Molecular Signaling Pathways Involved in Appressorium Development by Magnaporthe Grisea

  • G. C. Fang
  • R. A. Dean


The infection process of phytopathogenetic fungi involves a series of continuous interactions between the pathogenic agents and their hosts. Plants are equipped with a variety of physical and chemical strategies to restrain fungal invasion, including a waxy cuticle layer, preformed antimicrobial compounds, induction of the hypersensitive reaction, pathogenesis-related proteins (PR proteins) and phytoalexin biosynthesis, as well as the establishment of systemic acquired resistance (SAR). To establish a successful infection, pathogenic fungi must first be able to penetrate the epidermis, which is coated with a waxy cuticle and thick cell wall. Some biotrophic fungi such as rusts and powdery mildews bypass the plant physical barrier by entering through stomata. However, many fungal pathogens produce appressoria as the primary weapon of direct penetration. Prior to the development of the appressorium, a variety of biological events occur, including secretion of certain adhesive compounds, hydrophobins or other proteins which assist in attaching the germ tubes to the host plant surface (Hamer et al., 1988; Talbot et al., 1993; Beckerman and Ebbole, 1996; Nicholson, 1996). Hydrolytic enzymes may be also secreted to soften and change the surface of the cuticle layer facilitating attachment and penetration (Deising et al., 1992; Pascholati et al., 1993). An infection peg emerges beneath the appressorium and, often driven by hydrostatic pressure, penetrates the epidermal cell. After entering, the infection hyphae continues to develop and ramifies through the plant tissue.


Adenylate Cyclase Germ Tube Turgor Pressure Appressorium Formation Rice Blast Fungus 
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  1. Baasiri, R. A., Lu, X, Rowley, P. S., Turner, G. E. and Borkovich, K. A. (1997) Overlapping functions for two G protein a subunits in Neurospora crassa, Genetics 147, 137–145.PubMedGoogle Scholar
  2. Banuett, F. and Herskowitz, I. (1994) Identification of Fuzz, a Ustilago maydis MEK/MAPKK homolog required for a-locus-dependent and -independent steps in the fungal life cycle, Genes and Development 8, 1367–1378.PubMedCrossRefGoogle Scholar
  3. Beckerman, J. L. and Ebbole, D. J. (1996) MPG1, a gene encoding a fungal hydrophobin of Magnaporthe grisea, is involved in surface recognition, Molecular Plant-Microbe Interactions 9, 450–456.PubMedCrossRefGoogle Scholar
  4. Bencina, M., Panneman,.H., Ruijter, G. J. G., Legisa, M. and Visser, J. (1997) Characterization and overexpression of the Aspergillus niger gene encoding the cAMP-dependent protein kinase catalytic subunit, Microbiology 143, 1211–1220.Google Scholar
  5. Bruno, K. S., Aramayo, R., Minke, R. F., Metzenberg, R. L. and Plamann, M. (1996) Loss of growth polarity and mislocalization of septa in a Neurospora mutant altered in the regulatory subunit of cAMPdependent protein kinase, The EMBO Journal 15, 5772–5782.PubMedGoogle Scholar
  6. Buhr, T. L. and Dickman, M. B. (1997) Gene expression analysis during conidial germ tube and appressorium development in Colletotrichum trifolii, Applied and Environmental Microbiology 63, 2378–2383.PubMedGoogle Scholar
  7. Chen, B., Gso, S., Choi, G. H. and Nuss, D. L. (1996) Extensive alteration of fungal gene transcripts accumulation and elevation of G-protein-regulated cAMP levels by a virulence-attenuation hypovirus, Proceedings of the National Academy of Sciences USA 93, 7999–8000.Google Scholar
  8. Choi, G. H., Chen, B. and Nuss, D. L. (1995) Virus-mediated or transgenic suppression of a G-protein alpha subunit and attenuation of fungal virulence, Proceedings of the National Academy of Sciences USA 92, 305–309.CrossRefGoogle Scholar
  9. Chumley, F. G. and Valent, B. (1990) Genetic analysis of melanin-deficient, nonpathogenic mutants of Magnaporthe grisea, Molecular Plant-Microbe Interactions 3, 135–143.CrossRefGoogle Scholar
