Transgenic Alfalfa And Their Capacity To Heavy Metals And Organic Pollutants

In China,kinds of pollution caused by rapid industrialization have brought outa lot of problems to serious soil environment.If we can not solve the problems ofpollution, the sustained development of economy will be comproised and ourhealth will be undermined by the toxic environment. So it seems that it is high time totake measures to control and restore the soil which is being polluted. Now, thegeneral soil remediation refers to the physical/chemical remediation andbioremediation. Phytoremediation has many advantages to the environment,forexample,fast, efficient, low cost, and it is friendly to soil. In recent years, the maketprospects of phytoremediation technology is promising and broad.This study aims to transduce the two genes into alfalfa by transgenictechnology,in order to enhance its ability to repair soil contaminated with heavymetals and organic compound; these two genes are valid for their different usage,MT10gene is effective for absorbing a variety of heavy metal metallothionein, NSFAgene is relating to degradation of organic compound. Currently, at home and abroad,there is no same report about this research about taking advantage of these two genesto restore the worsening soil.In this paper,Experimental plants contain NSFA gene construct binary expressionvector: the Gus gene in the vector PBI121was replaced by the exogenous geneconstruct P35S-NSFA-T35S expression cassettes which can expressed highly in thealfalfa. Then the expression vector pBI121-NSFA by freeze-thaw method togetherwith another plant expression vector pBI121-MT is transduced into the sameAgrobacterium tumefaciens LBA4404.In this experiment we selected " Algonquin ""Golden Queen""Victoria" threealfalfa, and ultimately we chose "Golden Queen" alfalfa’s hypocotyl as genetransformation receptor, investigated many factors such as sucrose,agar,different plant hormone，Anti-browning agents.And many tissue culture conditions were optimized toget higher yield of embryonic callus organization, and gradually got the best "GoldenQueen" genetic transformation regeneration system.Taking advantage ofAgrobacterium-mediate transformation MT10gene and NSFA gene were transformedinto the "Golden Queen" alfalfa. After co-cultivation, kanamycin-resistant transgenicplants240were obtained.After molecular level detection with the approaches of PCR and RT-PCR to the240selected resistant plants, resistant functions to the heavy metals and organiccompounds of the transgenic plants were identified.The obtained results showed thatresistant alfalfa plants integrated exogenous gene MT10and NSFA andexpressedeffectively.The seedings and mature plants obtaind were respectively moved to thematrix containing disodium chromate or TNT,and some matrix containing both.Ascontrol,the wild seedings and mature plants had the same treatment.From theresults,the alfalfa had composite gene were2-3times stonger than the wild type.