*Correspondence: Jieting Xu (xjt@wimibio.com), Wenhao Yan (yanwenhao@mail.hzau.edu.cn)

Traditional genetic transformation of wheat relies on specific genotypes and immature embryo, which seriously impedes progress in wheat functional genome research. Recently, a class of morphogenic regulators (e.g., BABYBBOM, WUSCHEL2, GRF4/GIF1, WOX5, etc.) has been identified to improve the efficiency of genetic transformation of crops. We developed a wheat genetic transformation mythology to reduce the cycle of genetic transformation to 54 days.

A systematic comparison of the effects of multiple regeneration factors in wheat transformation revealed that the four regeneration factors, BBM/WUS & GRF-GIF, could achieve a transformation efficiency of up to 55.4% when co-transformed with the tested strains. In order to reduce the negative effect of regeneration factors, we compared the isolation efficiency of the latter when the test strain was co-transformed with BBM/WUS and GRF-GIF strains at 5:1 and 10:1 ratio, respectively, and found that the transformation efficiency was unaffected but the elimination efficiency was significantly increased to 95.5% with 10:1 ratio.

Meanwhile, visual isolation of regeneration factors could be achieved by expression pLTP2::DsRed cassettes with morphological regulators together. We tested the robustness of expressing the four morphogenic regulators simultaneously in multiple genotypes and the results all showed that this combination could greatly promote genetic transformation efficiency and editing efficiency in wheat.

Surprisingly, by combining the four morphogenic regulators, we succeeded in obtaining transgenic lines with approximately 13% efficiency with mature embryo from both Fielder and Kenong199 genotypes. This method greatly reduces cost and time needed for transformation in wheat.