Polarisome core component FgPea2 regulates FgBoi2-mediated polarized growth, pathogenicity and environmental stress in Fusarium graminearum

Abstract

Fusarium graminearum is a devastating plant pathogenic fungus that is the predominant causal agent of Fusarium head blight. Our previous study showed that the polarisome core component FgPea2 regulates polarized growth, deoxynivalenol (DON) production and virulence of F. graminearum. To further investigate the regulatory network of FgPea2, FgPea2-GFP pull down was performed and the anillin-related protein FgBoi2 was identified. FgBoi2 interacts with FgPea2 and exhibits partial co-localization at the hyphal tips of F. graminearum. Interestingly, FgPea2 regulates the polarized localization of FgBoi2-GFP, suggesting that FgPea2 functions upstream of FgBoi2. Furthermore, deletion of FgBOI2 resulted in a significant reduction in vegetative growth, conidiation, DON production and pathogenicity, as well as increased hyphal branching in F. graminearum. Structural analysis revealed that FgBoi2 contains SH3, SAM and PH domains. Further domain deletion experiments showed that the PH domain is crucial for vegetative growth, hyphae branching and polarized localization of FgBoi2. In addition, FgBoi2 negatively regulates the cell wall integrity and oxidative stress response pathways. FgPea2 and FgBoi2 modulate susceptibility to the fungicides tebuconazole, carbendazim, phenamacril and difenoconazole. In conclusion, this study shows that FgPea2 interacts with FgBoi2 and regulates FgBoi2-mediated polarized growth, stress tolerance, pathogenicity and fungicide resistance in F. graminearum.

Keywords

Fusarium graminearum / Polarisome / FgBoi2 / Polarized growth / Pathogenicity / Fungicide sensitivity

References

[1] Abou Ammar G, Tryono R, Döll K, Karlovsky P, Deising HB, Wirsel SG. Identification of ABC transporter genes of Fusarium graminearum with roles in azole tolerance and/or virulence. PLoS ONE, 2013, 8: e79042

[2] Abubakar YS, Sadiq IZ, Aarti A, Wang Z, Zheng W. Interplay of transport vesicles during plant-fungal pathogen interaction. Stress Biol, 2023, 3: 35

[3] Bender L, Lo HS, Lee H, Kokojan V, Peterson V, Bender A. Associations among PH and SH3 domain-containing proteins and Rho-type GTPases in yeast. J Cell Biol, 1996, 133: 879-894

[4] Bushnell W, Hazen B, Pritsch C, Leonard K (2003) Histology and physiology of Fusarium head blight. In: Leonard KJB, W. R (eds) Fusarium head blight of wheat and barley. APS Press, St. Paul, Minnesota, pp 44–83

[5] Catlett N, Lee B-N, Yoder O, Turgeon BG. Split-marker recombination for efficient targeted deletion of fungal genes. Fungal Genet News, 2003, 50: 9-11

[6] Chen Y, Kistler HC, Ma Z. Fusarium graminearum trichothecene mycotoxins: biosynthesis, regulation, and management. Annu Rev Phytopathol, 2019, 57: 15-39

[7] Chen S, Li P, Abubakar YS, Lü P, Li Y, Mao X, Zhang C, Zheng W, Wang Z, Lu GD, et al. . A feedback regulation of FgHtf1-FgCon7 loop in conidiogenesis and development of Fusarium graminearum. Int J Biol Macromol, 2024, 261: 129841

[8] Chenevert J, Valtz N, Herskowitz I. Identification of genes required for normal pheromone-induced cell polarization in Saccharomyces cerevisiae. Genetics, 1994, 136: 1287-1296

[9] Dean R, Van Kan JA, Pretorius ZA, Hammond-Kosack KE, Di Pietro A, Spanu PD, Rudd JJ, Dickman M, Kahmann R, Ellis J, et al. . The top 10 fungal pathogens in molecular plant pathology. Mol Plant Pathol, 2012, 13: 414-430

