Question

The natural plant hormone isolated from corn kernels and coconut milk is
(a) Florigen
(b) ${ GA }_{ 3 }$
(c) Free auxins
(d) Zeatin
(e) Indole acetic acid

Answer 1

It is an adenine-derived cytokinin that exists in the form of a cis- and trans-isomer and conjugates. It was found in immature kernels of the Zea genus of corn. This encourages the development of lateral buds and induces cell division to develop bushier plants when sprayed on meristems.

Complete answer:
Zeatin is a plant hormone called adenine, derived from the purine base. It belongs to the cytokinin family of plant growth hormones and was discovered in the Zea genus of immature corn kernels.
In several plant extracts, zeatin and its derivatives are present and are the active ingredient in coconut milk, which causes plant growth. Zeatin has many anti-aging effects on fibroblasts of human skin. By agonizing the mammalian receptor of adenosine A2A, zeatin riboside has an immunomodulatory effect.

Additional information: Significant quantities of ${ GA }_{ 3 }$ are made by plants in their natural state. The hormone can be industrially developed using microorganisms. Gibberellic acid is a simple gibberellin, a diterpene pentacyclic acid that promotes cell growth and elongation. It affects plant decomposition and, if used in small quantities, helps plants grow, but eventually, plants develop tolerance to it.
The hypothesized hormone- like molecule responsible for regulating and/or causing flowering in plants is Florigen (or flowering hormone).
Florigen is produced in the leaves and acts in the buds and rising tips shoot apical meristem. It is recognized that it is graft- transmissible, and also between species functions.
Auxins are a class of plant hormones with certain morphogen-like features (or plant- growth regulators) . In the coordination of several growths and behavioral processes in plant life cycles, auxins play a cardinal role and are important for the development of the plant body.
The most common naturally occurring plant hormone in the auxin class is indole-3-acetic acid. It is the most recognized of the auxins and has been the focus of extensive study by plant physiologists. IAA is an indole derivative which contains a carboxymethyl substituent.
So, the correct answer is ‘(d) Zeatin’.

Note: Zeatin has a number of consequences, such as:
- Promotes initiation of callus in conjunction with auxin, 1 ppm concentration.
- Supports the fruit collection. Zeatin 100 ppm + ${ GA }_{ 3 }$ 500 ppm + NAA 20 ppm, sprayed after flowering on the 10th, 25th, and 40th days.
- Vegetable Yellowing Retards, 20 ppm, sprayed.
- Auxiliary stems allow them to expand and bloom.
- To stimulate seed germination and seedling development, zeatin can also be added.