Factors Affecting Transformation Efficiency of Poplar Hybrid Line NC5331 by Agrobacterium tumefaciens

Acetosyringone, pH, and glucose, which may affect Agrobacterium-mediated gene transformation to poplar hybrid line NC5331, were investigated in an attempt to raise the gene transfer efficiency. The Agrobacterium tumefaciens strain used harbored disarmed vector (pMON9749) carrying a bet-glucuronidase gene and a kanamycin resistant marker. With the addition of acetosyringone at 25 to 75 MuM, the transformation efficiency was significantly enhanced, but dependent on pH. Acetosyringone required a pH above 5.8 to achieve an efficient gene transfer and failed to enhance the transformation at lower pH. However, with addition of both acetosyringone and glucose, the transformation was not affected by pH. We conclude that optimizing transformation conditions may be very critical for a specific plant species and/or the Agrobacterium strain.