫逃避以及ChFEM1蛋白膜定位来调控玉米小斑病菌致病力

  

  • 收稿日期:2024-07-04 修回日期:2024-09-26 接受日期:2024-08-30 出版日期:2025-11-20 发布日期:2025-10-13

Glycosylphosphatidylinositol (GPI) anchoring controls cell wall integrity, immune evasion and surface localization of ChFEM1 for infection of Cochlibolus heterostrophus

Hong Hu1*, Tiangu Liu1*, Xinyun Xie1, Fuyan Li1, Caiyun Liu2, Jintao Jiang1, Zhigang Li3, Xiaolin Chen1#   

  1. 1 State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China

    2 Guangdong Provincial Key Laboratory of High Technology for Plant Protection, Plant Protection Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China

    3 Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests of Ministry of Education, College of Plant Protection, Hainan University, Haikou 570000, China

  • Received:2024-07-04 Revised:2024-09-26 Accepted:2024-08-30 Online:2025-11-20 Published:2025-10-13
  • About author:#Correspondence Xiaolin Chen, E-mail: chenxiaolin@mail.hzau.edu.cn * These authors contributed equally to this study.
  • Supported by:
    This work was supported by the Fundamental Research Funds for the Central Universities, China (2021ZKPY007).

摘要:

GPI(糖基磷脂酰肌醇)锚定修饰在不同物种中发挥着粘附、分子吸收、信号转导和保护、细胞壁组分的合成和重组以及细胞壁蛋白的锚定等作用,且对真菌的生长发育和致病过程发挥着重要作用。目前关于 GPI 锚定修饰在真菌中虽然已有了初步研究,但其生物学功能和致病调控机制尚需深入揭示。本文对玉米小斑病菌 (Cochlibolus heterostrophus) GPI 锚定修饰的生物学功能和致病机制进行研究。首先,探究了 GPI 锚生物合成通路关键蛋白 ChGPI7 在玉米小斑病菌生长发育和致病过程中的功能及其参与致病的调控机制。结果表明,GPI锚定蛋白在玉米小斑菌的菌丝、附着胞和侵染菌丝中广泛表达。玉米小班菌ChGPI7基因的缺失会导致玉米小斑菌生长速度和分生孢子产孢能力显著下降。同时玉米小班菌ChGPI7基因敲除体∆Chgpi7的附着胞形成和侵染过程明显受阻,导致其致病力显著下降。∆Chgpi7敲除体还表现出严重的细胞壁完整性缺陷。ChGPI7基因的缺失和HF pyridine处理都会导致玉米小斑菌的细胞壁蛋白丰度减弱和几丁质的暴露,说明GPI锚定蛋白可以保护几丁质不被宿主免疫识别。在玉米小斑菌中,共有124个蛋白质被预测为GPI锚定修饰蛋白,其中包括一种假定的细胞壁糖蛋白ChFEM1,并发现其功能受 GPI 锚定修饰调控。缺失ChFEM1也会导致玉米小斑菌的致病力显著下降、侵染结构和细胞壁完整性的缺陷。我们的研究进一步发现,在玉米小斑菌中,ChGPI7调控ChFEM1蛋白的细胞壁定位和蛋白丰度。综合以上结果可以表明,GPI锚定修饰调节了玉米小斑菌的细胞壁完整性,免疫逃避和ChFEM1蛋白的细胞壁定位。研究结果为深入研究玉米小斑病菌的致病机制提供了理论基础,同时为开发防治玉米小斑病菌的新型药剂提供了潜在的靶标。

Abstract:

Glycosylphosphatidylinositol (GPI) anchoring represents a fundamental post-translational modification in eukaryotic cells.  In fungi, this modification facilitates diverse biological functions through protein targeting to the cell wall, yet research on its roles in plant pathogenic fungi remains limited.  This study elucidates the function of GPI anchoring in the maize fungal pathogen Cochlibolus heterostrophus.  The research demonstrates widespread accumulation of GPI-anchored proteins in hyphae, appressorium and infection hyphae of Cheterostrophus.  Deletion of ChGPI7, encoding a crucial enzyme in GPI anchor biosynthesis, substantially reduced vegetative growth, conidiation, and virulence through impaired appressorium formation and invasive growth.  The ΔChgpi7 mutants exhibited marked deficiencies in cell wall integrity, leading to decreased stress resistance.  Both ChGPI7 deletion and hydro fluoric acid (HF) pyridine treatment eliminated cell wall GPI-anchored proteins and exposed chitin, indicating that GPI-anchored proteins shield chitin from host immune recognition.  Analysis identified 124 predicted GPI-anchored proteins in Cheterostrophus, including the putative cell wall glycoprotein ChFEM1.  The deletion of ChFEM1 similarly reduced virulence and compromised infection structures and cell wall integrity.  Additionally, ChGPI7 influenced both the cell wall localization and protein abundance of ChFEM1.  These findings demonstrate that GPI anchoring mediates cell wall integrity and immune evasion during Cheterostrophus infection.


Key words: Cochlibolus heterostrophus ,  GPI anchor ,  immune evasion ,  cell wall integrity ,  cell wall protein ,  fungal infection