Relation of Temperature to Germination of Conidia and Appressorium Formation in Colletotrichum lagenarium

Mycologia ◽  
1969 ◽  
Vol 61 (2) ◽  
pp. 382 ◽  
Author(s):  
Norio Ishida ◽  
Shigeyasu Akai
Keyword(s):  
Appressorium Formation ◽  
Colletotrichum Lagenarium

Effects of temperature and antibiotics on appressorium formation in spores of Colletotrichum lagenarium

1977 ◽  
Vol 23 (5) ◽  
pp. 626-629 ◽  
Author(s):  
Machiko Tani ◽  
Norio Ishida ◽  
Iwao Furusawa
Keyword(s):  
Spore Germination ◽  
Germ Tube ◽  
Temperature Treatment ◽  
Appressorium Formation ◽  
Colletotrichum Lagenarium ◽  
Effects Of Temperature ◽  
Blasticidin S

Effects of temperature (32 °C), cycloheximide, and blasticidin-S on spore germination and appressorium formation of Colletotrichum lagenarium were investigated. Temperature treatment at 32 °C, given just before the emergence of the germ tube 4 h after incubation at 24 °C, significantly inhibited appressorium formation. Cycloheximide (1 ppm) or blasticidin-S (7 ppm) appeared to have reversed the effect of 32 °C treatment by producing appressoria in 30% of the germinated spores.

scholarly journals Protein Synthesis during Germination and Appressorium Formation of Colletotrichum lagenarium Spores

Microbiology ◽  
1981 ◽  
Vol 124 (1) ◽  
pp. 61-69 ◽  
Author(s):  
K. SUZUKI ◽  
I. FURUSAWA ◽  
N. ISHIDA ◽  
M. YAMAMOTO
Keyword(s):  
Protein Synthesis ◽  
Appressorium Formation ◽  
Colletotrichum Lagenarium

scholarly journals The Colletotrichum lagenarium Ste12-Like Gene CST1 Is Essential for Appressorium Penetration

2003 ◽  
Vol 16 (4) ◽  
pp. 315-325 ◽  
Author(s):  
Gento Tsuji ◽  
Satoshi Fujii ◽  
Seiji Tsuge ◽  
Tomonori Shiraishi ◽  
Yasuyuki Kubo
Keyword(s):  
Map Kinase ◽  
Lipid Droplets ◽  
Map Kinases ◽  
Cellulose Membrane ◽  
Appressorium Formation ◽  
Colletotrichum Lagenarium ◽  
Protein Map ◽  
Mitogen Activated Protein ◽  
Map Kinase Pathway ◽  
Kinase Pathway

Colletotrichum lagenarium is the causal agent of anthracnose of cucumber. This fungus produces a darkly melanized infection structure, appressoria, to penetrate the host leaves. The C. lagenarium CMK1 gene, a homologue of the Saccharomyces cerevisiae FUS3/KSS1 mitogen-activated protein (MAP) kinase genes, was shown to regulate conidial germination, appressorium formation, and invasive growth. In S. cerevisiae, Ste12p is known to be a transcriptional factor downstream of Fus3p/Kss1p MAP kinases. To evaluate the CMK1 MAP kinase pathway, we isolated the Ste12 homologue CST1 gene from C. lagenarium and characterized. The cst1Δ strains were nonpathogenic on intact host leaves, but could form lesions when inoculated on wounded leaves. Conidia of the cst1Δ strains could germinate and form melanized appressoria on both host leaf surface and artificial cellulose membrane, but could not produce infectious hyphae from appressoria, suggesting that CST1 is essential for appressorium penetration in C. lagenarium. In addition, matured appressoria of the cst1Δ strains contained an extremely low level of lipid droplets compared with that of the wild-type strain. Lipid droplets were abundant in conidia of the cst1Δ strains, but rapidly disappeared during appressorium formation. This misscheduled lipid degradation might be related to the failure of appressorium penetration in the cst1Δ strain.

Construction of an equalized cDNA library fromColletotrichum lagenariumand its application to the isolation of differentially expressed genes

2000 ◽  
Vol 46 (2) ◽  
pp. 150-158 ◽  
Author(s):  
Atsuko Inagaki ◽  
Yoshitaka Takano ◽  
Yasuyuki Kubo ◽  
Kazuyuki Mise ◽  
Iwao Furusawa
Keyword(s):  
Amino Acid ◽  
Cdna Library ◽  
Differentially Expressed Genes ◽  
Kinetic Method ◽  
Differential Screening ◽  
Differentially Expressed ◽  
Phytopathogenic Fungus ◽  
Cdna Clones ◽  
Appressorium Formation ◽  
Colletotrichum Lagenarium

