Novel Ternary Vectors for Efficient Sorghum Transformation.

Sorghum has been considered a recalcitrant crop for tissue culture and genetic transformation. A breakthrough in Agrobacterium-mediated sorghum transformation was achieved with the use of super-binary cointegrate vectors based on plasmid pSB1. However, even with pSB1, transformation capability was restricted to certain sorghum genotypes, excluding most of the important African sorghum varieties. We recently developed a ternary vector system incorporating the pVIR accessory plasmid. The ternary vector system not only doubled the transformation frequency (TF) in Tx430, but also extended the transformation capability into an important African sorghum elite variety.