Abstract
Background
Wheat is one of the most important staple crops produced worldwide. Its susceptibility to plant diseases reduces its production significantly. One of the most important diseases of wheat is septoria tritici blotch, a devastating disease observed in fields with wet and temperate conditions. Z. tritici secretes effector proteins to influence the host’s defense mechanisms, as is typical of plant pathogens. In this investigation, we evaluated the pathogenicity of some Zymoseptoria tritici effector candidate genes having a signal peptide for secretion with no known function.
Methods and results
Three genes named Mycgr3G104383, Mycgr3G104444 and Mycgr3G105826 were knocked out separately through homologous recombination, generating Z. tritici IPO323 mutants lacking the functional copy of the corresponding genes. While KO1 and KO3 mutants did not show any significant differences during phenotypic and virulence investigations, the KO2 mutant generated exclusively macropycnidiospores in artificial media, different from wild-type IPO323 which produce only micropycidiospores. The mycelial growth capability of KO2 was also severely attenuated in all of the investigated growth conditions. These changes were observed independent of growth media and growth temperatures, implying that changes were genetic and inherited through generations. Virulence of knockout mutants in wheat leaves was observed to be similar to the wild-type IPO323.
Conclusion
Understanding the biology of Z. tritici and its interactions with wheat will reveal new strategies to fight septoria tritici blotch, enabling breeding wheat cultivars resistant to a broader spectrum of Z. tritici strains. Furthermore, gene knockout via homologous recombination proved to be a powerful tool for discovering novel gene functions.
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Data Availability
All data needed to conduct this study is provided within the manuscript.
References
Savary S, Willocquet L, Pethybridge SJ, Esker P, McRoberts N, Nelson A (2019) The global burden of pathogens and pests on major food crops. Nat Ecol Evol 3(3):430–439. https://doi.org/10.1038/s41559-018-0793-y
FAOSTAT (2020) ; http://www.fao.org/faostat/en. Accesed 03 March 2022
Ray DK, Mueller ND, West PC, Foley JA (2013) Yield trends are insufficient to double global crop production by 2050. PLoS ONE 8(6):e66428. https://doi.org/10.1371/journal.pone.0066428
Ficke A, Cowger C, Bergstrom G, Brodal G (2018) Understanding yield loss and pathogen biology to improve disease management: Septoria nodorum blotch-a case study in wheat. Plant Dis 102(4):696–707. https://doi.org/10.1094/PDIS-09-17-1375-FE
Eyal Z, Scharen AL, Prescott JM, van Ginkel M (1987) The Septoria diseases of wheat: concepts and methods of disease management. CIMMYT, Mexico, D.F., p 46
Fones H, Gurr S (2015) The impact of Septoria tritici Blotch disease on wheat: An EU perspective. Fungal Genet Biol 79:3–7. https://doi.org/10.1016/j.fgb.2015.04.004
Shetty NP, Mehrabi R, Lütken H, Haldrup A, Kema GH, Collinge DB, Jørgensen HJL (2007) Role of hydrogen peroxide during the interaction between the hemibiotrophic fungal pathogen Septoria tritici and wheat. New Phytol 174(3):637–647. https://doi.org/10.1111/j.1469-8137.2007.02026.x
Adhikari TB, Balaji B, Breeden J, Goodwin SB (2007) Resistance of wheat to Mycosphaerella graminicola involves early and late peaks of gene expression. Physiol Mol Plant Pathol 71(1–3):55–68. https://doi.org/10.1016/j.pmpp.2007.10.004
Orton ES, Deller S, Brown JK (2011) Mycosphaerella graminicola: from genomics to disease control. Mol Plant Pathol 12(5):413–424. https://doi.org/10.1111/j.1364-3703.2010.00688.x
Mehrabi R, Zwiers LH, de Waard MA, Kema GH (2006) MgHog1 regulates dimorphism and pathogenicity in the fungal wheat pathogen Mycosphaerella graminicola. Mol Plant Microbe Interact 19(11):1262–1269. https://doi.org/10.1094/MPMI-19-1262
Steinberg G (2015) Cell biology of Zymoseptoria tritici: Pathogen cell organization and wheat infection. Fungal Genet Biol 79:17–23. https://doi.org/10.1016/j.fgb.2015.04.002
Mustafa Z (2020) Distribution of Septoria tritici blotch disease agent Zymoseptoria tritici mating type idiomorphs in Turkey. Bitki Koruma Bülteni 60(3):33–38. https://doi.org/10.16955/bitkorb.656918
Ravensdale M, Nemri A, Thrall PH, Ellis JG, Dodds PN (2011) Co-evolutionary interactions between host resistance and pathogen effector genes in flax rust disease. Mol Plant Pathol 12(1):93–102. https://doi.org/10.1111/j.1364-3703.2010.00657.x
Boller T, He SY (2009) Innate immunity in plants: an arms race between pattern recognition receptors in plants and effectors in microbial pathogens. Science 324(5928):742–744. https://doi.org/10.1126/science.117164
Sperschneider J, Gardiner DM, Dodds PN, Tini F, Covarelli L, Singh KB et al (2016) EffectorP: predicting fungal effector proteins from secretomes using machine learning. New Phytol 210(2):743–761. https://doi.org/10.1111/nph.13794
Kamoun S (2006) A catalogue of the effector secretome of plant pathogenic oomycetes. Annu Rev Phytopathol 44:41–60. https://doi.org/10.1146/annurev.phyto.44.070505.143436
Rovenich H, Boshoven JC, Thomma BP (2014) Filamentous pathogen effector functions: of pathogens, hosts and microbiomes. Curr Opin Plant Biol 20:96–103. https://doi.org/10.1016/j.pbi.2014.05.001
Marshall R, Kombrink A, Motteram J, Loza-Reyes E, Lucas J, Hammond-Kosack KE et al (2011) Analysis of two in planta expressed LysM effector homologs from the fungus Mycosphaerella graminicola reveals novel functional properties and varying contributions to virulence on wheat. Plant Physiol 156(2):756–769. https://doi.org/10.1104/pp.111.176347
M’Barek SB, Cordewener JH, Ghaffary SMT, van der Lee TA, Liu Z, Gohari AM et al (2015) FPLC and liquid-chromatography mass spectrometry identify candidate necrosis-inducing proteins from culture filtrates of the fungal wheat pathogen Zymoseptoria tritici. Fungal Genet Biol 79:54–62. https://doi.org/10.1016/j.fgb.2015.03.015
Zhong Z, Marcel TC, Hartmann FE, Ma X, Plissonneau C, Zala M et al (2017) A small secreted protein in Zymoseptoria tritici is responsible for avirulence on wheat cultivars carrying the Stb6 resistance gene. New Phytol 214(2):619–631. https://doi.org/10.1111/nph.14434
Morais do Amaral A, Antoniw J, Rudd JJ, Hammond-Kosack KE (2012) Defining the predicted protein secretome of the fungal wheat leaf pathogen Mycosphaerella graminicola. PLoS ONE 7(12):e49904. https://doi.org/10.1371/journal.pone.0049904
Goodwin SB, M’Barek SB, Dhillon B, Wittenberg AH, Crane CF, Hane JK et al (2011) Finished genome of the fungal wheat pathogen Mycosphaerella graminicola reveals dispensome structure, chromosome plasticity, and stealth pathogenesis. PLoS Genet 7(6):e1002070. https://doi.org/10.1371/journal.pgen.1002070
Rudd JJ, Kanyuka K, Hassani-Pak K, Derbyshire M, Andongabo A, Devonshire J et al (2015) Transcriptome and metabolite profiling of the infection cycle of Zymoseptoria tritici on wheat reveals a biphasic interaction with plant immunity involving differential pathogen chromosomal contributions and a variation on the hemibiotrophic lifestyle definition. Plant Physiol 167(3):1158–1185. https://doi.org/10.1104/pp.114.255927
Holsters M, De Waele D, Depicker A, Messens E, Van Montagu M, Schell J (1978) Transfection and transformation of Agrobacterium tumefaciens. Mol Gen Genet MGG 163(2):181–187. https://doi.org/10.1007/BF00267408
Zwiers LH, De Waard MA (2001) Efficient Agrobacterium tumefaciens-mediated gene disruption in the phytopathogen Mycosphaerella graminicola. Curr Genet 39(5):388–393. https://doi.org/10.1007/s002940100216
