Agrobacterium tumefaciens-mediated transformation ofCry I A(b) gene toTrichoderma harzianum

Abstract

In this study,Cry IA(b) gene was successfully transferred into the biocontrol fungusTrichoderma harzianum with an efficiency of 60–180 transformants per 106 spores by usingAgrobacterium tumefaciens-mediated transformation. Putative transformants were analyzed to test the presence ofCry IA(b) gene by Southern blot. Most transformants contained a single T-DNA copy. RT-PCR analysis showed that theCry IA(b) gene was transcribed. Antifungal activities and insecticidal activities of the transformants were examined. There was no obvious difference in antifungal activities between the transformants and their wild strains. The modified mortalities of the transformants T1 and T2 were 69.57% and 91.30%, respectively. The tranformation system mediated byA. tumefaciens proved to be a powerful tool for the filamentous fungi transformation and functional genomic study with its high transformation frequency, simplicity of T-DNA integration, and genetic stability of transformants.