Cloning and characterization ofbgn16·3, coding for a β-1,6-glucanase expressed duringTrichoderma harzianummycoparasitism

Abstract

Aims: To clone and characterize the gene coding for BGN16·3, a β‐1,6‐glucanase putatively implicated in mycoparasitism by Trichoderma harzianum, a biocontrol agent used against plant pathogenic fungi. Methods and Results: Using degenerate primed PCR and cDNA library screening, we have cloned the cDNA coding BGN16·3. bgn16·3 showed a significant sequence identity (50%) to bgn16·1; however, they both have low identity to the previously cloned bgn16·2, allowing the identification of amino acid sequences putatively involved in the common catalytic activity of the three proteins. bgn16·3 is a single‐copy gene and highly homologous sequences are present in all tested Trichoderma species. bgn16·3 expression pattern is analysed by Northern blot, finding that it is expressed during the interaction of T. harzianum CECT 2413 with Botrytis cinerea, supporting the implication of the enzyme in the mycoparasitic process. Conclusions: The cloned bgn16·3 completes the knowledge on the β‐1,6‐glucanase isozyme system from T. harzianum CECT 2413. A highly homologous gene is present in all analysed Trichoderma strains. bgn16·3 is expressed under few specific conditions, including the mycoparasitic process. Significance and Impact of the Study: This study contributes to the knowledge of β‐1,6‐glucanases. It implicates this group of enzymes in the mycoparasitism by some biocontrol agents such as T. harzianum.

Expression of Saccharomyces cerevisiae RER2 Gene Encoding Cis-Prenyltransferase in Trichoderma atroviride Increases the Activity of Secretory Hydrolases and Enhances Antimicrobial Features

“…The aim of this study was to construct novel strains of T. atroviride with elevated hydrolytic capabilities. It is well known that during a direct attack, Trichoderma degrades the cell wall of a fungal pathogen with a variety of secreted extracellular enzymes [ 42 ]. Based on this knowledge, we decided to increase the hydrolytic activity of the new strains.…”