title: The ThPG1 endopolygalacturonase is required for the trichoderma harzianum-plant beneficial interaction.
abstract: Considering the complexity of the in vivo interactions established by a mycoparasitic biocontrol agent at the plant rhizosphere, proteomic, genomic, and transcriptomic approaches were used to study a novel Trichoderma gene coding for a plant cell wall (PCW)-degrading enzyme. A proteome analysis, using a three-component (Trichoderma spp.-tomato plantlets-pathogen) system, allowed us to identify a differentially expressed Trichoderma harzianum endopolygalacturonase (endoPG). Spot 0303 remarkably increased only in the presence of the soilborne pathogens Rhizoctonia solani and Pythium ultimum, and corresponded to an expressed sequence tag from a T. harzianum T34 cDNA library that was constructed in the presence of PCW polymers and used to isolate the Thpg1 gene. Compared with the wild-type strain, Thpg1-silenced transformants showed lower PG activity, less growth on pectin medium, and reduced capability to colonize tomato roots. These results were combined with microarray comparative data from the transcriptome of Arabidopsis plants inoculated with the wild type or a Thpg1-silenced transformant (ePG5). The endoPG-encoding gene was found to be required for active root colonization and plant defense induction by T. harzianum T34. In vivo assays showed that Botrytis cinerea leaf necrotic lesions were slightly smaller in plants colonized by ePG5, although no statistically significant differences were observed.
authors: Centro Hispano-Luso de Investigaciones Agrarias (CIALE). Departamento de Microbiología y Genética, Universidad de Salamanca, Campus de Villamayor, C/ Duero 12. 37185 Salamanca, Spain.
authors: Eugenia
authors: E
authors: Morán-Diez
authors: Rosa
authors: R
authors: Hermosa
authors: Patrizia
authors: P
authors: Ambrosino
authors: Rosa E
authors: RE
authors: Cardoza
authors: Santiago
authors: S
authors: Gutiérrez
authors: Matteo
authors: M
authors: Lorito
authors: Enrique
authors: E
authors: Monte
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000382:microbiology; D003001:Cloning, Molecular; D020224:Expressed Sequence Tags; D005656:Fungal Proteins / Q000235:genetics / Q000502:physiology*; D020869:Gene Expression Profiling; D015723:Gene Library; D020868:Gene Silencing; D023281:Genomics; D018551:Solanum lycopersicum / Q000382:microbiology*; D008969:Molecular Sequence Data; D010572:Pest Control, Biological; D010802:Phylogeny; D011096:Polygalacturonase / Q000235:genetics / Q000502:physiology*; D040901:Proteomics; D014242:Trichoderma / Q000201:enzymology* / Q000235:genetics / Q000502:physiology
chemical_list: D005656:Fungal Proteins; D011096:Polygalacturonase