[10] Francl L, Shaner G, Bergstrom G, Gilbert J, Pedersen W, Dill-Macky R, Sweets L, Corwin B, Jin Y, Gallenberg D. Daily inoculum levels of Gibberella zeae on wheat spikes. Plant Dis, 1999, 83: 662-666

[11] Gardiner DM, Stephens AE, Munn AL, Manners JM. An ABC pleiotropic drug resistance transporter of Fusarium graminearum with a role in crown and root diseases of wheat. FEMS Microbiol Lett, 2013, 348: 36-45

[12] Gehrung S, Snyder M. The SPA2 gene of Saccharomyces cerevisiae is important for pheromone-induced morphogenesis and efficient mating. J Cell Biol, 1990, 111: 1451-1464

[13] Glomb O, Wu Y, Rieger L, Rüthnick D, Mulaw MA, Johnsson N (2020) The cell polarity proteins Boi1 and Boi2 direct an actin nucleation complex to sites of exocytosis in Saccharomyces cerevisiae. J Cell Sci 133:jcs237982. https://doi.org/10.1242/jcs.237982

[14] Hallett MA, Lo HS, Bender A. Probing the importance and potential roles of the binding of the PH-domain protein Boi1 to acidic phospholipids. BMC Cell Biol, 2002, 3: 16

[15] Harris SD, Read ND, Roberson RW, Shaw B, Seiler S, Plamann M, Momany M. Polarisome meets spitzenkörper: microscopy, genetics, and genomics converge. Eukaryot Cell, 2005, 4: 225-229

[16] He D, Li Y, Ma Q, Han L, Tang D, Miao Y. The phase-separating Magnaporthe oryzae MoSpa2 complex organizes actin nucleation centers for plant infection. Plant Cell, 2025, 37: koaf097

[17] Hong W. Snares and traffic. Biochim Biophys Acta, 2005, 1744: 120-144

[18] Hou ZM, Xue CY, Peng YL, Katan T, Kistler HC, Xu JR. A mitogen-activated protein kinase gene (MGV1) in Fusarium graminearum is required for female fertility, heterokaryon formation, and plant infection. Mol Plant Microbe Interact, 2002, 15: 1119-1127

[19] Jia ZW, Lv SX, Zhu J, Xia CY, Gao XD. Roles of the PH, coiled-coil and SAM domains of the yeast polarity protein Boi2 in polarity-site localization and function in polarized growth. Curr Genet, 2020, 66: 1101-1115

[20] Jiang C, Hei R, Yang Y, Zhang S, Wang Q, Wang W, Zhang Q, Yan M, Zhu G, Huang P, et al. . An orphan protein of Fusarium graminearum modulates host immunity by mediating proteasomal degradation of TaSnRK1α. Nat Commun, 2020, 11: 4382

[21] Jones LA, Sudbery PE. Spitzenkorper, exocyst, and polarisome components in Candida albicans hyphae show different patterns of localization and have distinct dynamic properties. Eukaryot Cell, 2010, 9: 1455-1465

[22] Knechtle P, Dietrich F, Philippsen P. Maximal polar growth potential depends on the polarisome component AgSpa2 in the filamentous fungus Ashbya gossypii. Mol Biol Cell, 2003, 14: 4140-4154

[23] Lee Y, Son H, Shin JY, Choi GJ, Lee YW. Genome-wide functional characterization of putative peroxidases in the head blight fungus Fusarium graminearum. Mol Plant Pathol, 2018, 19: 715-730

[24] Leeder AC, Turner G. Characterisation of Aspergillus nidulans polarisome component BemA. Fungal Genet Biol, 2008, 45: 897-911

[25] Leplat J, Friberg H, Abid M, Steinberg C. Survival of Fusarium graminearum , the causal agent of Fusarium head blight. A review. Agron Sustain Dev, 2013, 33: 97-111

