Aspartyl protease from Trichoderma harzianum CECT 2413: cloning and characterization The GenBank/EMBL/DDBJ accession number for the sequence reported in this paper is AJ276388.

Delgado-Jarana, Jesús; Rincón, Ana María; Benı́tez, Tahı́a

doi:10.1099/00221287-148-5-1305

Cited by 55 publications

(19 citation statements)

References 40 publications

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“…Previous studies of papA gene expression were carried out with T. harzianum, where it was shown that papA is repressed by ammonium, glucose, and glycerol but induced by organic nitrogen sources. Additionally, binding sites for AreA and MYC were found in the promoter region (19). In contrast, our promoter analysis identified only one MYC site (MYC1) and multiple binding sites for Xyr1, Cre1, AceI, and a novel putative motif.…”

Section: Discussionmentioning

confidence: 41%

Identification of Mycoparasitism-Related Genes in Trichoderma atroviride

Reithner

Ibarra-Laclette²,

Mach

et al. 2011

Appl Environ Microbiol

110

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A high-throughput sequencing approach was utilized to carry out a comparative transcriptome analysis of Trichoderma atroviride IMI206040 during mycoparasitic interactions with the plant-pathogenic fungus Rhizoctonia solani. In this study, transcript fragments of 7,797 Trichoderma genes were sequenced, 175 of which were host responsive. According to the functional annotation of these genes by KOG (eukaryotic orthologous groups), the most abundant group during direct contact was "metabolism." Quantitative reverse transcription (RT)-PCR confirmed the differential transcription of 13 genes (including swo1, encoding an expansin-like protein; axe1, coding for an acetyl xylan esterase; and homologs of genes encoding the aspartyl protease papA and a trypsin-like protease, pra1) in the presence of R. solani. An additional relative gene expression analysis of these genes, conducted at different stages of mycoparasitism against Botrytis cinerea and Phytophthora capsici, revealed a synergistic transcription of various genes involved in cell wall degradation. The similarities in expression patterns and the occurrence of regulatory binding sites in the corresponding promoter regions suggest a possible analog regulation of these genes during the mycoparasitism of T. atroviride. Furthermore, a chitin-and distance-dependent induction of pra1 was demonstrated.Due to hazardous chemical fungicides affecting human health (4) and the environment (9), the application of biological control agents like Trichoderma spp. is a promising alternative for plant protection (17). Members of the genus Trichoderma (teleomorph Hypocrea) are potent mycoparasitic fungi that not only compete for nutrients but also secrete cell wall-degrading enzymes (CWDEs) such as chitinases, glucanases, and proteases, among others, and excrete secondary metabolites that are active against a number of plant-pathogenic fungi (15,28,29,41,58). In addition to an increase in enzyme secretion during interactions with host fungi, it was shown previously that differentiation processes occur, leading to morphological changes and the formation of penetration structures in mycoparasitic Trichoderma spp. (7,22). Interestingly, mycoparasitism is not a mere result of physical contact but may be proceeded by an early recognition process that leads to the induction of gene expression of hydrolytic enzymes (e.g., prb1 [18] and ech42 [67]).In recent years, a number of studies have identified enzymes and effectors involved in host recognition and the mycoparasitic responses of Trichoderma (40, 46, 51); however, their modes of action and the mechanisms determining host specificity remain poorly understood. Mainly expressed-sequencetag (EST) libraries of different Trichoderma strains obtained under various growth conditions have contributed significantly to the large-scale identification of active genes (63, 64). Additionally, diverse DNA array experiments have determined that an expansin-like protein, aspartyl proteases, and hydrophobins, among others, are involved in the biocontrol a...

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Section: Discussionmentioning

confidence: 41%

Identification of Mycoparasitism-Related Genes in Trichoderma atroviride

Reithner

Ibarra-Laclette²,

Mach

et al. 2011

Appl Environ Microbiol

110

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“…We used a differential display technique with RNA isolated from mycelia obtained by cultivating T. harzianum CECT 2413 in media containing either 2 or 0.2% glucose and buffered at either pH 3 or pH 6 as described in Materials and Methods. Media were buffered because a number of genes involved in the antagonism of T. harzianum, such as genes for proteases (9) and glucanases and chitinases (M. A. Moreno-Mateos and T. Benítez, unpublished data), are pH controlled. Gene expression controlled by pH has also been described for fungal pathogens for insects and mammals, such as Metarhizium anisopliae and Candida albicans (7,48).…”

Section: Resultsmentioning

confidence: 99%

Glucose Uptake in Trichoderma harzianum : Role of gtt1

2003

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Using a differential display technique, the gene gtt1, which codes for a high-affinity glucose transporter, has been cloned from the mycoparasite fungus Trichoderma harzianum CECT 2413. The deduced protein sequence of the gtt1 gene shows the 12 transmembrane domains typical of sugar transporters, together with certain residues involved in glucose uptake, such as a conserved arginine between domains IV and V and an aromatic residue (Phe) in the sequence of domain X. The gtt1 gene is transcriptionally regulated, being repressed at high levels of glucose. When carbon sources other than glucose are utilized, gtt1 repression is partially alleviated. Full derepression of gtt1 is obtained when the fungus is grown in the presence of low carbon source concentrations. This regulation pattern correlates with the role of this gene in glucose uptake during carbon starvation. Gene expression is also controlled by pH, so that the gtt1 gene is repressed at pH 6 but not at pH 3, a fact which represents a novel aspect of the influence of pH on the gene expression of transporters. pH also affects glucose transport, since a strongly acidic pH provokes a 40% decrease in glucose transport velocity. Biochemical characterization of the transport shows a very low K m value for glucose (12 M). A transformant strain that overexpresses the gtt1 gene shows a threefold increase in glucose but not galactose or xylose uptake, a finding which confirms the role of the gtt1 gene in glucose transport. The cloning of the first filamentous ascomycete glucose transporter is the first step in elucidating the mechanisms of glucose uptake and carbon repression in aerobic fungi.Filamentous fungi are ubiquitous organisms able to obtain energy from very different substrates. Consequently, some of them are important pathogens for other fungi, insects, plants, and animals, and some are quite relevant in biotechnology. The wide use of strains of the genus Trichoderma is based on their ability to degrade plant polymers, such as cellulose (20), and to antagonize other fungi (18). For this reason, strains of Trichoderma harzianum have been commonly used as agents for the biocontrol of plant pathogenic fungi. Several mechanisms have been considered to be key factors in antagonistic interactions: lysis of host cell walls, antibiosis, competition for nutrients, induced resistance in plants, and inactivation of host enzymes (15). Both the lysis of fungal cell walls and the efficient use of available nutrients are based on the ability of Trichoderma strains to obtain ATP from the metabolism of different sugars, such as those obtained from polymers widespread in vegetal and fungal sources: cellulose, hemicellulose, xylan, mannan, arabinan, and chitin, among others.The majority of the enzymes involved in the degradation of these polymers are repressed by glucose (2, 20, 24). The mechanism(s) by which glucose repression is triggered remains undiscovered, despite the large amount of information obtained from Saccharomyces cerevisiae (13). Unlike that of the unicellular a...

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“…This sequence, together with other MYC sequences, have been considered regulatory regions characteristic of genes with a direct role in mycoparasitism, such as chit42 or papA genes (Delgado-Jarana et al, 2002). Also pathogenicity factors such as components of specialized structures (those of coiling, appresoria) are recognized to be controlled by environmental pH (Prusky and Yakoby, 2003;Davis, 2003).…”

Section: Strainmentioning

confidence: 99%