What plant tissue culture is

Plant tissue culture means growing plant cells, tissues or organs on an artificial (synthetic) medium, in sterile (aseptic), carefully controlled conditions. It rests on totipotency: the ability of a single plant cell to divide, specialise and regenerate a whole plant.

The idea grew step by step:

• Schwann and Schleiden saw the cell as the basic unit of life.
• Gottlieb Haberlandt tried to grow specialised plant cells on nutrient media. He failed, but in 1902 he set down principles that were later proved right, so he is called the 'Father of Plant Tissue Culture'.
• Researchers found that vitamins and auxins were essential. Coconut water (Van Overbeek, 1941) helped young embryos grow. White made the first synthetic medium (1937).
• Skoog and Miller discovered the cytokinin kinetin (1955), and showed (1957) that the ratio of auxin to kinetin decides what forms: high auxin gives roots, high kinetin gives shoots, and an in-between ratio gives an unorganised mass, a callus.
• Murashige and Skoog made the MS medium (1962), still the most widely used today.
• In India, Guha and Maheshwari grew the first haploid plants of Datura from anthers (1964).

Later milestones: fusing protoplasts of Nicotiana (1972); the 'pomato' (1978); the term somaclonal variation (1981); making the dye-drug shikonin in cell culture; Bt cotton; Golden Rice; and the first plant-made enzyme medicine, for Gaucher's disease.