3.1.3. Transformation of E. coli
After linking with gfp fragment by T4 ligase, the recycled 4.8 kb fragment was transformed to E.coli. The bacterial colony growing on the chloramphenicol medium was showed in Fig. 6. Extracted transformant plasmid was used to recombine the plasmid through enzyme digestionwithHindIII and ECOlI, which was linked with the two fragments to produce two new fragments with the same size of 6.8 kb (detected by electrophoresis). The size of the plasmids indicated the right insertion.
3.1.4. GFP transformation of F. oxysporum strain F-H.SY0975
3.1.4.1. Preparation of protoplast. Microscopy was used to observe the production of protoplast after going through one hour enzymolysis with Driselase buffer. The morphology of the protoplast was shown in Fig. 8a, whose product mode was: top-end release (Fig. 8b), and intermediate release (Fig. 8c).
3.1.4.2. Stability verification of F. oxysporum F-H.SY0975
green fluorescent protein marking transformants.In order to detect the genetic stability of green fluorescent protein gene in transformant genome, the third culture ofF. oxysporum GFP transformants was inoculated onto the PDA medium without hygromycin. After continuous culturing for five generations, it was later inoculated onto the hygromycin medium. The lines witnessing normal growth were a stable transformant. GFP expression was maintained in mycelia (results not presented).