Development of a simple and efficient method for Agrobacterium-mediated transformation in sorghum

Abstract

Sorghum is considered a recalcitrant crop based on genetic transformation. The main technical problem is callus browning in culture tissue and genetic transformation for sorghum. In this study, we developed a simple and effective method for sorghum transformation excluding tissue culture process. Sorghum mature embryos were pierced by a needle and then soaked in an Agrobacterium inoculum with acetosyringone. The best-performing concentration of acetosyringone was 100 μM in inoculation with pierced seeds. When these inoculated seeds grew to three leaves, a 1‰ hygromycin solution was used to brush the second and third leaf of inoculated seedlings to identify transformants. The identification results showed that the highest efficiency of transformation was 4% in the study. Molecular analysis for T0 and T1 plants identified that target gene was integrated into sorghum genomic DNA. And target gene can normally express in transformants' leaves. Genetic analysis of T1 transformants showed that most of T1 transformants fitted to 3:1 Mendelian inheritance. All these results showed that the presented method is an easy and successful method for sorghum transformation. In the future, the method will be used for broad functional genomics studies and for biotechnological application of sorghum.