Question

Bring out the physiological effects of cytokinin.

Answer 1

Hint: Plants also have hormones as humans that help them in their growth and development. Some will enhance/trigger shoot growth or root growth, while some inhibit them. Some of them are also used in plant tissue culture.

Complete answer:
The various plant hormones are auxins, cytokinins, gibberellins, abscisic acid, ethylene, etc. They all perform different functions and promote or inhibit growth.
Auxin is the plant growth hormone. It affects the elongation in shoots. They will majorly help only stem tips. Cytokinin helps in cell growth in the apical region and leaf senescence. Physiological effects are the one which is visible from outside with naked eyes that means changes in the physiology of the plant.
Some of the physiological effects of cytokinin are as follows:
i. They promote cell division.
ii. They initiate bud and root formation with the help of auxin.
iii. They promote lateral budding in specific mediums.
iv. It can delay the process of ageing in plants.
v. It promotes germination.
vi. It breaks the dormancy of seeds.
vii. They promote embryogenesis and maintenance of roots, and shoot meristems.
viii. Examples of cytokinins are – kinetin, benzyl adenine etc.
ix. Zeatin is natural cytokinin obtained from corn. They are also found in fungi, bacteria etc.

Note: Plant hormones have a major effect on the morphological features of plants rather than just shooting or rooting. IAA being the natural auxin is present in abundance in plants, but NAA is the synthetically made auxin in the labs, which is similar to the IAA. The anti-auxin used is PCIB (p-chlorophenoxy isobutyric acid). Abscisic acid is the inhibiting plant hormone which inhibits cell growth and differentiation.