Study On Tolerance To Heavy Metal Of Ferritin Gene Over-expression And Transformation Of P.davidiana×P.bolleana

The T₂ generation transgenic tobacco seedlings,which had been introduced tobacco ferritin gene(NtFer1) into their genomes and whose seeds also had been subjected to Kanamycin screening,were transplanted into individual bottle of MS media containing (0/400/800μmol/L)Pb²⁺,(0/100/200μmol/L)Cd²⁺,(0/75/150μmol/L)Co²⁺, (0/500/1000μmol/L)Zn²⁺,(0/50/100μmol/L)Ni²⁺,(0/4/8mmol/L)Mn²⁺ and grow for one month. Then,the plant height,fresh weight,chlorophyll content,POD activity,SOD activity and MDA content were measured to compare with the non-transformants.The results of physiologic characters responding to heavy metal tolerance indicated that the tobacco strains over-expressing the NtFerl gene have an obvious better average performance under the condition of heavy metal ions tolerance,and on the whole could commendably dynamicly balance the reactive oxygen between producing and eliminating in terms of tolerance.These demonstrate that the phenomenon of over-expression of ferritin gene for tobacco can enhance the capacity for seedling of self- accommodating and self- recovering to the tolerance for heavy metal ions of Pb²⁺,Cd²⁺,Mn²⁺,Co²⁺ and Ni²⁺,including improve the photosynthetic rate;restrain the decompounding of chlorophyll;increase the activity of POD and SOD and boost the plant growth quantity at different levels.These results also show the NtFer1 from tobacco possesses the ability of cleaning up reactive oxygen and the function of resisting several metal pollution more than those of non-transformant.Employing Agrobacteria-mediated leaf disc transformation method,the gene encoding tobacco ferritin(NtFer1) was introduced into the genome of Populus,and the Kanamycin tolerance,PCR-southern and Northern hybridization analysis indicated that exogenous gene ferritin gene correctly over-expressed.The heavy metal uptake in plant is a hot topic in the research field of environmental pollution,phytoremediation is a treatment technique by using plants to clean up heavy metal in soil.In the industry manufacture,the materials always are some different heavy metals,that results the pollution of soil and water in one region rarely worked by single metal.In this view,using genetic engineer to improve plant physiological performance to different heavy metal pollutants,developing transformants that can resist or enrich several different heavy metal pollutants at the same time holds a more significant sense and a more hopeful prospect in phytoremediation.