Interspecific interactions with Trichoderma longibrachiatum induce Pleurotus ostreatus defence reactions based on the production of laccase isozymes

Abstract

Laccases are phenoloxidases involved in aromatic compound transformation but also in stress response towards antagonist species such as Trichoderma sp. In this study intracellular isoforms of laccases produced by Pleurotus ostreatus in liquid cultures with or without Trichoderma longibrachiatum showed five isoforms with various intensities depending on the culture conditions suggesting a basal expression of these enzymes, which can be induced by interspecific interactions. A first attempt to analyse the induction of P. ostreatus laccase-gene expression by a biotic factor was realized using semi-quantitative RT-PCR. We showed that the transcription of a laccase gene of P. ostreatus can be modified by a biotic stress such as T. longibrachiatum.

Correlation of nitric oxide produced by an inducible nitric oxide synthase-like protein with enhanced expression of the phenylpropanoid pathway in Inonotus obliquus cocultured with Phellinus morii

“…These interactions lead to a broad array of changes in physiology, biochemistry, and secondary metabolism of the fungi (Afri et al 2013). Notably, mycelial encounters are associated with increased accumulation of phenylpropanoid metabolites (Hiscox et al 2010;Korkina 2007) and defense gene expression (Velázquez-Cedeño et al 2007). In this study, we show that interspecific interaction between I. obliquus and P. morii enhances transcription of the gene coding for iNOSL and results in increased production of NO.…”

Changes in oxidative enzyme activity during interspecific mycelial interactions involving the white-rot fungus Trametes versicolor

“…However, at the IZ interpretation is difficult due to potential contribution from both interacting species, whereas the transcript levels were specific to T. versicolor. A lag between gene expression and enzyme activity is normal and has been reported in interacting cultures of P. ostreatus (Velázquez-Cedeño et al, 2007). Other discrepancies between expression and activity of laccase could be explained by rapid release of laccase from intracellular stores, thus not involving de novo transcription.…”

Evolution of Multicopper Oxidase Genes in Coprophilous and Non-Coprophilous Members of the Order Sordariales

“…Intercellular laccase activity has been identified in basidiomycetes and ascomycetes, and is proposed to be involved in the transformation of low molecular weight phenolic compounds [1]. Five intracellular laccase isoforms were previously shown to be produced by the basidiomycete Pleurotus ostreatus when co-cultivated with the ascomycete Trichoderma longibrachiatum, suggesting expression of these enzymes can be induced by interspecies interactions [42]. Thus, the fungi analyzed here may possess intracellular laccases induced under specific environmental conditions.…”