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Detailed explanation-1: -Auxins are a powerful growth hormone produced naturally by plants. They are found in shoot and root tips and promote cell division, stem and root growth. They can also drastically affect plant orientation by promoting cell division to one side of the plant in response to sunlight and gravity.

Detailed explanation-2: -Auxin Autotrophy: The parental protoplast or cell requires an auxin compound in order to proliferate, whereas hybrid callus tissue needs no such requirement because the cells are auxin autotrophic. ADVERTISEMENTS: Therefore, somatic hybrid cells can be isolated selectively by growth on auxin-free culture medium.

Detailed explanation-3: -Two main types of synthetic plant growth regulators with auxin-like activity have been described: 1-naphthalacetic acid (NAA) and 2, 4-D-related compounds. Both compounds exert auxin-like influences, including root elongation inhibition and lateral root promotion (Fig.

Detailed explanation-4: -The most important naturally occurring auxin is ß-indolylacetic acid (IAA), which is formed either from the amino acid tryptophan or from the breakdown of carbohydrates known as glycosides. This hormone affects plants by its action on chemical bonds of carbohydrates comprising plant cell walls.