  10. Deising, H., Nicholson, R. L., Haug, M., Howard, R. J. and Mendgen, K. (1992) Adhesion pad formation and the involvement of cutinase and esterases in the attachment of uredospores to the host cuticle, The Plant Ce11 4, 1101–1111.Google Scholar
  11. de Jong, J. C., McCormack, B. J., Smirnoff, N. and Talbot, N. J. (1997) Glycerol generates turgor in rice blast, Nature 389, 244–245.CrossRefGoogle Scholar
  12. De Virgilio, C., Simmen, U., Hottiger, T., Boller, T. and Wiemken, A. (1990) Heat shock induces enzymes of trehalose metabolism, trehalose accumulation, and thermotolerance in Schizosaccharomyces pombe, even in the presence of cycloheximide, The FEBS Letters 273, 107–110.CrossRefGoogle Scholar
  13. Gerber, H.-P., Seipel, K., Georgiev, O., Hofferer, M., Hug, M., Rusconi, S. and Schaffner, W. (1994) Transcriptional activation modulated by homopolymeric glutamine and proline stretches, Science 263, 808–811.PubMedCrossRefGoogle Scholar
  14. Gilbert, R. D., Johnson, A. M. and Dean, R. A. (1996) Chemical signals responsible for appressorium formation in the rice blast fungus Magnaporthe grisea, Physiological and Molecular Plant Pathology 48, 335–346.CrossRefGoogle Scholar
  15. Gill, G., Pascal, E., Tseng, Z. H. and Tjian, R. (1994) A glutamine-rich hydrophobic patch in transcription factor Sp1 contacts the dTAF11110 component of the Drosophila TFIID complex and mediates transcriptional activation, Proceedings of the National Academy of Sciences USA 91, 192–196.CrossRefGoogle Scholar
  16. Gold, S. E., Duncan, G. A., Barrett, K. J. and Kronstad, J. W. (1994) cAMP regulates morphogenesis in the fungal pathogen Ustilago maydis, Genes and Development 8, 2805–2816.Google Scholar
  17. Gold, S. E., Brogdon, S. M., Mayoraga, M. E. and Kronstad, J. W. (1997) The Ustilago maydis regulatory subunit of a cAMP-dependent protein kinase is required for gall formation in maize, The Plant Cell 9, 1585–1594.PubMedGoogle Scholar
  18. Hamer, J. E., Howard, R. J. Chumley, F. G. and Valent, B. (1988) A mechanism for surface attachment in spores of a plant pathogenic fungus, Science 239, 288–290Google Scholar
  19. Hegde, Y. and Kolattukudy, P. E. (1997) Cuticular waxes relieve self-inhibition of germination and appressorium formation by the conidia of Magnaporthe grisea, Physiological and Molecular Plant Pathology 51, 75–84.CrossRefGoogle Scholar
  20. Hicks, J. K., Yu, J,-H. Keller, N. P. and Adams, T. H. (1997) Aspergillus sporulation and mycotoxin production both require inactivation of the FadA GE protein-dependent signalling pathway, The EMBO Journal 16, 4916–4923.PubMedCrossRefGoogle Scholar
  21. Howard, R., J. and Ferrari, M. A. (1989) Role of melanin in appressorium function, Experimental Mycology 13, 403–418.CrossRefGoogle Scholar
  22. Howard, R. J., Ferrari„ M. A., Roach, D. H. and Money, N. P. (1991) Penetration of hard substrates by a fungus employing enormous turgor pressures,, Proceedings of the National Academy of Sciences USA 88, 11281–11284.CrossRefGoogle Scholar
  23. Hubbard, M. J., and Cohen, P. (1993) On target with a new mechanism for the regulation of protein phosphorylation, Trends in Biochemical Science 18, 172–177.CrossRefGoogle Scholar
  24. Jelitto, T. C., Page, H. A. and Read, N. D. (1994) Role of external signals in regulating the pre-penetration phase of infection by the rice blast fungus, Magnaporthe grisea, Planta 194, 471–477.CrossRefGoogle Scholar
  25. Karin, M. (1994) Signal transduction from the cell surface to the nucleus through the phosphorylation of transcription factors, Current Opinion in Cell Biology 6, 415–424.PubMedCrossRefGoogle Scholar
  26. Kimura, N. and Tsuge, T. (1993) Gene cluster involved in melanin biosynthesis of the filamentous fungus Alternaria alternata, Journal of Bacteriology 175, 4427–4435.PubMedGoogle Scholar
