Function Identification And Genetic Transformation Of PtrAMT1;6,An Ammonium Transporter Of Populus Trichocarpa

Nitrogen is essential for the growth of trees species,it is the main constitution of organism. However, nitrogen in the soil is always insufficient to satisfy the needs of the strong growth of forestAnd because food security plays a decisive role in prosperity and stability of a country,better fertile soil is generally used for agricultural production, and plantations is often constructed in infertile areas.Unlike to crops, Plantations can not be fertilized regular.Therefore,it is a great significance to promote the trees grow in barren soil by improving the nitrogen absorption and utilization efficiency.Previous studies have shown that nitrogen has an important influence in wood quality.AMT is a important transporter in ammonium absorption and transfer,which has the function of ammonium absorption in root and ammonium retrieval in shootln our studies,we carry out the identification of expression patterns,function and genetic transformation as follows.(1) We performed real-time quantitative PCR reactions to analysis the relative expression of the gene in all tissues.As a result, PtrAMT1;6 is mainly expressed in the leaves and the expression levels is higher in mature leaves than the young; We detected the relative expression of PtrAMT1;6 in leaves under the effecting of the light-dark cycle.As a result, the expression levels of the gene was induced by darkness and suppressed by the dark.(2)We transformed the strain 31019b with the yeast expression vector pYES2 expressing PtrAMT1;6.The transformant was able to grow on medium containing≤1 mM NH4+ as the sole nitrogen source.(3)We transforted Arabidopsis thaliana(ColO) with the vector pCAMBIA 1301-PtrAMT1;6P. The transformant was able to be dyed blue by X-Gluc. That means the promoter of PtrAMT1;6 gene has the promoter activity.(4) We created PtrAMT1;6 overexpressing Arabidopsis lines to detect the function of the gene in Arabidopsis root.As a result, PtrAMT1;6 had no obvious function in root.(5)We created poplar 84K transgenic lines by the means of genetic transformation. By molecular verification,we detected thirteen overexpressing lines and five interferencing lines.These results suggest that,PtrAMT1;6 is likely to participate in ammonia reabsorption in shoot nitrogen metabolism.To further clarify this conclusion,we creat the overexpression and inhibition lines to lay the foundation of identify this conclusion and the function of PtrAMT1;6.