The Effect Of Gene Targeting Efficiency On Rice Bel Gene Vectors With Different Homology Arm Length

Gene targeting is a technology that homologous recombination comes between exogenous DNA and predetemined bits in receptor genome. Homologous arm length of targeting vector is an important factor which affect the efficiency of targeting in the process of gene targeting. Rice Bel is the monooxygenase gene of cytochrome P450gene family. The product of Bel is CYP81A6, which is responsible for resistance of herbicide named bentazon in rice.In this study, we were trying to targete Bel gene in shijinB, a maintainer line of Oryza sativa L. ssp. Japonica by two different targeting vectors (pRB2and pRB4). On the one hand we can study the targeting efficiency of homologous arm length, and select the higher efficient targeting vector. On the other hand, we can obtain the Bel-targeting cytoplasimic male sterility (CMS) line by crossing the Bel-targeting transgenic shijinB rice with the CMS line, shijinA.The mainly results are as follows:1.128.9g rice callus were used and255transgenic plants were obtained using pRB2targeting vector;163.2g rice callus were used and104transgenic plants were obtained using pRB4targeting vector.2. The differentiation rate of transgenic callus using pRB2targeting vector is17.6%and the rate using pRB4targeting vector is13%. The differentiation rate of transgenic callus using pRB2vector was2.41times as the rate using pRB4vector. We have successfully detected a Bel-targeting transgenic rice that transformed using pRB2targeting vector, however, we didn’t detect Bel-targeting transgenic rice using pRB4targeting vector. Therefore, we preliminary think that the Bel gene targeting efficiency of pRB2is higher compared with that of pRB4.