Langebio - Cinvestav. MŽxico.
HERRERA-ESTRELLA A*, Hern‡ndez, M., Alcar‡z, L., Ibarra, E., Vega, J. and Esquivel-Naranjo, U.National Laboratory of Genomics for Biodiversity, Cinvestav Campus-Guanajuato, 36821 Irapuato, Gto. Mexico. aherrera@ira.cinvestav.mx *Corresponding author: Km. 9.6 libramiento Norte Carretera Irapuato-Le—n, CP 36821 Irapuato, Guanajuato, MŽxico. E-mail aherrera@ira.cinvestav.mx
National Laboratory of Genomics for Biodiversity, Cinvestav Campus-Guanajuato, 36821 Irapuato, Gto. Mexico. aherrera@ira.cinvestav.mx *Corresponding author: Km. 9.6 libramiento Norte Carretera Irapuato-Le—n, CP 36821 Irapuato, Guanajuato, MŽxico. E-mail aherrera@ira.cinvestav.mx
RESUMEN (ABSTRACT)
Several species belonging to the genus Trichoderma are mycoparasites used as biocontrol agents of a wide range of aerial and soil-borne plant pathogens. Biocontrol by Trichoderma involves competition, mycoparasitic activity and induction of the plant defense response. Mycoparasitism by Trichoderma is a complex process; upon recognition of a host they form specialized structures, secrete a complex set of cell wall degrading enzymes, and produce secondary metabolites that affect membrane structure. We have compared the genomes of three species of the genus Trichoderma; two of them widely used as biocontrol agents due to their mycoparasitic activity (T. atroviride & T. virens), and one of them with no mycoparasitic activity (T. reesei). These analyses allowed us to identify set of genes shared only between the two mycoparasites and genes that are unique to a given species. It is commonly assumed that during the interaction with the host there are important changes in gene expression. We have analyzed such changes in the interaction of different Trichoderma species with a host by direct counting of cDNA sequences. Our analysis suggests that there are, species-specific responses, directly related to the corresponding mechanism of action of the parasite. Furthermore, this analysis indicates that there a defense mechanism is activated by the parasite prior to contact with the host. Additionally, we have analyzed the changes in gene expression triggered by environmental cues leading to the production of asexual spores (conidia), since this is the mechanism of survival and dispersal of these organisms. The later analysis has led us to identify hundreds of genes involved in this process, some of which are common to different cues.