Efficient and rapid method for the screening of transgenic rice plants

Abstract

Rice is one of the most important cereals crops with great potential for improvement through biotechnological intervention. Agrobacterium-mediated transformation method for rice has been well established. In the transformation method, antibiotic resistant gene of hpt is routinely used as a powerful marker for transgenic rice plants selection. In this study, the hygromycin sensitivity test was executed on wild type Pusa Sugandh 2 (PS2) seeds, based on mesocotyl length, root development and leaf color, the most efficient optimal concentration of hygromycin 50mg/L was used for selection of the transgenic seeds and leaf assay. Wild type seedlings revealed reduction in mesocotyls lengths, root elongation and bleached leaf, as compared to transgenic seedlings on hygromycin selection media. Non-transgenic rice leaves (PS2) had phenotypic symptoms of necrosis, dark-brownish strips or bleached tips and entirely bleach out of lamina, while transgenic leaf remained green and healthy after one week of hygromycin selection. Based on the above results, a simple, rapid, inexpensive, time-saving method for effective evaluation of transgenic progeny containing hpt gene using leaf and germination assay of transformed seeds are described. This study confirms an unambiguous differentiation between transgenic and non-transgenic plants.