Totipotency refers to a plant cell's genetic potential to regenerate an entire plant. In plant tissue culture, cells taken from plant parts can form an unorganized mass of cells called callus tissue when placed in a sterile nutrient medium. The cells within callus tissue are totipotent, meaning they have the ability to regenerate into a whole plant under the right conditions and hormone manipulations. Totipotency is important for plant science applications like vegetative propagation of crops, genetic modification of plants, and preservation of endangered plant species through long-term storage of totipotent cells.