%0 Journal Article
%T Calcium-mediated perception and defense responses activated in plant cells by metabolite mixtures secreted by the biocontrol fungus Trichoderma atroviride
%A Lorella Navazio
%A Barbara Baldan
%A Roberto Moscatiello
%A Anna Zuppini
%A Sheridan L Woo
%A Paola Mariani
%A Matteo Lorito
%J BMC Plant Biology
%D 2007
%I BioMed Central
%R 10.1186/1471-2229-7-41
%X Here, we investigated the effects on plant cells of metabolite complexes secreted by Trichoderma atroviride wild type P1 and a deletion mutant of this strain on the level of cytosolic free Ca2+ and activation of defense responses. Trichoderma culture filtrates were obtained by growing the fungus alone or in direct antagonism with its fungal host, the necrotrophic pathogen Botrytis cinerea, and then separated in two fractions (>3 and <3 kDa). When applied to aequorin-expressing soybean (Glycine max L.) cell suspension cultures, Trichoderma and Botrytis metabolite mixtures were distinctively perceived and activated transient intracellular Ca2+ elevations with different kinetics, specific patterns of intracellular accumulation of reactive oxygen species and induction of cell death. Both Ca2+ signature and cellular effects were modified by the culture medium from the knock-out mutant of Trichoderma, defective for the production of the secreted 42 kDa endochitinase.New insights are provided into the mechanism of interaction between Trichoderma and plants, indicating that secreted fungal molecules are sensed by plant cells through intracellular Ca2+ changes. Plant cells are able to discriminate signals originating in the single or two-fungal partner interaction and modulate defense responses.Trichoderma spp. are ubiquitous free-living soil fungi which act as biocontrol agents against several fungal phytopathogens. They are commercially applied as biopesticides, thus limiting the abuse of chemical fungicides [1,2]. The antagonist activity of Trichoderma depends on multiple synergistic mechanisms, including a direct interaction with the pathogenic partner (mycoparasitism), as well as indirect mechanisms based on competition for space and nutrients [3,4]. Trichoderma strains are rhizosphere competent, i.e. able to grow in association with plant roots, and can actually penetrate the first few layers of plant tissues [5,6]. The effects of Trichoderma colonization on plants inc
%U http://www.biomedcentral.com/1471-2229/7/41