Transformation of Recalcitrant Sorghum Varieties Facilitated by Baby Boom and Wuschel2

Abstract Most reliable transformation protocols for cereal crops, including sorghum ( Sorghum bicolor L. Moench), rely on the use of immature embryo explants to generate embryogenic callus cells that are then transformed using Agrobacterium ‐ or particle‐bombardment‐mediated DNA delivery. Subsequent to DNA transfer, most protocols rely on selectable markers for the recovery of stably transformed callus that is then regenerated to produce T 0 plants. However, these protocols require specific genotypes that are innately capable of efficient embryogenic callus initiation. Here, we describe a system that makes use of the differential expression of the morphogenic regulators Baby Boom ( Bbm ) and Wuschel2 ( Wus2 ) to achieve transformation in varieties of sorghum typically recalcitrant to standard transformation methods. © 2018 by John Wiley & Sons, Inc.