Optimization of Transformation Conditions in Maize Inbred Line Calli via Agrobacterium tumefaciens

Embryogenic calli of elite maize inbred lines Ye515 and Ye502 were transformed by mediation with Agrobacterium tumefaciens , and fertile plantlets were regenerated from the transformed calli. In the process of Agrobacterium infection, vacuum infiltration, partial enzymolysis and sonication could improve transformation efficiency significantly. During Agrobacterium infection, by vacuum infiltration at 50 kPa for 5 min, transformation efficiency of embryogenic calli of Ye515 and Ye502 increased from 6.3% and 4.5% to 8.7% and 7.8%, respectively (Fig.3). Partial enzymolysis of calli with 0.2% Macerozyme R 10 for 10 min before infection improved transformation efficiency of Ye515 and Ye502 to 8.3% and 8.9% (Fig.4). After sonication for 90-120 s at 100 W during infection, transformation efficiency of embryogenic calli was up to 9.1% and 9.4% for Ye515 and Ye502, respectively (Fig.5).