Host-specific transcriptomic pattern of Trichoderma virens during interaction with maize or tomato roots

Abstract

BackgroundMembers of the fungal genus Trichoderma directly antagonize soil-borne fungal pathogens, and an increasing number of species are studied for their potential in biocontrol of plant pathogens in agriculture. Some species also colonize plant roots, promoting systemic resistance. The Trichoderma-root interaction is hosted by a wide range of plant species, including monocots and dicots.ResultsTo test the hypothesis that gene expression by the fungal partner in this beneficial interaction is modulated by the plant, Trichoderma virens was co-cultured with maize or tomato in a hydroponic system allowing interaction with the roots. The transcriptomes for T. virens alone were compared with fungus-inoculated tomato or maize roots by hybridization on microarrays of 11645 unique oligonucleotides designed from the predicted protein-coding gene models. Transcript levels of 210 genes were modulated by interaction with roots. Almost all were up-regulated. Glycoside hydrolases and transporters were highly represented among transcripts induced by co-culture with roots. Of the genes up-regulated on either or both host plants, 35 differed significantly in their expression levels between maize and tomato. Ten of these were expressed higher in the fungus in co-culture with tomato roots than with maize. Average transcript levels for these genes ranged from 1.9 fold higher on tomato than on maize to 60.9 fold for the most tomato-specific gene. The other 25 host-specific transcripts were expressed more strongly in co-culture with maize than with tomato. Average transcript levels for these genes were 2.5 to 196 fold higher on maize than on tomato.ConclusionsBased on the relevant role of Trichoderma virens as a biological control agent this study provides a better knowledge of its crosstalk with plants in a host-specific manner. The differentially expressed genes encode proteins belonging to several functional classes including enzymes, transporters and small secreted proteins. Among them, glycoside hydrolases and transporters are highlighted by their abundance and suggest an important factor in the metabolism of host cell walls during colonization of the outer root layers. Host-specific gene expression may contribute to the ability of T. virens to colonize the roots of a wide range of plant species.Electronic supplementary materialThe online version of this article (doi:10.1186/s12864-014-1208-3) contains supplementary material, which is available to authorized users.

Transcriptional reprogramming underpins enhanced plant growth promotion by the biocontrol fungus Trichoderma hamatum GD12 during antagonistic interactions with Sclerotinia sclerotiorum in soil

“…Thus, the biocontrol capabilities of different Trichoderma species appear to be heavily dependent on specific transcriptional reprogramming events during antagonistic interactions. For example, during PGP, T. virens cultured hydroponically with maize or tomato roots deployed both common and plant‐specific transcriptional programmes, with important roles implicated for glycosyl hydrolases and transporters (Moran‐Diez et al ., ). Plant–pathogen–hyperparasite interactions induce specific gene expression (Steindorff et al ., ), including the over‐representation of transporters and carbohydrate‐active enzymes, similar to those identified during T. virens PGP (Moran‐Diez et al ., ).…”

“…SSCRPs are predicted effectors hypothesized to play important roles in Trichoderma ‐mediated rhizosphere interactions (Moran‐Diez et al ., ), the induction of systemic resistance (Lamdan et al ., ) and antagonism (Atanasova et al ., ). We identified 153 putative SSCRPs in the GD12 genome (Studholme et al ., ), more than half (79) of which were expressed in GD12‐only and MSMs.…”

“…For example, during PGP, T. virens cultured hydroponically with maize or tomato roots deployed both common and plant‐specific transcriptional programmes, with important roles implicated for glycosyl hydrolases and transporters (Moran‐Diez et al ., ). Plant–pathogen–hyperparasite interactions induce specific gene expression (Steindorff et al ., ), including the over‐representation of transporters and carbohydrate‐active enzymes, similar to those identified during T. virens PGP (Moran‐Diez et al ., ). Such robustness and flexibility in the deployment of different genome components to achieve biocontrol suggests that different modes of pathogen perception feed into a convergent network.…”

“…Some SSCRPs are likely to function as potential effector molecules that collaborate in biocontrol and PGP. Consistent with this, in other Trichoderma species, SSCRPs have been shown to be up‐regulated during PGP (Moran‐Diez et al ., ), during induction of systemic resistance (Lamdan et al ., ) and during biocontrol (Atanasova et al ., ). Thus, the expanded repertoire of SSCRPs unique to GD12 may contribute to its dual biocontrol and PGP properties.…”

Functional Characterization of TvCyt2, a Member of the p450 Monooxygenases From Trichoderma virens Relevant During the Association With Plants and Mycoparasitism

“…Trichoderma spp. are able to establish such interactions, inducing massive changes at transcriptomic and metabolomic level (Morán-Diez et al 2015;Rubio et al 2012), and some of these metabolites have been found, not only to directly inhibit the growth of pathogenic microorganisms, but also increase disease resistance triggering the defense system in plants (induced systemic resistance) (Vos et al 2015). Furthermore, metabolitepretreated plants responded to a pathogen attack much faster or more intensively (Hermosa et al 2012;Shoresh et al 2010;Verhagen et al 2011), a mechanism known as priming (Conrath 2011).…”