Get The Effect Of Nitrogen On Callus Regeneration Form

Callus Induction by Plant Hormones. Auxin and cytokinin have been widely used to generate callus, but surprisingly little is known about how they induce callus at the molecular level. Several recent studies demonstrated that various regulators of lateral root development participate in callus formation on CIM.

Auxin is needed for callus induction to form explants. Auxin is very effective to initiate the cell division, cell elongation, development and growth (Gaspar et al. 1996; George 2008). The response of cell to auxin will enter the dedifferentiation stage, and then cells start to divide again (George 2008).

The plant hormones auxin and cytokinin are well established as efficient inducers of callus in tissue culture. Recent studies have revealed that callus formation on auxin-rich callus-inducing media (CIM) follows a developmental program of root formation.

After the callus has formed, the concentration of hormones in the medium may be altered to shift the development from callus to root formation, shoot growth or somatic embryogenesis. The callus tissues then undergo further cell growth and differentiation, forming the respective organ primordia.

The auxin-induced callus formation in plant in vitro regeneration represents a typical cell fate change where somatic cells are switched into pluripotent callus cells, which is, to some extent, analogous to the induction of pluripotent stem cells in animals.

Callus can be produced from a single differentiated cell, and many callus cells are totipotent, being able to regenerate the whole plant body (Steward et al., 1958; Nagata and Takebe, 1971).

Nitrogen is so vital because it is a major component of chlorophyll, the compound by which plants use sunlight energy to produce sugars from water and carbon dioxide (i.e., photosynthesis). It is also a major component of amino acids, the building blocks of proteins. Without proteins, plants wither and die.

Callus Induction by Plant Hormones. Auxin and cytokinin have been widely used to generate callus, but surprisingly little is known about how they induce callus at the molecular level.