[26] Liao Y, He F, Gong T, Bi E, Gao XD. Msb1 interacts with Cdc42, Boi1, and Boi2 and may coordinate Cdc42 and Rho1 functions during early stage of bud development in budding yeast. PLoS ONE, 2013, 8: e66321

[27] Lichius A, Yanez-Gutierrez ME, Read ND, Castro-Longoria E. Comparative live-cell imaging analyses of SPA-2, BUD-6 and BNI-1 in Neurospora crassa reveal novel features of the filamentous fungal polarisome. PLoS ONE, 2012, 7: e30372

[28] Liu B, Larsson L, Caballero A, Hao X, Oling D, Grantham J, Nyström T. The polarisome is required for segregation and retrograde transport of protein aggregates. Cell, 2010, 140: 257-267

[29] Liu Y, Tian Y, Peng H, Zhang F, Huang X, Chen G, Zhou L, Che Z. Design, synthesis, and anti-oomycete and antifungal activities of novel paeonol derivatives containing a pyrazole ring. J Agric Food Chem, 2025, 73: 9533-9540

[30] Lou Y, Zhang J, Wang G, Fang W, Wang S, Abubakar YS, Zhou J, Wang Z, Zheng W. Genome-wide characterization of PX domain-containing proteins involved in membrane trafficking-dependent growth and pathogenicity of Fusarium graminearum. Mbio, 2021, 12: e0232421

[31] Luo Z, Mao X, Peng M, Huang C, Liang J, Xiao Y, Abubakar YS, Zheng W, Xiong Y, Wang Z, et al. . The phenol-2-monooxygenase FgPhm1 regulates DON synthesis, pathogenicity and environmental stress response in Fusarium graminearum. Virulence, 2025, 16: 2563017

[32] Mao X, Li L, Abubakar YS, Li Y, Luo Z, Chen M, Zheng W, Wang Z, Zheng H. Nucleoside diphosphate kinase FgNdpk is required for DON production and pathogenicity by regulating the growth and toxisome formation of Fusarium graminearum. J Agric Food Chem, 2024, 72: 9637-9646

[33] Masgrau A, Battola A, Sanmartin T, Pryszcz LP, Gabaldón T, Mendoza M. Distinct roles of the polarity factors Boi1 and Boi2 in the control of exocytosis and abscission in budding yeast. Mol Biol Cell, 2017, 28: 3082-3094

[34] Matsui Y, Matsui R, Akada R, Toh-e A. Yeast src homology region 3 domain-binding proteins involved in bud formation. J Cell Biol, 1996, 133: 865-878

[35] Mesterházy Á, Tóth B, Varga M, Bartók T, Szabó-Hevér Á, Farády L, Lehoczki-Krsjak S. Role of fungicides, application of nozzle types, and the resistance level of wheat varieties in the control of Fusarium head blight and deoxynivalenol. Toxins, 2011, 3: 1453-1483

[36] Meyer V, Arentshorst M, van den Hondel CAMJJ, Ram AFJ. The polarisome component SpaA localises to hyphal tips of Aspergillus niger and is important for polar growth. Fungal Genet Biol, 2008, 45: 152-164

[37] Miao P, Mao X, Chen S, Abubakar YS, Li Y, Zheng W, Zhou J, Wang Z, Zheng H. The mitotic exit mediated by small GTPase Tem1 is essential for the pathogenicity of Fusarium graminearum. PLoS Pathog, 2023, 19: e1011255

[38] Moonjely S, Ebert M, Paton-Glassbrook D, Noel ZA, Roze L, Shay R, Watkins T, Trail F. Update on the state of research to manage Fusarium head blight. Fungal Genet Biol, 2023, 169: 103829

[39] Motizuki M, Xu Z. Importance of polarisome proteins in reorganization of actin cytoskeleton at low pH in Saccharomyces cerevisiae. J Biochem, 2009, 146: 705-712

[40] O’Mara SP, Broz K, Schwister EM, Singh L, Dong Y, Elmore JM, Kistler HC. The Fusarium graminearum transporters Abc1 and Abc6 are important for xenobiotic resistance, trichothecene accumulation, and virulence to wheat. Phytopathology, 2023, 113: 1916-1923

