Transgenic plant regeneration of tobacco (Nicotiana tabacum) haboring mammalian cyp2e1 gene / 生物工程学报

CYP2E1 enzyme encoded by cyp2e1 gene plays an important role in metabolism of heterogeneous organics in mammalian liver cells. The transgenic plant with cyp2e1 can metabolize various low molecular weight organic pollutants. However, it is unclear the mechanism of expression control of cyp2e1 in transgenic plant. In this study, plasmid pSLD50-6 with cyp2e1 and pKH200 with gus as control were transformed into Agrobacterium tumefaciens GV3101 separately. Then, the cyp2e1 or gus genes were transferred into tobacco (Nicotiana tabacum) and the transgenic plants were regenerated via Agrobacterium tumefaciens method. Real-time quantitative PCR (qRT-PCR) was used to analyze the cyp2e1 gene expression. The expression of cyp2e1 in transgenic tobacco with cyp2e1 decreased obviously treated by ethyl alcohol and reduced slightly by benzene and toluene, while it enhanced by acetone, formaldehyde and oxygen deficit in different levels. In addition, the gene expression of NADPH-P450 oxidoreductase and cytochrome b5 enzyme in the transgenic tobacco with cyp2e1 were increased significantly treated by benzene, which showed that NADPH-P450 oxidoreductase and cytochrome b5 enzyme in transgenic tobacco have relation with CYP2E1 detoxication process. It suggested that the NADPH-P450 oxidoreductase and cytochrome b5 enzyme in transgenic plant formed the requirement in mammalian and participated in the electron transport chain of CYP2E1 enzyme catalytic process.

Development of SNP Marker and CAPS Marker Linked to ACC Synthase Gene in Different Sexual Phenotypes of Cucumber / 生物化学与生物物理进展

Ethylene regulates sex expression in cucumber plants (Cucumis sativus L.). ACC synthase is a key factor during the ethylene biosynthesis. Pairs of PCR primers were synthesized corresponding to the conserved sequences of ACC synthase gene family. The 1 188 bp DNA fragment of ACC synthase gene (CS-ACS2) was amplified from genomic DNA of 8 different sexual phenotypes of cucumber respectively (GenBank accession number is DQ115884～DQ115886 and DQ115875～DQ115879). 8 SNPs have been identified by sequences analysis between 3 monoecious lines and 5 subgynoecious lines and gynoecious lines, which including 4 A←→G and 4 T←→C transition. Of these 8 SNPs, one locus is in intron and 7 loci in exons. Of the 7 SNPs located in exons, 3 SNPs are non-coding SNPs and 4 SNPs are coding SNPs (cSNPs) of which 3 induced changes of encoding amino acid of ACC synthase. The results of SNPs from subgynoecious lines and gynoecious lines suggest that single nucleotide mutation events of CS-ACS2 might be correlated with the development of subgynoecious lines and gynoecious lines in cucumber. Furthermore, CAPS marker C-MT705 was developed for identifying elite subgynoecious cultivar MT-705, which could be valuable in cucumber breeding. Besides, the SNPs and CAPS markers obtained in the study enriched molecular markers of cucumber.