Isolation And Functional Analysis Of Gamma-tocopherol Methyltransferase(γ-TMT) In Soybean

Tocopherols, commonly known as vitamin E, are a class of lipid-soluble antioxidants synthesized only by plants and other photosynthetic organisms. Tocopherols are essential components of the human diet because they perform numerous critical functions including quenching and scavenging various reactive oxygen species and free radicals. Because of these and other activities, it can resist stress. Of the four naturally occurring tocopherols,α-tocopherols has the highest vitanin E activity and is preferentially absorbed and distributed throughout the body. However,α-tocopherols is present only as a minor component while its biosynthetic precursor,γ-tocopherols, is present at high level.To inhanceα-tocopherols level by molecular biotechnology, the Gamma-tocopherol methyltransferase in Soybean, the full-length cDNA ofγ-TMT was obtained from Sobean by RT-PCR and was transformed into the genome of Arabidopsis and we are eager to know that whether high levelα-tocopherols in transgenic Arabidopsis can increase resistance to the plant pathogen. So the transgenic Arabidopsis was infected by Pseudomonas syringae pv.tomato DC3000 .The results obtained through the present research are as follows:1. The full-length cDNA ofγ-TMT gene was isolated by RT-PCR from Soybean. A recombinant vector PET-TMT was constructed forγ-TMT gene prokaryotic expression and A recombinant vector PBI121-TMT was constructed forγ-TMT gene expression in plant. Then we obtained high levelγ-TMT activity in E.coli.BL21 and Homozygousγ-TMT gene transgenic line 1#,5#,7#,8#. ELISA showed thatγ-TMT gene activity was the highest in 1# and HPLC showed thatγ-TMT overexpression in Arabidopsis resulted in a 3-6 fold increase relative to wild type .2. The pathogen DC3000(P.syringae pv.tomato DC3000)was inoculated to homozygous transgenic line 1#,5#,7# and wild type. The result showed that We found that there is no resistance to P.syringae pv.tomato DC3000 in transgenic plant and its leaves turn yellow after 3 days in transgenic plant and wild type. Both transgenic plant and wild type has...