Agrobacterium tumefaciens-mediated transformation (AtMT) has been widely used for generation of fungal transformants and recently applied to Beauveria bassiana. In this study to comprehend how the AtMT promoter influences on the expression of selection marker (hygromycin B resistance gene; hph), two different Ti-Plasmids were constructed: pCeg (gpdA promoter-based) and pCambia-egfp (CaMV 35S promoter-based). Putative transformants were subjected to the PCR, RT-PCR and qRT-PCR to inspect the T-DNA insertion rate and gene expression level. In conclusion, more than 80% of the colonies succeeded in AtMT transformation and the hph expression level of AtMT/pCeg colonies was higher than that of AtMT/pCambia-egfp colonies. This result can provide useful information on the AtMT of B. bassiana, especially antibiotics susceptibility and promoter-dependant expression level.

Entomopathogenic fungus, Beauveria bassiana can be used in integrated crop management and pharmaceutical applications. Recently some efforts have been given to the fungus to improve its biological performances, but low fungal transformation efficiency is one of the limitations. In this work, B. bassiana ERL1170 isolate was used for fungal transformation by restriction enzyme-mediated integration, where pBARKS1-Bbs-cecropinA was linearied using HindIII. The fungal transformation comprised two steps, preparation of competent blastospores and integration of the plasmid into the cells. To prepare competent blastospores, 2-d cultured blastospores were individually treated with 0.1, 0.2, 0.4 and 0.8 M lithium acetate (LiAc). Secondly in the integration step, concentration of LiAc and calcium chloride (CaCl2), and time period of heat shock were investigated as follows: LiAc, 1, 2 and 4 M; CaCl2, 50, 100 and 200 mM; and heat shock at 42℃, 20, 40 and 60 min. Consequently, combination of 0.2 M LiAc in preparing competent blastospores and 2 M LiAc and 200 mM CaCl2 in the second step showed the highest transformation efficiency. This work would be helpful in the fungal transformation of B. bassiana.