To establish an efficient screening system for differentially expressed genes of a phytopathogenic fungus Colletotrichum lagenarium, we constructed an equalized (normalized) cDNA library from C. lagenarium and used this library for differential screening. For the isolation of genes involved in infection-related developments of conidia, conidia undergoing appressorium differentiation were selected as the source of materials for construction of the cDNA library. The equalization of cDNA was performed twice using a kinetic method, and the products were cloned into a plasmid vector. Colony hybridization with nine probes of different abundance showed a reduction in abundance variation from at least 276-fold in the original library to 10-fold in the equalized cDNA library, which demonstrated that the cDNA was successfully equalized. By differential hybridization of 1900 cDNA clones in the equalized cDNA library and RNA blot analysis of candidate clones, we identified 11 independent cDNA clones, designated CAD1 through CAD11, that were expressed in appressorium-differentiating conidia, but not in vegetative mycelia. The transcripts of CAD1 and CAD2 hardly accumulated in preincubated conidia, whereas those of CAD3 and CAD4 accumulated highly and slightly, respectively. The amount of the four CAD transcripts increased at the early stage of the appressorium formation process. Sequence analysis of CAD1 revealed that CAD1 would encode for 101 amino acid polypeptides, which showed homology to metallothioneins. Deduced amino acid sequence of CAD2 would encode 278 amino acid polypeptides, and showed high homology to genes in aflatoxin, and sterigmatocystin gene clusters of Aspergillus parasiticus and A. nidulans, respectively. Key words: equalized cDNA library, differential screening, Colletotrichum lagenarium, appressorium formation, CAD genes.

scholarly journals Kelch Repeat Protein Clakel2p and Calcium Signaling Control Appressorium Development in Colletotrichum lagenarium

2007 ◽  
Vol 7 (1) ◽  
pp. 102-111 ◽  
Author(s):  
Ayumu Sakaguchi ◽  
Toshihiko Miyaji ◽  
Gento Tsuji ◽  
Yasuyuki Kubo
Keyword(s):  
Microtubule Assembly ◽  
Calcium Signal ◽  
Cellular Polarity ◽  
Appressorium Formation ◽  
Cellular Functions ◽  
Colletotrichum Lagenarium ◽  
Cucumber Cotyledon ◽  
Penetration Ability ◽  
Cellulose Membranes ◽  
Appressorium Development

ABSTRACT Kelch repeat proteins are important mediators of fundamental cellular functions and are found in diverse organisms. However, the roles of these proteins in filamentous fungi have not been characterized. We isolated a kelch repeat-encoding gene of Colletotrichum lagenarium ClaKEL2, a Schizosaccharomyces pombe tea1 homologue. Analysis of the clakel2 mutant indicated that ClaKEL2 was required for the establishment of cellular polarity essential for proper morphogenesis of appressoria and that there is a plant signal-specific bypass pathway for appressorium development which circumvents ClaKEL2 function. Clakel2p was localized in the polarized region of growing hyphae and germ tubes, and the localization was disturbed by a microtubule assembly blocker. The clakel2 mutants formed abnormal appressoria, and those appressoria were defective in penetration hypha development into cellulose membranes, an artificial model substrate for fungal infection. Surprisingly, the clakel2 mutants formed normal appressoria on the host plant and retained penetration ability. Normal appressorium formation on the artificial substrate by the clakel2 mutants was restored when cells were incubated in the presence of CaCl2 or exudates from cucumber cotyledon. Furthermore, calcium channel modulators inhibited restoration of normal appressorium formation. These results suggest that there could be a bypass pathway that transduces a plant-derived signal for appressorium development independent of ClaKEL2 and that a calcium signal is involved in this transduction pathway.

scholarly journals The Mitogen-Activated Protein Kinase Gene MAF1 Is Essential for the Early Differentiation Phase of Appressorium Formation in Colletotrichum lagenarium

2002 ◽  
Vol 15 (12) ◽  
pp. 1268-1276 ◽  
Author(s):  
Kaihei Kojima ◽  
Taisei Kikuchi ◽  
Yoshitaka Takano ◽  
Eriko Oshiro ◽  
Tetsuro Okuno
Keyword(s):  
Protein Kinase ◽  
Mitogen Activated Protein Kinase ◽  
Nutrient Agar ◽  
Wild Type ◽  
Appressorium Formation ◽  
Colletotrichum Lagenarium ◽  
Early Differentiation ◽  
Mitogen Activated Protein ◽  
Germ Tubes ◽  
Mapk Gene

Colletotrichum lagenarium, the causal agent of cucumber anthracnose, invades host plants by forming a specialized infection structure called an appressorium. In this fungus, the mitogen-activated protein kinase (MAPK) gene CMK1 is involved in several steps of the infection process, including appressorium formation. In this study, the goal was to investigate roles of other MAPKs in C. lagenarium. The MAPK gene MAF1, related to Saccharomyces cerevisiae MPK1 and Magnaporthe grisea MPS1, was isolated and functionally characterized. The maf1 gene replacement mutants grew normally, but there was a significant reduction in conidiation and fungal pathogenicity. The M. grisea mps1 mutant forms appressoria, but conidia of the C. lagenarium maf1 mutants produced elongated germ tubes without appressoria on both host plant and glass, on which the wild type forms appressoria, suggesting that MAF1 has an essential role in appressorium formation on inductive surfaces. On a nutrient agar, wild-type conidia produced elongated germ tubes without appressoria. The morphological phenotype of the wild type on the nutrient agar was similar to that of the maf1 mutants on inductive surfaces, suggesting repression of the MAF1-mediated appressorium differentiation on the nutrient agar. The cmk1 mutants failed to form normal appressoria but produced swollen, appressorium-like structures on inductive surfaces, which is morphologically different from the maf1 mutants. These findings suggest that MAF1 is required for the early differentiation phase of appressorium formation, whereas CMK1 is involved in the maturation of appressoria.

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