Wednesday, September 17, 2008

History of Tissue Culture Techniques


History of Tissue Culture Techniques - The in vitro techniques were developed initially to demonstrate the totipotency of plant cells predicted by Haberlandt in 1902. Totipotency is the ability of a plant cell to perform all the functions of development, which are characteristic of zygote, i.e., ability to develop into a complete plant. In 1902, Haberlandt reported culture of isolated single palisade cells from leaves in Knop's salt solution enriched with sucrose.
The cells remained alive for up to 1 month, increased in size, accumulated starch but failed to divide. Efforts to demonstrate totipotency led to the development of techniques for cultivation of plant cells under defined conditions.
This was made possible by the brilliant contributions from RJ. Gautheret in France and P.R. White in U.S.A. during the third and the fourth decades of 20th century. Most of the modern tissue culture media derive from the work of Skoog and coworkers during 1950s and 1960s.

The first embryo culture, although crude, was done by Hanning in 1904; he cultured nearly mature embryos of certain crucifers and grew them to maturity. The technique was utilised by Laibach in 1925 to recover hybrid progeny from an interspecific cross in Linum. Subsequently, contributions from several workers led to the refinement of this technigue.
Haploid plants from pollen grains were first produced by Maheshwari and Guha in 1964 by culturing anthers of Datura. This marked the beginning of anther culture or pollen culture for the production of haploid plants.


The technique was further developed by many workers, more notably by JP. Nitch, C. Nitch and coworkers. These workers showed that isolated microspores of tobacco produce complete plants.
Plant protoplasts are naked cells from which cell wall has been removed. In 1960, Cocking produced large quantities of protoplasts by using cell wall degrading enzymes.
The techniques of protoplast production have now been considerably refined. It is now possible to regenerate whole plants from protoplasts and also to fuse protoplasts of different plant species. In 1972, Carlson and coworkers produced the first somatic hybrid plant by fusing the protoplasts of Nicotiana glauca and N. langsdorfii. Since then many divergent somatic hybrids have been produced.


A successful establishment of callus cultures depended on the discovery during mid-thirties of IAA (idole-3-acetic acid), the endogenous auxin, and of the role of B vitamins in plant growth and in root cultures.
The first continuously growing callus cultures were established from cambium tissue in 1939 independently by Gautheret, White and Nobecourt. The subsequent discovery of kinetin by Miller and coworkers in 1955 enabled the initiation of callus cultures from differentiated tissues. Shoot bud differentiation from tobacco pith tissues cultured in vitro was reported by Skoog in 1944, and in 1957 Skoog and Miller proposed that root-shoot differentiation in this system was regulated by auxin-cytokinin ratio.
The first plant from a mature plant cell was regenerated by Braun in 1959. Development of somatic embryos was first reported in 1958- 1959 from carrot tissues independently by Reinert and Steward.
Thus within a brief period, the tissue culture techniques have made a great progress. From the sole objective of demonstrating the totipotency of differentiated plant -cells, the technique now finds application in both basic and applied researches in a number of-fields of enquiry.

No comments: