Optimization of parameters to improve transformation efficiency of elephant foot yam (Amorphophallus paeoniifolius (Dennst.) Nicolson.

Elephant foot yam (Amorphophallus paeoniifolius (Dennst.) Nicolson), is an important edible tropical tuber crop, belonging to the family Araceae. Corms produced by this plant is very big and they are rich in starch, protein, mineral, vitamins, and dietary fiber but has acridity problem. This crop is susceptible to virus and phytoplasma diseases which affects crop growth and corm yield. Even though this crop has high commercial value, the problems like susceptibility to viral diseases, acridity problems, and lack of genetic diversity made hindrance in their exploitation. These issues can be resolved only by improving the characters through genetic transformation. To achieve genetic transformation in this important crop, a study was conducted to optimize various parameters for efficient Agrobacterium-mediated genetic transformation using embryogenic calli with vectors having gus reporter gene. Calli were developed using petiole and leaves of in vitro plantlets of elephant foot yam cultivar Gajendra and experiments were conducted to evaluate the sensitivity of calli to different doses of antibiotics viz. geneticin, hygromycin, ticarcillin. It was observed that complete death and discoloration of the calli were obtained with 25 mgl-1 geneticin and 10 mgl-1 hygromycin. The lowest lethal concentration of ticarcillin against Agrobacterium growth was found to be 500 mgl-1 which did not affect calli growth. Optimized parameters for efficient transformation in elephant foot yam include 100 μM acetosyringone concentration with 2 days of co-cultivation at temperature 22 °C using LBA4404 strain. The putative transformants were characterized for the integration of the gus gene using PCR and nucleic acid spot hybridization. The optimized protocol is simple and reproducible and may be adapted for other cultivars also. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13205-021-02824-6. © King Abdulaziz City for Science and Technology 2021.