[41] Proctor RH, Hohn TM, McCormick SP. Reduced virulence of Gibberella zeae caused by disruption of a trichothecene toxin biosynthetic gene. Mol Plant Microbe Interact, 1995, 8: 593-601

[42] Ran Y, Li S, Wang YJ, Liang JH, Jiang W, Yu MJ. AI-accelerated identification of novel antimicrobial peptides for inhibiting Fusarium graminearum. J Agric Food Chem, 2025, 73: 17471-17482

[43] Riquelme M. Tip growth in filamentous fungi: a road trip to the apex. Annu Rev Microbiol, 2013, 67: 587-609

[44] Sagot I, Klee SK, Pellman D. Yeast formins regulate cell polarity by controlling the assembly of actin cables. Nat Cell Biol, 2002, 4: 42-50

[45] Sekiya-Kawasaki M, Abe M, Saka A, Watanabe D, Kono K, Minemura-Asakawa M, Ishihara S, Watanabe T, Ohya Y. Dissection of upstream regulatory components of the Rho1p effector, 1,3-beta-glucan synthase, in Saccharomyces cerevisiae. Genetics, 2002, 162: 663-676

[46] Shang S, He Y, Zhao R, Li H, Fang Y, Hu Q, Fan Y, Wang Y, Zhou X, Wang P, et al. . Fumarylacetoacetate hydrolase targeted by a Fusarium graminearum effector positively regulates wheat FHB resistance. Nat Commun, 2025, 16: 5582

[47] Sheu YJ, Santos B, Fortin N, Costigan C, Snyder M. Spa2p interacts with cell polarity proteins and signaling components involved in yeast cell morphogenesis. Mol Cell Biol, 1998, 18: 4053-4069

[48] Sulpizio A, Herpin L, Gingras R, Liu W, Bretscher A (2022) Generation and characterization of conditional yeast mutants affecting each of the 2 essential functions of the scaffolding proteins Boi1/2 and Bem1. G3 (Bethesda) 12:jkac273. https://doi.org/10.1093/g3journal/jkac273

[49] Sun D, Li C, Zhao L, Yang J, Li H, Duan K, Wang C, Wang G. FgMsn2, a zinc finger transcription factor, regulates stress responses, pathogenicity and metabolism in wheat scab fungus Fusarium graminearum. Stress Biol, 2025, 5: 54

[50] Tessarz P, Schwarz M, Mogk A, Bukau B. The yeast AAA+ chaperone Hsp104 is part of a network that links the actin cytoskeleton with the inheritance of damaged proteins. Mol Cell Biol, 2009, 29: 3738-3745

[51] Teyra J, Huang H, Jain S, Guan X, Dong A, Liu Y, Tempel W, Min J, Tong Y, Kim PM, et al. . Comprehensive analysis of the human SH3 domain family reveals a wide variety of non-canonical specificities. Structure, 2017, 25: 1598-1610.e1593

[52] Tini F, Beccari G, Onofri A, Ciavatta E, Gardiner DM, Covarelli L. Fungicides may have differential efficacies towards the main causal agents of Fusarium head blight of wheat. Pest Manag Sci, 2020, 76: 3738-3748

[53] Valtz N, Herskowitz I. Pea2 protein of yeast is localized to sites of polarized growth and is required for efficient mating and bipolar budding. J Cell Biol, 1996, 135: 725-739

[54] Virag A, Harris Steven D. Functional characterization of Aspergillus nidulans homologues of Saccharomyces cerevisiae Spa2 and Bud6. Eukaryot Cell, 2006, 5: 881-895

[55] Wang C, Cong W, Yang L, Hou Y. A novel field resistance mechanism: two structural variations in FgOs1 confer ultrahigh fludioxonil resistance in Fusarium graminearum without disrupting FgOs1 transcription or translation. J Agric Food Chem, 2025, 73: 18669-18679

