Genetic Transformation With The Pea Catalase Gene In Maize

The corn is important in the agriculture production,so it seems to be important to carry on the corn heredity breeding and gene improvement in our country. In maize genetic engineering,however, undesirable problems still exist such as genotype-dependence, somaclonal variation of regenerants from long time in vitro culture, phenotypic aberrations such as albinism and reduced fertility.These weaknesses result in big difficulty to the corn seed selection and developments of the good cultivation species. Therefore, establishment of a genotype-free and short transformation cycle is one of the important tasks facing maize genetic engineering.In our research, the shoot apex of elite cultivar (chang7-2) has been used as the receptor for the agrobacterium-mediated transformation. We have found an improved transformation protocol which can solve the problems above: 40 days to get transformed shoots, shorter than at least sever months before; independence of genotype and no somaclonal variation because of avoiding dedifferentiation course; higher transformation frequency(6%).In the first research, one monocotyledon expression vector was constructed: pCUA-tr-cat-als. Using the LBA4404 carrying the above vector, the maize shoot apexes were transformed. PCR and PCR-Southern analysis of the genomic DNA from transgenic plants showed that the foreign gene has integrated into maize genome.After plants were cultivated with 15% (w/v) PEG-6000 for 5 days, the non-transgenic plants became dying away, whereas the transgenic plants were still alive.The result of the experiment showed that in drought stress the transgenic plants were stronger.In conclusion, the gene tr-cat was transformed into maize, and the transgenic plants showed improved tolerance to drought stress.That's good value to the corn heredity breeding.