Total Like The Head Mold The Spsr The Cloning And Expression In Escherichia Coli,

Plant parasitic nematodes were one of important pathogens. They were dangerous to crops in all over the world. The previous bio-control products were live microorganisms; The products now used were largely fat-soluble. Syncephalastrum racemosum that effective in control of root-knot nematodes had already been screened. Of its fermentation broth, there were properties that resembles as in an acidic and heat-stabled to that of the aspartic proteinase. Thereby, syncephapepsin of S. racemosum is extremely significant to be further studied in control of nematodes diseases.Syncephapepsin, as an enzyme, is gene-encoded and thus the gene was cloned employing with RT-PCR method. Four vectors of pET vector system were chosen to express the enzyme in E. coli BL21(DE3). The main results were as follows: 1. The total RNA was obtained from fungus Syncephalastrum racemosum. The gene of aspartic proteinase syncephapepsin(SPSR) was amplified by RT-PCR.2. The gene SPSR was inserted into pUC 18 vector to construct pUC 18-SPSR. The fragment was analysed and the sequence was 656bp. The homogeny of fragment and syncephapepsin was about90%byBLAST.3.pET-22b(+), pET-28a(+), pET-30a(+), pET-40b(+)ofpET vector system were chosen to construct expression vectors. The expression stains were screened by SDS-PAGE method after induced by IPTG The relative molecular weight of expressed protein was about 38.0KDa. The conclusion is that cloned vector pUC18-SPSR and pET vectors were constructed; The gene can be expressed in E. coli system.