Abstract
Preinfection development in Colletotrichum spp. exhibits three morphologies (conidia, germ tubes, and appressoria) and is directed by a complex interplay of environmental signals. Germ tube morphogenesis for Colletotrichum trifolii and the related fungus Colletotrichum gloeosporioides f. sp. aeschynomene was shown to be partially dependent on a balance between self-germination inhibitors and environmental nutrients or cutin. The degree of responsiveness to these environmental signals was strikingly different between the two fungal species. A solid contact surface stimulated germ tube morphogenesis and was the only apparent requirement for appressorium morphogenesis in both fungi. A population of C. trifolii conidia was incubated on a solid surface in the presence of cutin to stimulate nearly synchronous preinfection morphogenesis for gene expression analysis. RNA analysis of signal-transducing genes from C. trifolii, including genes for a serine-threonine kinase (TB3), calmodulin, and protein kinase C, showed that maximum transcription of all three genes occurred in conidia prior to or during germ tube morphogenesis. Transcription of melanin biosynthetic genes THR1 and SCD1 (Y. Kubo, Y. Takano, and I. Furusawa, Colletotrichum Newsl. II:5-10, 1996; N. S. Perpetua, Y. Kubo, N. Yasuda, Y. Takano, and I. Furusawa, Mol. Plant-Microbe Interact. 9:323-329, 1996) was highest prior to and during appressorium morphogenesis.
Full Text
The Full Text of this article is available as a PDF (233.5 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Beckerman J. L., Ebbole D. J. MPG1, a gene encoding a fungal hydrophobin of Magnaporthe grisea, is involved in surface recognition. Mol Plant Microbe Interact. 1996 Aug;9(6):450–456. doi: 10.1094/mpmi-9-0450. [DOI] [PubMed] [Google Scholar]
- Buhr T. L., Dickman M. B. Isolation, characterization, and expression of a second beta-tubulin-encoding gene from Colletotrichum gloeosporioides f. sp. aeschynomene. Appl Environ Microbiol. 1994 Nov;60(11):4155–4159. doi: 10.1128/aem.60.11.4155-4159.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Buhr T. L., Oved S., Truesdell G. M., Huang C., Yarden O., Dickman M. B. A kinase-encoding gene from Colletotrichum trifolii complements a colonial growth mutant of Neurospora crassa. Mol Gen Genet. 1996 Jul 19;251(5):565–572. doi: 10.1007/BF02173646. [DOI] [PubMed] [Google Scholar]
- Chomczynski P., Sacchi N. Single-step method of RNA isolation by acid guanidinium thiocyanate-phenol-chloroform extraction. Anal Biochem. 1987 Apr;162(1):156–159. doi: 10.1006/abio.1987.9999. [DOI] [PubMed] [Google Scholar]
- Feinberg A. P., Vogelstein B. A technique for radiolabeling DNA restriction endonuclease fragments to high specific activity. Anal Biochem. 1983 Jul 1;132(1):6–13. doi: 10.1016/0003-2697(83)90418-9. [DOI] [PubMed] [Google Scholar]
- Flaishman M. A., Kolattukudy P. E. Timing of fungal invasion using host's ripening hormone as a signal. Proc Natl Acad Sci U S A. 1994 Jul 5;91(14):6579–6583. doi: 10.1073/pnas.91.14.6579. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Free S. J., Rice P. W., Metzenberg R. L. Arrangement of the genes coding for ribosomal ribonucleic acids in Neurospora crassa. J Bacteriol. 1979 Mar;137(3):1219–1226. doi: 10.1128/jb.137.3.1219-1226.1979. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hoch H. C., Staples R. C., Whitehead B., Comeau J., Wolf E. D. Signaling for growth orientation and cell differentiation by surface topography in uromyces. Science. 1987 Mar 27;235(4796):1659–1662. doi: 10.1126/science.235.4796.1659. [DOI] [PubMed] [Google Scholar]
- Newton A. C. Protein kinase C: structure, function, and regulation. J Biol Chem. 1995 Dec 1;270(48):28495–28498. doi: 10.1074/jbc.270.48.28495. [DOI] [PubMed] [Google Scholar]
- Perpetua N. S., Kubo Y., Yasuda N., Takano Y., Furusawa I. Cloning and characterization of a melanin biosynthetic THR1 reductase gene essential for appressorial penetration of Colletotrichum lagenarium. Mol Plant Microbe Interact. 1996 Jul;9(5):323–329. doi: 10.1094/mpmi-9-0323. [DOI] [PubMed] [Google Scholar]
- Podila G. K., Rogers L. M., Kolattukudy P. E. Chemical Signals from Avocado Surface Wax Trigger Germination and Appressorium Formation in Colletotrichum gloeosporioides. Plant Physiol. 1993 Sep;103(1):267–272. doi: 10.1104/pp.103.1.267. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rasmussen C. D., Means R. L., Lu K. P., May G. S., Means A. R. Characterization and expression of the unique calmodulin gene of Aspergillus nidulans. J Biol Chem. 1990 Aug 15;265(23):13767–13775. [PubMed] [Google Scholar]