Explanation: The introduction of foreign DNA into a plant followed by stable transmission through the germline was first demonstrated in 1981.

Explanation: The first transgenic plant generated was that of tobacco. Soil bacterium was used as a vector for transferring exogenous DNA into the plant.

Explanation: Plant viruses have been developed as versatile episomal vectors, allowing high level transient gene expression.

Explanation: A fundamental difference between animals and plants is that organized, differentiated plant tissue shows a high degree of developmental plasticity.

Explanation: Seed derived callus tissue may be able to regenerate an entirely new plant under appropriate culture conditions. Depending on different species, different cultures can be obtained.

Explanation: For most plant species, some form of tissue culture step is therefore necessary for the successful production of transgenic plants.

Explanation: There is an increasing interest in the use of whole plant transformation strategies, in which the need for tissue culture is minimized or eliminated.

Explanation: Callus cultures are established under conditions that maintain cells in an undifferentiated state. Plant tissue culture is required for most procedures.

Explanation: Tissue culture is the process whereby small pieces of living tissue (explants) are isolated from an organism and grown aseptically.

Explanation: For successful plant tissue culture it is best to start with an explant rich in undetermined cells because such cells are capable of rapid proliferation.