Genetic Transformation And Verification Of SAMS Gene In Maize Inbred Line By Agrobacterium-Mediated

Drought is the first limiting factor in maize production, So drought-resistant gene was transferred into the maize, which has become an important measure. This study constructed expression vector pBI121-SAMS, And with the seedling shoot tips and zygote of maize inbred line as explants, the SAMS gene was transferred into the maize by using Agrobacterium-mediated in plant transformation, transgenic maize were identified by PCR and RT-PCR, T1 transgenic maize and non-modified maize were treated by using 18% PEG-6000 to simulate drought stress conditions. The results are as follows:1. The study obtained SAMS gene from Jinmai47 by PCR amplification, and constructed plant expression vector pBI121-SAMS that was regulated by 35S Promoter.2. Using kanamycin of different concentration to Ye 478 and Zheng58 in three leaf stage, The results show that the Optimal concentration is 20000mg/L,and time is about 10 days 3. 453 transgenic plants were obtained after having transformed 518 shoot tips. 16 T0 positive transgenic plants were screened by PCR, The frequency of transformation reached3.53%, 14 of them get seeds finally. 9 of T1 transgenic maize were transcription normally confirmed by RT-PCR. These indicated that SAMS genes had been integrated to corn genomes and normal expression4. Ye478 and Zheng58 maize zygotes were transformed for 50 respectively by using Agrobacterium-mediated in plant transformation. 32 plants were got from Ye478 inbred line, and 34 from Zheng58 inbred lines, but less per ear decreased. 3 of T1 positive plants from Ye478 and 4 of T1 positive plants from Zheng58 were got by kanamycin and PCR. It proved that the SAMS gene has been integrated to the genome of maize5. The study found that Leaf relative water content,Chlorophyll content,Proline content and SOD activity of transgenic maize were more than CK plants while Conductance and MDA content were less under the same water stress time. When the time reached 60h, Leaf relative water content,Chlorophyll content,Proline content and SOD activity of transgenic maize were 8.16%,20.02%,32.21%,22.77% higher than the physiological indexes of CK, but Conductance and MDA content were 14.38%,29.41% lower than them were in CK. We can conclude that genetically modified maize has improved the drought-resistance by introducing of the foreign SAMS genes.