A plate confrontation experiment is commonly used to study the mechanism by which Trichoderma spp. antagonize and parasitize other fungi. Previous work with chitinase gene expression (ech42) during the precontact period of this process in which cellophane and dialysis membranes separated Trichoderma harzianum and its host Rhizoctonia solani resulted in essentially opposite results. Here, we sho...

The goal of this project is to develop molecular tools to control rice sheath blight disease. Toward this end, a subtracted rice copy-DNA (cDNA) (only the expressed DNA) library was created to identify differentially expressed genes at the early interface between a tolerant rice cultivar ‘Jasmine 85’ and a highly virulent Rhizoctonia solani isolate. R. solani-induced message RNAs were selected ...

Several Trichoderma virens (syn. Gliocladium virens) strains have good biocontrol activity against Rhizoctonia solani on cotton but lack some of the commercially desirable characteristics found in other Trichoderma species. In an attempt to combine these desirable characteristics, we used a highly effective biocontrol strain of T. virens in protoplast fusions with a strain of T. koningii, which...

A laboratory and green house experiment was carried out on the comparative antagonistic performance of four different bioagents (Aspergillus sp., Gliocladium virens, Trichoderma harzianum and T. viride) isolated from soil against Rhizoctonia solani. Under laboratory conditions, T. harzianum exhibited maximum (75.55%) mycelial growth inhibition of R. solani This was followed by T. viride, which ...

The role of the Trichoderma harzianum endochitinase (Ech42) in mycoparasitism was studied by genetically manipulating the gene that encodes Ech42, ech42. We constructed several transgenic T. harzianum strains carrying multiple copies of ech42 and the corresponding gene disruptants. The level of extracellular endochitinase activity when T. harzianum was grown under inducing conditions increased ...

Validamycin A decreased the biomass and extracellular protein produced by cultures of Rhizoctonia solani A79 grown on medium containing cellulose as the carbon source. In the presence of the antibiotic, the production of inducible enzymes active on filter paper (FPase), carboxymethylcellulose (CMCase) and (cellobiase) was decreased, but not the production of constitutive enzymes involved in hem...