Establishing one-step hairy root transformation system in safflower using RUBY reporter

Safflower (Carthamus tinctorius L.) is an important economic crop, which has widespread applications in medicine, food, and industry. Currently, the study of gene function regulating the synthesis of key medicinal components in safflower has always been a research hotspot. However, due to the fact that the tissue culture method is time-intensive and heavily genotype-dependent, the pollen tube pathway method has low repeatability, high environmental sensitivity, and significant differences in evolutionary pathways and genetic backgrounds between model plants and safflower, and there are still many genes whose functions are unknown. In this study, a one-step hairy root transformation system in safflower was established, and the RUBY reporter was used to observe the transformation efficiency in real time. The explants and dark culture time were optimized, and the transformation efficiency reached 76.66 %. Moreover, this study provides a technical path for improving the genetic transformation of other medicinal plants.