Explant position effect on gene transformation to flax (Linum usitatissimum L.) via Agrobacterium tumefaciens

Background and purpose: In this study, it was aimed to determine the influence of the position where explant was taken, on gene transfer via Agrobacterium tumefaciens-mediated transformation in flax (Linum usitatissimum L.). Materials and methods: In the study, three different hypocotyl explants, 0.5 cm long, were used according to the position where they were isolated from. Seven-day-old sterile seedlings having cotyledon leaves and no root system were inoculated with bacterial solution for 20 min. GV2260 line of Agrobacterium tumefaciens having ‘pBIN 19’ plasmid containing npt II gene and GUS reporter gene, was used in transformation studies. After inoculation, hypocotyl section of the seedlings was divided into 3 parts labeled with number 1 (part above the root), number 2 (part above number 1) and number 3 (part below cotyledon leaves) and these parts were left to co-cultivation for 2 days. Then, hypocotyl segments were transferred to selection medium containing antibiotics. The presence of npt-II (neomycin phosphotransferase II) gene in transformants was confirmed by PCR analysis. Results: It was observed that the highest transgenic plant number was obtained from the explants taken from the region labeled 1, which was followed by explants taken from the region labeled 2. No transgenic plants could be obtained from explants isolated from region labeled 3. Conclusions: This study showed that not only explant type but also the position explant was excised from is very important in gene transfer via Agrobacterium tumefaciens.