Gene Overexpression, Silencing and Disruption as Functional Genomics Tools in Trichoderma pp. 223-244
Authors: (Rosa Hermosa, Rosa E. Cardoza, M. Belén Rubio, Eugenia Morán, Santiago Gutiérrez, Enrique Monte, Spanish-Portuguese Centre of Agricultural Research (CIALE), Departamento de Microbiología y Genética, Universidad de Salamanca, Campus de Villamayor, Salamanca, Spain, and others)
Abstract: Species of the anamorphic genus Trichoderma are ubiquitous and typically soil-borne or wood-decaying fungi. In addition, they are able to grow rapidly on many substrates, producing economically important metabolites such as industrial enzymes (cellulases and hemicellulases) and antifungal antibiotics. Some of them are used in the biological control of plant diseases caused by phytopathogenic fungi and in fungal-plant interactions, which are benefitial for plant. Current understanding of the molecular biology of Trichoderma has allowed this fungus to be engineered to facilitate functional gene analysis. The use of integrative transformation systems and the search for selection markers that will yield stable transformants have allowed more flexible transformation methods to be designed in Trichoderma. Although gene disruptants from different Trichoderma species have been obtained, to date it has been hard to generate them in any strain. This lack of a suitable procedure to disrupt genes in species such as T. harzianum, the organism most widely cited as a biocontrol agent, has led to a serious limitation in the characterization of gene functions. Over the past few years, gene overexpression and silencing have been the methods of choice for the successful collection of transformant Trichoderma strains to carry out functional analysis of "biocontrol" and "plant-defense eliciting" genes.