The application of an Agrobacterium-mediated in planta transformation system in a Catharanthus roseus medicinal plant

The lack of an efficient protocol for the transformation of Catharanthus roseus, as an important medicinal plant, causes obstacles in the genetic engineering programmes of this plant. Therefore, the present study was conducted to examine a convenient and reliable system for generating stable transgenic lines based on the in planta method. To do so, two different in planta Agrobacterium infection systems were investigated. The transgenic lines were produced through ovary injection and shoot apical meristem (SAM) immersing methods. The presence and expression of the GFP transgene in the T0 and T1 lines were confirmed by PCR and RT-PCR. Moreover, the ELISA test confirmed the GFP expression in the transgenic lines. Apart from the superiority of the ovary injection over the SAM inoculation due to the normal growth and healthy appearance, it also showed a significant difference from the point of the confirmed transgenic plant numbers. GFP integration was confirmed in 6 out of 50 T1 plants from the ovary injection and only 3 out of 150 plants generated from the SAM inoculation. In addition to the comparison of these two separate methods, we reached a new convenient in planta system by a 12% transformation rate for generating the C. roseus transgenic lines. According to the result of this study, ovary injection can be introduced as a novel, facile, and stable method for the Catharanthus transformation programme.