Trichoderma reesei mycoparasitism against Pythium ultimum is coordinated by G-alpha protein GNA1 signaling
Carregando...
Data
2014
Título da Revista
ISSN da Revista
Título de Volume
Editor
Resumo
Trichoderma reesei (Hypocrea jecorina) is widely explored in industry and its potential for using in agriculture as
a biocontrol agent against phytophatogenic fungi has just began to be investigated. We have investigated the
involvement of G proteins during mycoparasitism against plant pathogens. Here we described the role of GNA1, a
G-alpha protein that belongs to α i group in Cell Wall Degrading Enzymes (CWDEs) production by T. reesei during
antagonism against Pythium ultimum. For that, two mutants were used: Δgna1 and gna1QL (=constitutively activated
version of GNA1). The gna1QL mutant of T. reesei, like the parental TU-6, inhibited the growth of P. ultimum in plate
confrontation assay and grew faster than the parental TU-6 while the Δgna1 did not grow over P. ultimum. Scanning
electron microscopy showed that the gna1QL mutant promoted more morphological alterations of P. ultimum cell
wall than the parental TU-6 while the Δgna1 caused no effects. The mutant Δgna1 showed less CWDEs activity
than gna1QL and TU-6 during in vitro cultivations. The gna1QL mutant showed a better performance in production
of CWDEs such as endochitinase, N-Acetyl-β-D-glucosaminidase (NAGase), lipase and acid phosphatase, after
72 hours of incubation. However, the parental TU-6 showed higher cellulase activity than gna1QL and Δgna1. The
intracellular content of cAMP in the strains after 72 hours of incubation in the presence of P. ultimum cell wall was:
gna1QL (79.85 ± 12), Δgna1 (268.65 ± 8.5) and TU-6 (109.70 ± 9.2) pmol/mg protein. RT-qPCR results showed a
low level of transcripts of mycoparasitism-specific genes in Δgna1 strain. We therefore suggest that the production
of some CWDEs during mycoparasitism by T. reesei against P. ultimum can be mediated by GNA1 activity or cAMP
levels.
Descrição
Palavras-chave
Degrading enzymes, Trichoderma reesei, G-protein, Mycoparasitism
Citação
MONTEIRO, Valdirene Neves; STEINDORF, Andrei Stecca; ALMEIDA, Fausto Bruno dos Reis; LOPES, Fabyano Alvares Cardoso; ULHOA, Cirano José; FELIX, Carlos Roberto; SILVA, Roberto Nascimento. Trichoderma reesei mycoparasitism against Pythium ultimum is coordinated by G-alpha protein GNA1 signaling. Journal of Microbial & Biochemical Technology, Traian, v. 7, n. 1, p. 1-7, 2015.