Transgenic European aspen plants (Populus tremula L.) expressing the bar gene for phosphinothricin resistance have been produced using Agrobacterium tumefaciens-mediated transformation. 
Agrobacterium tumefaciens
Successful genetic transformation was confirmed by PCR analysis for thirteen lines derived from two elite genotypes.  Stable expression of the bar gene after overwintering outdoors was confirmed by RT-PCR. 
PCR
Stable expression of the bar gene after overwintering outdoors was confirmed by RT-PCR. 
RT-PCR