Efficient floral dip transformation method using on Cav.

Yellow cosmos ( Cav.) is a specific flowering plant and considered a suitable genetic engineering model. -mediated plant transformation is commonly used for plant genetic engineering. Floral dip transformation is one of the plant genetic transformation methods, and it involves dipping flower buds into an suspension. Studies on floral dip transformation of yellow cosmos have never been reported. Therefore, an efficient method in plant genetic engineering must be established. This study developed an effective and efficient floral dip transformation method for yellow cosmos. In this study, flower buds with sizes of 5-7 mm were used. Several parameters have been observed to optimize the floral dip method. These parameters included the optical density (OD) of culture, concentration of surfactant, and duration of flower bud dipping into the suspension. The results showed that the floral dip method was most efficient when the flower buds were dipped into suspension with OD = 0.8 and containing 5% sucrose and 0.1% Silwet L-77 for 30 s. This method enhanced the transformation efficiency at a rate of 12.78 ± 1.53%. The II and green fluorescent protein genes with sizes of 550 and 736 bp, respectively, were confirmed by polymerase chain reaction. In addition, the transgenic plants were kanamycin resistant and fluorescent under ultraviolet light observation. This finding suggests that the proposed floral dip transformation provides new insights into efficient plant genetic engineering methods for yellow cosmos.