Trichoderma – a promising plant growth stimulator and biocontrol agent

Biocontrol, or Biological Control, can be defined as the use of natural organisms, or genetically modified, genes or gene products, to reduce the effects of undesirable organisms to favor organisms useful to human, such as crops, trees, animals and beneficial microorganisms. The fungus Trichoderma, a low cost biocontrol agent that can establish itself in different pathosystems, has moderate effects on soil balance and does not harm beneficial organisms that contribute towards pathogen's control. Fungi of the genus Trichoderma are soilborne, green-spored ascomycetes that are ubiquitous in nature. Trichoderma spp. are characterized by rapid growth, mostly bright green conidia and a repetitively branched conidiophore structure. As opportunistic plant symbionts and effective mycoparasites, numerous species of this genus have the potential to become commercial biofungicides. This biocontrol agent has no harmful effects on humans, wild life and other beneficial organisms. It is safe and effective in both natural and controlled environments that does not accumulate in the food chain. Trichoderma strains used as biocontrol agents can act: a) colonizing the soil and/or parts of the plant, occupying a physical space and avoiding the multiplication of the pathogens; b) producing cell wall degrading enzymes against the pathogens; c) producing antibiotics that can kill the pathogens; d) promoting the plant development and e) inducing the defensive mechanisms of the plant. The extensive studies on diverse physiological traits available and still progressing for Trichoderma make these fungi versatile model organisms for research on both industrial fermentations as well as natural phenomena.