CLONING AND EXPRESSION OF TWO GARLIC VIRUS COAT PROTEIN GENES
两株大蒜病毒外壳蛋白基因的克隆及其在大肠杆菌中的表达

The coat protein(CP) genes of garlic mosaic virus(GMVc) and garlic latent virus(GLVc) isolated from garlic(Allium) plants in Tianjin, China, were amplified from an established cDNA library by PCR method and subsequently expressed in E. coli. using the pET-30a expression system. The determined sequences of GMVc and GLVc CP genes show that the complete GMVc CP gene has 867 nucleotides encoding 289 amino acids. It has 88.5% and 97.2% homology, at the levels of nucleotide and amino acid, respectively, to a reported GMV, indicating that it belongs to Potyvirus. The complete GLVc CP gene has 885 nucleotides coding for 294 amino acids. It has 73.6% and 90.9% homologous percents, in nucleotide and amino acid, respectively, compared to a previously reported GLV, suggesting that it is a member of Carlavirus. The expressed products presented in inclusion body and were analyzed by SDS-PAGE. The molecular weights of GMVc and GLVc CPs appear in 32 kD and 34 kD size, respectively, which are consistent with the deduced sizes of these two CPs. These data will be virtually significant to the further investigation of viruses infecting parlic plant, the control of garlic virus diseases and the production of virus-freed garlic plants.