scholarly journals Cloning of a gene expressed during appressorium formation by Colletotrichum gloeosporioides and a marked decrease in virulence by disruption of this gene.

1995 ◽  
Vol 7 (2) ◽  
pp. 183-193 ◽  
Author(s):  
C S Hwang ◽  
M A Flaishman ◽  
P E Kolattukudy
Keyword(s):  
Colletotrichum Gloeosporioides ◽  
Marked Decrease ◽  
Appressorium Formation

scholarly journals Calcium/Calmodulin-Dependent Signaling for Prepenetration Development in Colletotrichum gloeosporioides

2003 ◽  
Vol 93 (1) ◽  
pp. 82-87 ◽  
Author(s):  
Kwang-Heum Uhm ◽  
Il-Pyung Ahn ◽  
Soonok Kim ◽  
Yong-Hwan Lee
Keyword(s):  
Colletotrichum Gloeosporioides ◽  
Calcium Ionophore ◽  
Conidial Germination ◽  
Red Pepper ◽  
Ionophore A23187 ◽  
Channel Blockers ◽  
Signaling System ◽  
Calmodulin Antagonists ◽  
Appressorium Formation ◽  
Calcium Calmodulin Dependent

Colletotrichum gloeosporioides forms a specialized infection structure, an appressorium, for host infection. Contacting hard surface induces appressorium formation in C. gloeosporioides, whereas hydrophobicity of the contact surface does not affect this infection-related differentiation. To determine if the calcium/calmodulin-dependent signaling system is involved in prepenetration morphogenesis in C. gloeosporioides pathogenic on red pepper, effects of calcium chelator (EGTA), phospholipase C inhibitor (neomycin), intracellular calcium modulators (TMB-8 and methoxy verampamil), and calmodulin antagonists (chloroproma-zine, phenoxy benzamine, and W-7) were tested on conidial germination and appressorium formation. Exogenous addition of Ca2+, regardless of concentration, augmented conidial germination, while appressorial differentiation decreased at higher concentrations. Inhibition of appressorium formation by EGTA was partly restored by the addition of calcium ionophore A23187 or CaCl2. Calcium channel blockers and calmodulin antagonists specifically reduced appressorium formation at micromolar levels. These results suggest that biochemical processes controlled by the calcium/calmodulin signaling system are involved in the induction of prepenetration morphogenesis in C. gloeosporioides pathogenic on red pepper.

scholarly journals CgNPG1 as a Novel Pathogenic Gene of Colletotrichum gloeosporioides From Hevea brasiliensis in Mycelial Growth, Conidiation, and the Invasive Structures Development

2021 ◽  
Vol 12 ◽  
Author(s):  
Chen Liang ◽  
Bei Zhang ◽  
Yun Zhou ◽  
Hongyan Yin ◽  
Bang An ◽  
...  
Keyword(s):  
Natural Rubber ◽  
Hevea Brasiliensis ◽  
Mycelial Growth ◽  
Colletotrichum Gloeosporioides ◽  
Germination Rate ◽  
Formation Rate ◽  
Rubber Tree ◽  
Appressorium Formation ◽  
Conidia Germination ◽  
Pathogenic Gene

The rubber tree (Hevea brasiliensis) is a tropical perennial crop for the primary source of natural rubber. Colletotrichum gloeosporioides from Hevea brasiliensis (C. gloeosporioides Hb) and Colletotrichum acutatum from Hevea brasiliensis (C. acutatum Hb) are the causal agents of rubber tree anthracnose and lead to serious loss of natural rubber production. Inoculation tests showed that C. gloeosporioides Hb possessed higher pathogenicity than C. acutatum Hb to the rubber tree. Genomic analysis revealed that an unknown gene, named CgNPG1 (a Novel Pathogenic Gene 1), was presented in the genome of C. gloeosporioides Hb but not identified in C. acutatum Hb. CgNPG1 was predicted to encode a small secretory protein without any conserved domain. To investigate the functions of CgNPG1 in C. gloeosporioides Hb and in C. acutatum Hb, the gene deletion and overexpression mutants were generated. The phenotype analysis showed that deletion of CgNPG1 led to changed conidia morphology, decreased mycelial growth, conidiation, conidia germination rate, appressorium formation rate, and pathogenicity of C. gloeosporioides Hb to the rubber tree. Meanwhile, heterogeneous expression of CgNPG1 in C. acutatum Hb significantly changed the conidia morphology and improved the mycelial growth rate, conidiation, conidia germination rate, appressorium formation rate, and the pathogenicity of C. acutatum Hb to the rubber tree. Consistently, CgNPG1 increased the expression level of CaCRZ1 and CaCMK1 in C. acutatum Hb. These data suggested that CgNPG1 contributed to mycelial growth, conidiation, the development of invasive structures, and the pathogenicity of Colletotrichum to the rubber tree, which might be related to the modulation of CaCRZ1 and mitogen-activated protein kinase CMK1. Our results provided new insight into CgNPG1 in regulating growth and pathogenicity of the Colletotrichum spp.

scholarly journals The Analysis of Fruit Protection Mechanisms Provided by Reduced-Pathogenicity Mutants of Colletotrichum gloeosporioides Obtained by Restriction Enzyme Mediated Integration

2002 ◽  
Vol 92 (11) ◽  
pp. 1196-1201 ◽  
Author(s):  
N. Yakoby ◽  
D. Beno-Moualem ◽  
I. Kobiler ◽  
D. Prusky
Keyword(s):  
Reactive Oxygen Species ◽  
Atpase Activity ◽  
Restriction Enzyme ◽  
Phenylalanine Ammonia Lyase ◽  
Colletotrichum Gloeosporioides ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Appressorium Formation ◽  
Avocado Fruit ◽  
Signaling Events

Colletotrichum gloeosporioides is an important postharvest pathogen that attacks ripe avocado fruit. Two reduced-pathogenicity mutants, Cg-M-142 and Cg-M-1150, previously obtained by restriction enzyme mediated integration, were used for the sequential analysis of the induction of biocontrol in avocado fruit. Plant biochemical indicators, such as H+-ATPase activity and levels of reactive oxygen species, phenylalanine ammonia lyase, epicatechin, and an antifungal diene, were investigated. The main difference between Cg-M-142 and Cg-M-1150 was the lack of appressorium formation by the latter. Preinoculation of avocado fruit with Cg-M-142 enhanced H+-ATPase activity and the production of reactive oxygen species. These early signaling events were followed by higher phenylalanine ammonia lyase activity and higher levels of epicatechin and the antifungal diene, and decay was delayed. Unlike Cg-M-142, Cg-M-1150 did not activate early signaling events related to fruit resistance. We suggest that the initiation of early signaling events affecting fruit resistance is determined by the capability of the pathogen to interact with the fruit during appressorium formation. Furthermore, the intensity of the fruit defense response determines the level of resistance during fruit storage.

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