Fungal membrane responses induced by plant defensins and thionins.
J Biol Chem
; 271(25): 15018-25, 1996 Jun 21.
Article
em En
| MEDLINE
| ID: mdl-8663029
ABSTRACT
Treatment of hyphae of Neurospora crassa with antifungal plant defensins, i.e. Rs-AFP2 and Dm-AMP1 isolated from radish and dahlia seed, respectively, induced a rapid K+ efflux, Ca2+ uptake, and alkalinization of the incubation medium. The Rs-AFP2-induced alkalinization of the incubation medium could be inhibited with G-protein inhibitors. alpha-Hordothionin, an antifungal thionin from barley seed, caused a sustained increased Ca2+ uptake at subinhibitory concentrations but only a transient increased uptake at inhibitory concentrations. alpha-Hordothionin also caused increased K+ efflux and alkalinization of the medium, but these fluxes occurred more rapidly compared to those caused by plant defensins. Furthermore, alpha-hordothionin caused permeabilization of fungal hyphae to the non-metabolite alpha-aminoisobutyric acid and, in addition, altered the electrical properties of artificial lipid bilayers, consistently leading to rupture of the lipid bilayers. The plant defensins did not form ion-permeable pores in artificial membranes and did not exhibit substantial hyphal membrane permeabilization activity. Our results are consistent with the notion that thionins inhibit fungal growth as a result of direct protein-membrane interactions, whereas plant defensins might act via a different, possibly receptor-mediated, mechanism.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Plantas
/
Membrana Celular
/
Peptídeos Catiônicos Antimicrobianos
/
Fusarium
/
Antifúngicos
/
Neurospora crassa
Idioma:
En
Revista:
J Biol Chem
Ano de publicação:
1996
Tipo de documento:
Article
País de afiliação:
Bélgica