Melanin Is Not Required for Turgor Generation but Enhances Cell-Wall Rigidity in Appressoria of the Corn Pathogen Colletotrichum graminicola
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The ascomycete and causative agent of maize anthracnose and stem rot, Colletotrichum graminicola, differentiates melanized infection cells called appressoria that are indispensable for breaching the plant cell wall. High concentrations of osmolytes accumulate within the appressorium, and the internal turgor pressure of up to 5.4 MPa provides sufficient force to penetrate the leaf epidermis directly. In order to assess the function of melanin in C. graminicola appressoria, we identified and characterized the polyketide synthase 1 (CgPKS1) gene which displayed high similarity to fungal polyketide synthases (PKS) involved in synthesis of 1,3,6,8-tetrahydronaphthalene, the first intermediate in melanin biosynthesis. Cgpks1 albino mutants created by targeted gene disruption were unable to penetrate intact leaves and ruptured frequently but, surprisingly, were able to penetrate ultrathin polytetrafluoroethylene membranes mimicking the plant surface. Nonmelanized Cgpks1 appressoria were sensitive to externally applied cell-wall-degrading enzymes whereas melanized appressoria were not affected. Expression studies using a truncated CgPKS1 fused to green fluorescent protein revealed fluorescence in immature appressoria and in setae, which is in agreement with transcript data obtained by RNA-Seq and quantitative polymerase chain reaction. Unexpectedly, surface scans of mutant and wild-type appressoria revealed considerable differences in cell-wall morphology. Melanization of appressoria is indispensable for successful infection of intact leaves. However, cell collapse experiments and analysis of the appressorial osmolyte content by Mach-Zehnder interferometry convincingly showed that melanin is not required for solute accumulation and turgor generation, thus questioning the role of melanin as a barrier for osmolytes in appressoria of C. graminicola.
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In Colletotrichum graminicola, appressorial melanization is critical for leaf infection, but melanin is not required for solute accumulation or turgor generation.
“In C. graminicola, app yielded 296 mutants with no significant alterationressorial melanization is critical for leaf infection. Notably, melanin is not required for solute accumulation or turgor generation.”
From Fungal Melanin in Plant Pathogens: Complex Biosynthesis Pathways and Diverse Biological Functions (2025) · cites this paper as [62]
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Paula, S., Volkov, A. G., Van Hoek, A. N., Haines, T. H., & Deamer, D. W. (1996) · Biophysical Journal · doi:10.1016/s0006-3495(96)79575-9 · Cited by 578 · cited 1× · see citing works
“Determination of diffusion coefficients of hydrated molecules such as urea and glycerol showed that only very small amounts of these solutes permeate through artificial phospholipid bilayers (Paula et al. 1996).”
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Research works printed but not linked: 5
- Brown, T. 1999. Southern blotting. Pages 2.9.1-2.9.15 in: Current Proto- cols in Molecular Biology. F. M. Ausubel, R. Brent, R. E. Kingston, D. D. Moore, J. G. Seidman, J. A. Smith, and K. Struhl, eds. John Wiley & Sons, New York. Butler, M. J., and Day, A. W. 1999. Fungal melanins: A review. Can. J. Microbiol. 44:1115-1136.
- Howard, R. J., Ferrari, M. A., Roach, D. H., and Money, N. P. 1991. Pene- tration of hard substrates by a fungus employing enormous turgor pres- sures. Proc. Natl. Acad. Sci. U.S.A. 88:11281-11284.
- Kubo Y., and Furusawa I. 1991. Melanin biosynthesis: Prerequisite for successful invasion of the plant host by appressoria of Colletotrichum and Pyricularia. Pages 205-218 in: The Fungal Spore and Disease Initiation in Plants and Animals. G. T. Cole, and H. C. Hoch, eds. Plenum Publishing, New York.
- Loehrer, M., Botterweck, J., Jahnke, J., Mahlmann, D. M., Gaetgens, J., Oldiges, M., Horbach, R., Deising, H. B., and Schaffrath, U. In vivo assessment of the invasive force exerted by the Asian soybean rust fun- gus by resurrection of double-beam interferometry. New Phytol. In press.
- Yin, J., Straight, P. D., McLoughlin, S. M., Zhou, Z., Lin, A. J., Golan, D. E., Kelleher, N. L., Kolter, R., and Walsh, C. T. 2005. Genetically encoded short peptide tag for versatile protein labeling by Sfp phosphopantetheinyl transferase. Proc. Natl. Acad. Sci. U.S.A. 102:15815-15820.
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Fungal Melanin in Plant Pathogens: Complex Biosynthesis Pathways and Diverse Biological Functions
Jia, H., Liu, N., Zhang, L., Li, P., Meng, Y., Yuan, W., Li, H., Tantai, D., Qu, Q., Cao, Z., et al. (2025) · Plants · doi:10.3390/plants14142121 · Cited by 18 · see citing works
- Authors
- Ludwig, N., Löhrer, M., Hempel, M., Mathea, S., Schliebner, I., Menzel, M., Kiesow, A., Schaffrath, U., Deising, H. B., & Horbach, R.
- Affiliations
- Martin Luther University Halle-Wittenberg (DE)
- Max Planck Research Unit for Enzymology of Protein Folding (DE)
- RWTH Aachen University (DE)
- Fraunhofer Institute for Mechanics of Materials (DE)
- Venue
- Molecular Plant-Microbe Interactions®
- Publisher
- Scientific Societies
- Published
- 2014-04
- Volume
- 27
- Issue
- 4
- Pages
- 315-327
- ISSN
- 0894-0282 (ISSN-L)
- 1943-7706
- OpenAlex
- W2069878363
- Cited by
- 95
- References
- 1
- Citations by year
- 2026: 5 · 2025: 5 · 2024: 3 · 2023: 6 · 2022: 22 · 2021: 7 · 2020: 11 · 2019: 4 · 2018: 5 · 2017: 7 · 2016: 11 · 2015: 5 · 2014: 4
- FWCI
- 3.07
- Type
- journal article
- Language
- en
- Open access
- bronze
- doi.org
- Locations
- Molecular Plant-Microbe Interactions (publishedVersion)
- PubMed (publishedVersion)
- DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion)
- Fraunhofer-Publica (Fraunhofer-Gesellschaft) (submittedVersion)
- RWTH Publications (RWTH Aachen) (submittedVersion)
- Funders
- Deutsche Forschungsgemeinschaft
- School of Life and Environmental Sciences, Deakin University
- Topics
- Life Sciences › Biochemistry, Genetics and Molecular Biology › Cell Biology › Plant Pathogens and Fungal Diseases
- Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Fungal and yeast genetics research
- Life Sciences › Agricultural and Biological Sciences › Plant Science › Plant Disease Resistance and Genetics
- Keywords
- melanin, appressoria, Colletotrichum graminicola, turgor pressure, osmolytes, cell wall rigidity, polyketide synthase, melanogenesis, maize anthracnose, cell wall degrading enzymes, fungal pathogenesis
- MeSH terms
- Cell Wall, Zea mays, DNA, Fungal, Melanins, Molecular Sequence Data, Plant Diseases, Gene Expression Regulation, Fungal, Microscopy, Atomic Force, Colletotrichum
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