Scientists have successfully created transgenic forms of medicinal ajowan plant (Trachyspermum ammi) which are more resistant towards drought and salinity stress.
Interest in medicinal plants has grown significantly in past few years. Iran harbors a very diverse population of medicinal plants. Ajowan plant (Trachyspermum ammi) is one of the most valuable medicinal plants in Iran. Since this plant is sensitive to drought and salinity stress, scientists from Agricultural Biotechnology Research Institute of Iran(ABRII) and University of Tehran in collaboration with Palacky University in Czech Republic have used gene transfer to improve ajowan’s tolerance toward drought and salinity.
BADH Gene transfer
Scientists used Betaine Aldehyde Dehydrogenase(BADH) gene to enhance tolerance against drought and salinity. They used two methods to transfer the BADH gene into ajowan: tissue culture-based, and in planta Agrobacterium-mediated gene transformation. This was the first time that these two methods have been used for gene transfer in this medicinal plant. Scientists also investigated several parameters including Agrobacterium optical density (OD), Agrobacterium strain, Agrobacterium killing antibiotic, acetosyringone concentration, and inoculation duration. The selected antibiotic, Kanamycin, was applied to inhibit growth of non-transgenic cells. Researchers identified minimum inhibitory effect of Kanamycin on transgenic cells by testing different concentrations on hypocotyl segments. The pBI121 binary vector harboring kanamycin resistance gene and BADH gene in its T-DNA region was applied to transfer BADH gene. In both methods, scientists confirmed successful expression of transferred gene in ajowan plant using polymerase chain reaction (PCR) and reverse transcription polymerase chain reaction (RT-PCR) methods.
Improved tolerance in transformed ajowan
Researchers concluded that BADH gene transfer significantly enhanced ajowan’s tolerance against drought and salinity. They also showed that transformed ajowan plants had more thymol content compared to non-transformed plants under drought stress condition.
Meanwhile, researchers hope to use the same methods to assess and enhance the quality of other medicinal plants. They believe that biotechnology-based breeding methods have the potential to protect valuable industrial medicinal plants from danger of extinction and improve their properties.