  27. Kore-eda, S., Murayama, T. and Uno, I. (1991) Isolation and characterization of the adenylate cyclase gene of Neurospora crassa, The Japanese Journal of Genetics 66, 317–334CrossRefGoogle Scholar
  28. Kubo, Y. and Furusawa, I. (1991) Melanin biosynthesis: prerequisite for successful invasion of the plant host by appressoria of Colletotrichum and Pyricularia, in G. T. Cole and H. C. Hoch (eds.), The Fungal Spore and Disease Initiation in Plants and Animals, Plenum Publishing Corp., New York, pp. 205–218.Google Scholar
  29. Kuspa, A. and Loomis, W. F. (1992) Tagging developmental genes in Dictyostelium by restriction enzyme-mediated integration of plasmid DNA,. Proceedings of the National Academy of Sciences USA 89, 8803–8807.CrossRefGoogle Scholar
  30. Lee, Y.-H. and Dean, R. A. (1993) cAMP regulates infection structure formation in the plant pathogenic fungus Magnaporthe grisea, The Plant Cell 5, 693–700.Google Scholar
  31. Lee, Y.-H. and Dean, R. A. (1994) Hydrophobicity of contact surface induces appressorium formation in Magnaporthe grisea, The FEMS Microbiology Letters 115, 71–76.CrossRefGoogle Scholar
  32. Liu, S. and Dean, R. A. (1997) G protein r subunit genes control growth, development, and pathogenicity of Magnaporthe grisea, Molecular Plant-Microbe Interactions 10, 1075–1086.PubMedCrossRefGoogle Scholar
  33. Loubradou, G., Begueret, J. and Turcq, B. (1996) An additional copy of the adenylate cyclase-encoding gene relieves developmental defects produced by a mutation in a vegetative incompatibility-controlling gene in Podospora anserina, Gene 170, 119–123.PubMedCrossRefGoogle Scholar
  34. Mitchell, T. K. and Dean, R. A. (1995) The cAMP-dependent protein kinase catalytic subunit is required for appressorium formation and pathogenesis by the rice blast pathogen Magnaporthe grisea, The Plant Cell 7, 1869–1878.PubMedGoogle Scholar
  35. Money, N. P. and Howard, R. J. (1996) Confirmation of a link between fungal pigmentation, turgor pressure, and pathogenicity using a new method of.turgor measurement, Fungal Genetics and Biology 20, 217–227.CrossRefGoogle Scholar
  36. Neer, E. J. (1995) Heterotrimeric G proteins: organizers of transmembrane signals, Cell 80, 249–257.PubMedCrossRefGoogle Scholar
  37. Neiman, A. M. (1993) Conservation and reiteration of a kinase cascade, Trends in Genetics 9, 390–394.PubMedCrossRefGoogle Scholar
  38. Nicholson, R. 1. (1996) Adhesion of fungal propagules, in M. Nicole and V. Gianinazi-Pearson (eds.), Histology, Ultrastructure and Molecular Cytology of Plant-Microorganism Interactions, Kluwer Academic Publishers, Amsterdam, pp. 117–134.Google Scholar
  39. Nishida, Y. M. and Gotoh, Y. (1993) The MAP kinase cascade is essential for diverse signal transduction pathways, Trends in Biological Science 18, 128–131.CrossRefGoogle Scholar
  40. Ou, S. H. (1985) Rice Diseases, 2nd ed. Commonwealth Mycological Institute, Surrey, UK.Google Scholar
  41. Pascholati, S. F., Deising, H., Leite, B., Anderson, D. and Nicholson, R. L. (1993) Cutinase and non-specific esterase activities in the conidial mucilage of Colletotrichum graminicola, Physiological and Molecular Plant Pathology 42, 37–51.CrossRefGoogle Scholar
  42. Perpetua, N. S., Kubo, Y., Yasuda, N., Takano, Y. and Furusawa, I. (1996) Cloning and characterization of a melanin biosynthetic THRI reductase gene essential for appressorial penetration of Colletotrichum lagenarium, Molecular Plant-Microbe Interactions 9, 323–329.PubMedCrossRefGoogle Scholar
  43. Rasmussen, J. B. and Hanau, R. M. (1989) Exogenous scytalone restores appressorial melanization and pathogenicity in albino mutants of Colletotrichum graminicola, Canadian Journal of Plant Pathology 11, 349–352.CrossRefGoogle Scholar
  44. Regenfelder, E., Spellig, T., Hartmann, A., Lauenstein, S., Bolker, M. and Kahmann, R. (1997) G proteins in Ustilago maydis: transmission of multiple signals? The EMBO Journal 16, 1934–1942.PubMedCrossRefGoogle Scholar