Turgay EB, Büyük O, Ölmez F, Akan K, Yıldırım AF (2017) The reaction of some Turkish bread and durum wheat cultivars against to Zymoseptoria tritici (Desm. Quaedvlieg & Crous). Works of the Faculty of Agriculture and Food Sciences, University of Sarajevo, Vol. LXII, No. 67/2. Sarajevo, Bosnia and Herzegovina, pp 231–239
Townsend GR, Heuberger JW (1943) Methods for estimating losses caused by diseases in fungicide experiments. The Plant Disease Reporter 27:340–343
Francisco CS, Ma X, Zwyssig MM, McDonald BA, Palma-Guerrero J (2019) Morphological changes in response to environmental stresses in the fungal plant pathogen Zymoseptoria tritici. Sci Rep 9(1):1–18. https://doi.org/10.1038/s41598-019-45994-3
Yemelin A, Brauchler A, Jacob S, Laufer J, Heck L, Foster AJ et al (2017) Identification of factors involved in dimorphism and pathogenicity of Zymoseptoria tritici. PLoS ONE 12(8):e0183065. https://doi.org/10.1371/journal.pone.0183065
Tiley AM, Foster GD, Bailey AM (2018) Exploring the genetic regulation of asexual sporulation in Zymoseptoria tritici. Front Microbiol 9:1859. https://doi.org/10.3389/fmicb.2018.01859
Tiley AM, White HJ, Foster GD, Bailey AM (2019) The ZtvelB gene is required for vegetative growth and sporulation in the wheat pathogen Zymoseptoria tritici. Front Microbiol 2210. https://doi.org/10.3389/fmicb.2019.02210
Mehrabi R, Van der Lee T, Waalwijk C, Kema GH (2006) MgSlt2, a cellular integrity MAP kinase gene of the fungal wheat pathogen Mycosphaerella graminicola, is dispensable for penetration but essential for invasive growth. Mol Plant Microbe Interact 19(4):389–398. https://doi.org/10.1094/MPMI-19-0389
Mehrabi R, M’Barek SB, van der Lee TA, Waalwijk C, de Wit PJ, Kema GH (2009) Gα and Gβ proteins regulate the cyclic AMP pathway that is required for development and pathogenicity of the phytopathogen Mycosphaerella graminicola. Eukaryot Cell 8(7):1001–1013. https://doi.org/10.1128/EC.00258-08
Lendenmann MH, Croll D, Stewart EL, McDonald BA (2014) Quantitative trait locus mapping of melanization in the plant pathogenic fungus Zymoseptoria tritici. G3: Genes, Genomes. Genetics 4(12):2519–2533. https://doi.org/10.1534/g3.114.015289
Butler MJ, Day AW (1998) Fungal melanins: a review. Can J Microbiol 44(12):1115–1136. https://doi.org/10.1139/w98-119
Lendenmann MH, Croll D, McDonald BA (2015) QTL mapping of fungicide sensitivity reveals novel genes and pleiotropy with melanization in the pathogen Zymoseptoria tritici. Fungal Genet Biol 80:53–67. https://doi.org/10.1016/j.fgb.2015.05.001
Anderson JB, Sirjusingh C, Parsons AB, Boone C, Wickens C, Cowen LE, Kohn LM (2003) Mode of selection and experimental evolution of antifungal drug resistance in Saccharomyces cerevisiae. Genetics 163(4):1287–1298. https://doi.org/10.1093/genetics/163.4.1287
Kema GH, Yu D, Rijkenberg FH, Shaw MW, Baayen RP (1996) Histology of the pathogenesis of Mycosphaerella graminicola in wheat. Phytopathology 86(7):777–786. https://doi.org/10.1094/phyto-86-777
Acknowledgements
Z. tritici IPO323 strain and pCHYG-JK plasmid were kindly provided by Dr. Jason Rudd from Rothamsted Research Institute.
Funding
This project was supported by TÜBİTAK (project number 114O083) under COST action “Pathogen-informed strategies for sustainable broad-spectrum crop resistance”.
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ZM performed knockout experiments and statistical analysis, and wrote the manuscript, FÖ conceptualized and established the methodology. MA Conceptualized and supervised the experiments and reviewed the manuscript.
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Mustafa, Z., Ölmez, F. & Akkaya, M. Inactivation of a candidate effector gene of Zymoseptoria tritici affects its sporulation. Mol Biol Rep 49, 11563–11571 (2022). https://doi.org/10.1007/s11033-022-07879-z
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DOI: https://doi.org/10.1007/s11033-022-07879-z