title: Endochitinase CHI2 of the biocontrol fungus Metarhizium anisopliae affects its virulence toward the cotton stainer bug Dysdercus peruvianus.
abstract: Chitinases have been implicated in fungal cell wall remodeling and play a role in exogenous chitin degradation for nutrition and competition. Due to the diversity of these enzymes, assigning particular functions to each chitinase is still ongoing. The entomopathogenic fungus Metarhizium anisopliae produces several chitinases, and here, we evaluate whether endochitinase CHI2 is involved in the pathogenicity of this fungus. We constructed strains either overexpressing or lacking the CHI2 chitinase. These constructs were validated by Southern, Northern and Western blot analysis, and chitinase production. To access the effects of CHI2 chitinase in virulence, the cotton stainer bug Dysdercus peruvianus was used as a host. CHI2 overexpression constructs showed higher efficiency in host killing suggesting that the production of this chitinase by a constitutive promoter reduces the time necessary to kill the insect. More significantly, the knock out constructs showed decreased virulence to the insects as compared to the wild type strain. The lack of this single CHI2 chitinase diminished fungal infection efficiency, but not any other detectable trait, showing that the M. anisopliae family 18, subgroup B endochitinase CHI2 plays a role in insect infection.
authors: Programa de Pós-graduação em Biologia Celular e Molecular, Centro de Biotecnologia da Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9500, Bloco IV, Prédio 43-421, Bairro Agronomia, Porto Alegre, Rio Grande do Sul, CEP 91501-970, Brazil.
authors: Juliano Tomazzoni
authors: JT
authors: Boldo
authors: Angela
authors: A
authors: Junges
authors: Karina Bohrer
authors: KB
authors: do Amaral
authors: Charley Christian
authors: CC
authors: Staats
authors: Marilene Henning
authors: MH
authors: Vainstein
authors: Augusto
authors: A
authors: Schrank
mesh_terms: D000818:Animals; D001483:Base Sequence; D002688:Chitinases / Q000378:metabolism*; D017931:DNA Primers; D015151:Immunoblotting; D007313:Insecta / Q000382:microbiology*; D052981:Metarhizium / Q000201:enzymology / Q000472:pathogenicity*; D010572:Pest Control, Biological; D014774:Virulence
chemical_list: D017931:DNA Primers; D002688:Chitinases