[56] Wu L, Chen F, Wang P, Xu C, Wen W, Hahn M, Zhou M, Hou Y. Application of dsRNA of FgPMA1 for disease control on Fusarium graminearum. J Integr Agric, 2025, 24: 2285-2298

[57] Xie Y, Miao Y (2021) Polarisome assembly mediates actin remodeling during polarized yeast and fungal growth. J Cell Sci 134:jcs247916. https://doi.org/10.1242/jcs.247916

[58] Xu L, Wang M, Tang G, Ma Z, Shao W. The endocytic cargo adaptor complex is required for cell-wall integrity via interacting with the sensor FgWsc2B in Fusarium graminearum. Curr Genet, 2019, 65: 1071-1080

[59] Xu M, Wang Q, Wang G, Zhang X, Liu H, Jiang C. Combatting Fusarium head blight: advances in molecular interactions between Fusarium graminearum and wheat. Phytopathology Res, 2022, 4: 37

[60] Xu C, Guo M, Han X, Ren C, Liu C, Fu W, Qi J, Ge Z, Ma Z, Chen Y. Fungal pathogen diversity and fungicide resistance assessment in Fusarium crown rot of wheat in the Huanghuai region of China. J Agric Food Chem, 2025, 73: 2299-2311

[61] Yuan Y, Zhang M, Li J, Yang C, Abubakar YS, Chen X, Zheng W, Wang Z, Zheng H, Zhou J. The small GTPase FgRab1 plays indispensable roles in the vegetative growth, vesicle fusion, autophagy and pathogenicity of Fusarium graminearum. Int J Mol Sci, 2022, 23(2): 895

[62] Yun Y, Liu Z, Zhang J, Shim WB, Chen Y, Ma Z. The MAPKK FgMkk1 of Fusarium graminearum regulates vegetative differentiation, multiple stress response, and virulence via the cell wall integrity and high-osmolarity glycerol signaling pathways. Environ Microbiol, 2014, 16: 2023-2037

[63] Zhang XZ, Chen S, Abubakar YS, Mao XZ, Miao PF, Wang ZH, Zhou J, Zheng HW. FgGyp8 as a putative FgRab1 GAP is required for growth and pathogenesis by regulating FgSnc1-mediated secretory vesicles fusion in Fusarium graminearum. J Integr Agr, 2023, 22: 3444-3457

[64] Zhang F, Zhang H, Liu J, Ren X, Ding Y, Sun F, Zhu Z, He X, Zhou Y, Bai G, Ni Z, Sun Q, Su Z (2024) Fhb9, a major QTL for Fusarium head blight resistance improvement in wheat. J Integr Agric 24:4127-4137. https://doi.org/10.1016/j.jia.2024.03.045

[65] Zheng H, Zheng W, Wu C, Yang J, Xi Y, Xie Q, Zhao X, Deng X, Lu G, Li G, et al. . Rab GTPases are essential for membrane trafficking-dependent growth and pathogenicity in Fusarium graminearum. Environ Microbiol, 2015, 17: 4580-4599

[66] Zheng W, Lin Y, Fang W, Zhao X, Lou Y, Wang G, Zheng H, Liang Q, Abubakar YS, Olsson S, et al. . The endosomal recycling of FgSnc1 by FgSnx41-FgSnx4 heterodimer is essential for polarized growth and pathogenicity in Fusarium graminearum. New Phytol, 2018, 219: 654-671

[67] Zheng H, Li L, Yu Z, Yuan Y, Zheng Q, Xie Q, Li G, Abubakar YS, Zhou J, Wang Z, et al. . FgSpa2 recruits FgMsb3, a Rab8 GAP, to the polarisome to regulate polarized trafficking, growth and pathogenicity in Fusarium graminearum. New Phytol, 2021, 229: 1665-1683

Funding

National Natural Science Foundation of China(32470209)

Natural Science Foundation of Fujian Province(2024J02030)

The project of Minjiang University(MJY19019)

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The Author(s)