PMI基因作为选择标记的植物表达载体构建及其在雪柑转基因中的应用

The plant expression vectors pCAMBIA1301PMI and pBIPMI were constructed by substituting Escherichia coli phosphomannose-isomerase(PMI)gene for hpt gene of pCAMBIA1301 and gus gene of pBI121.Epicocyl explants of Xuegan sweet orange(Citrus sinensis L.Osbeck)were inoculated with Agrobacterium-tumefaciens EHA105-pCAMBIA1301PMI and EHA105-pBIPMI and subsequently selected on medium supplemented with a combination of 25 g/L mannose and 5 g/L sucrose as a carbon source.The transformation efficiency rate was 27.7%when transformed by pCAMBIA1301PMI and 12.7%by pBIPMI.Genetic transformation was confirmed by chlorophenol red assay and PCR,indicating that a new method for obtaining transgenic Xuegan plants was developed using PMI/mannose selection system.