2.2.1.1. E. coli transformation.The resulting PCR fragment
was digested with HindIII and COlI, and the digested products were purified by using Universal DNA Purification Kit (TIAN GEN, DP214–02), cloned into the Trans 109 (de-stroyed by blunting with T4 DNA polymerase).
2.2.1.2. Protoplast preparation and transformation.
Protoplast were prepared from F.oxysporumand co-transformed with
25ll of plasmid pBC-hygro-GFP, which harbours the homologous gfp gene, using the PEG-CaCl2 mediated transfer of DNA as described previously (Bae and Knudsen, 2000).
2.2.2. Screening for GFP expression
Putative resistant transformants were transferred to PDA containing 300 mg/ml hygromycin B and screened for GFP expression. GFP expression was initially detected inF. oxysporumby microscopic screening using NIKON TS-100 with excitation filters at 450–490 nm, using 488 nm excitation line.