  45. Schiestl, R. H. and Petes, T. D. (1991) Integration of DNA fragment by illegitimate recombination in Saccharomyces cerevisiae, Proceedings of the National Academy of Sciences USA 88, 7585–7589.CrossRefGoogle Scholar
  46. Simon, M. I., Strathmann, M. P. and Gautam, N. (1991) Diversity of G proteins in signal transduction, Science 252, 802–808.PubMedCrossRefGoogle Scholar
  47. Talbot, N. J., Ebbole, D. J. and Hamer, J. E. (1993) Identification and characterization of MPG I, a gene involved in pathogenicity from the rice blast fungus Magnaporthe grisea, The Plant Cell 5, 1575–1590.PubMedGoogle Scholar
  48. Tanaka, M., Clouston, W. M. and Herr, W. (1994) The oct-2 glutamine-rich and proline-rich activation domains can synergize with each other or duplicates of themselves to activate transcription, Molecular and Cellular Biology 14, 6046–6055.PubMedCrossRefGoogle Scholar
  49. Teng, P. S. (1994) The epidemiological basis for blast management, in R. S. Zeiger, S. A. Leong, and P. S. Teng (eds.), Rice Blast Disease, CABI, Wallingford, pp. 409–434.Google Scholar
  50. Thines, E., Eilbert, F., Sterner, O. and Anke, H. (1997) Glisoprenin A, an inhibitor of the signal transduction pathway leading to appressorium formation in germinating conidia of Magnaporthe grisea on hydrophobic surfaces, The FEMS Microbiology Letters 151, 219–224.CrossRefGoogle Scholar
  51. Uchiyama, T., Ogasawara, N., Nanba, Y. and Ito, H. (1979) Conidial germination and appressorial formation of the plant pathogenic fungi on the coverglass or cellophane coated with various lipid components of plant leaf waxes, Agricultural and Biological Chemistry 43, 383–384.CrossRefGoogle Scholar
  52. Uno, I. and Ishikawa, T. (1973) Metabolism of adenosine 3’, 5’-cyclic monophosphate and induction of fruiting bodies in Coprinus macrorhizus, Journal of Bacteriology 11, 1249–1255.Google Scholar
  53. Uno, I., Matsumoto, K., Adachi, K. and Ishikawa, T. (1983) Genetic and biochemical evidence that trehalase is a substrate of cAMP-dependent protein kinase in yeast, Journal of Biological Chemistry 258, 1086710872.Google Scholar
  54. Walsh, D. A. and van Patten, S. M. (1994) Multiple pathway signal transduction by the cAMP-dependent protein kinase, The FASEB Journal 8, 1227–1236.Google Scholar
  55. Woloshuk, C. P., Sisler, H. D., Tokousbalides, M. C. and Dutky, S. R. (1980) Melanin biosynthesis in Pyricularia oryzae: site of tricyclazole inhibition and pathogenicity of melanin-deficient mutants. Pestical and Biochemical Physiology 14, 256–264.CrossRefGoogle Scholar
  56. Xu, J.-R. and Hamer, J. E. (1996) MAP kinase and cAMP signaling regulate infection structure formation and pathogenic growth in the rice blast fungus Magnaporthe grisea, Genes and Development 10, 2696–2706.PubMedCrossRefGoogle Scholar
  57. Xu, J.-R., Urban, M., Sweigerd, J. A. and Hamer, J. E. (1997) The cpkA gene of Magnaporthe grisea is essential for appressorial penetration, Molecular Plant-Microbe Interactions 10, 187–194.CrossRefGoogle Scholar
  58. Zhu, H., Whitehead, D. S., Lee, Y.-H. and Dean, R. A. (1996) Genetic analysis of development mutants and rapid chromosome mapping of APP I, a gene required for appressorium formation in Magnaporthe grisea, Molecular Plant-Microbe Interactions 9, 767–774.CrossRefGoogle Scholar
  59. Zhu, H., Choi, S., Johnston, A. K., Wing, R. A. and Dean, R. A. (1997) A large-insert (130 kb) bacterial artificial chromosome library of the rice blast fungus Magnaporthe grisea: genome analysis, contig assembly, and gene cloning, Fungal Genetics and Biology 21, 337–347.PubMedCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media Dordrecht 2001

Authors and Affiliations

  • G. C. Fang
    • 1
  • R. A. Dean
    • 1
  1. 1.Department of Plant Pathology and PhysiologyClemson UniversityClemsonUSA

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