| Summary: | 碩士 === 國立中興大學 === 植物學系 === 81 === Genes for insecticidal crystal protion (cry genes) were
isolated form various Bacillus thurgiensis strains by
polymerase chain reaction (PCR) technology. There cry genes
were constructed in different promoter containing E.coli
expression vectors, pUNG and pTrc99A respectivly. The pUNG
vector contain the promoter of lacZ operon and the pTrc99A
vector contains the trc promoter. Results of insecticidal
activity assay indicated that the cry gene in pTrc99A has
better expression than that of in pUNG. However,these changed
did not affect the insecticidal activity to tested insects. A
cry gene modified (BTM) to increase its expression in plaht was
also tested in E.coli. This maybe due to the codons of BTM
gene were not well recognized in E.coli. After transforming cry
genes , carried by a plasmid vector, into Erwinia herbicola,
the transformed E.herbicola could express insecticidal crystal
protein and show insecticidal activity to tested insects. These
transformed E.herbicola could retain on the leave of cabbage at
the natural environmental condition for about 7 day. To test
the stability of cry gene containing plasmid in E. herbicol,a
series of subculture in ampicillin free LB medium was performed.
The results indicated that the plasmid will be excluded form
the E.herbicola within few days in the ampicillin free culture
condition. Due to the low transformation efficiency of Brassica
plants, only five kanamycin resistant Brassica plants were
obtained and three of them werw detected to be cry gene
containing transgenic plants by PCR. However, only one plant
was further confirmed by the southern analysis.
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