The introduction of t-DNA into plants involves :
Altering the pH of the soil, then heat-shocking the plants
Exposing the plants to cold for a brief period
Allowing the plant roots to stand in water
Infection of the plant by Agrobacterium tumefaciens
By introducing t-DNA in plants, infection of the plant takes place by Agrobacterium tumefaciens. Other factors such as water, cold, and pH do not affect t-DNA.