Development of high-throughput tissue culture-free plant transformation systems

Efficient transformation systems are highly desirable for plant genetic research and biotechnology product development efforts. Tissue culture-free transformation (TCFT) and minimal tissue culture transformation (MTCT) systems have great potential in addressing genotype-dependency challenge, shortening transformation timeline, and improving operational efficiency by greatly reducing personnel and supply costs. The development of Arabidopsis floral dip transformation method almost 3 decades ago has greatly expedited plant genomic research. However, development of efficient TCFT or MTCT systems in non-Brassica species had limited success until recently despite the demonstration of successful in planta transformation in many plant species. In the last few years, there have been some major advances in the development of such systems in several crops using novel approaches. This article will review these new advances and discuss potential areas for further development.