Evaluation of glufosinate gene transfer to safflower (Carthamus tinctorius L.) through floral dipping in Agrobacterium suspension

Among Iran's climate-well-adapted oily plants, safflower (Carthamus tinctorius L.) is considered as a top-ranked plant since it is well-adapted to areas with water shortage. Safflower is known as a model crop with a variety of fatty acids with a relatively high tolerance to salinity and drought, and also due to its high nutritional value that is related to the composition of 90 percent unsaturated fatty acids in its oil content. It has always been considered as a desirable and valuable oilseed plant and can play an important role in expanding the area under planting of oilseeds in the country. Although, Iran with its diverse climate, is one of the richest regions in the world in terms of safflower genetic resources, safflower planting is not very common in our country. One of the main reasons is probably the lack of promotion and low grain yield of its cultivars. In this study, For the first time the floral dipping was performed in Agrobacterium suspension in order that the glufosinate gene would be transferred to the safflower plant. Actually, the access to appropriate engineered cultivars will play a critical role in the development of safflower planting.  

Nine safflower lines were selected from a world-wide collection genotypes based on the different agronomic and phenotypic traits. They were submerged in Agrobacterium suspensions with optical density (OD600 nm) of 1 and in the presence of two different amounts of silwet-77.  

The genomic analysis of T1 generations using glufosinate resistance gene primers indicated the success of glufosinate transfer in safflower plant through flower immersion.  

Among 9 studied genotypes and 17 transformed plants using the floral dipping method, 3 transgenic plants were obtained with sequencing confirmation: one seedling belongs to Mahali Yazd genotype, one seedling belongs to the Mahali Kerman and one seedling belongs to the Paeize 12 genotype. All transgenic plants were inoculated with 40μl concentration of silwet-77.