Construction and transformation for the antisense expression vector of the polyphenol oxidase gene in Yali pear

摘要

To inhibit the browning process in fruits of Yali pear, in this paper, antisense gene techniques were used to reduce the expression of PPO gene. A cDNA fragment of 450 bp, which is located at the 3′ terminal of the polyphenol oxidase (PPO) gene, was amplified from Yali pear using the RT-PCR method, then the antisense expression vector was constructed by inserting the fragment of the Yali pear PPO gene between the CaMV promoter and NOS terminator of the expression vector pBI121 in a reverse orientation. After that, with the agrobacterium-mediated method, the PPO antisense gene was transformed into Yali pear shoots. Northern blot analysis and enzyme activity assay showed that the PPO activities in the transgenic Yali pear shoots were significantly decreased, compared with the non-transformed Yali pear shoots. This lays a good foundation for breeding new varieties of pears with browning resistance in the future.