Plant Hormone 

in this blog we are discussing about the "Plant Harmon" like Auxin, Gibberellin, Cytokinin, Ethylene oxide, Abscisic acid and their function.

what is plant hormone?

 Also known as plant growth hormone.

Phyto hormones, growth bioregulators.

These are those chemical substance which are responsible for the growth of plant and also control, it's physiological process.

what are type of plant hormone?

Auxin, Gibberellin, Cytokinin - promoters (Induced plant growth).

Ethylene oxide, Abscisic acid - Inhibitors (Inhibit growth).

what is auxin? function of auxin.

Auxin - (Discovered by Charles Darwin).

Derived from a Greek word "auxin" which means to grow.

It is the major plant Hormone to be discovered.

* Functions- 

• Auxin enhanced cell elongation and stem elongation.
• It cause root formation, delaying leaf senescence, fruit ripening and used in embryogenesis.
• It promote xylem differentiation.
• Promote leaf growth, fruit growth etc.

Production:-

• It is made in actively growing tissue which includes young leaves, fruits and especially the shoot apex.
• Made in cytosol of cells.
• It has basipetal transport (towards the base), move from up to down.

Types:-

• Commonly used naturally (IAA) auxin is indole-3-acetic acid & indole-3-butyric acid (IBA).
• Commonly used synthetic auxin are 1-haphthalene acetic acid (NAA).

what is cytokinin? what is the function of cytokinin.

 Cytokinin's:- (Discovered by f. Skoog, [Miller in 1950s].

• Cyto - Cell + kinin - division.
• These are those plant Hormone which promote cell division.
• They contain purine ring in its structure.
• It has acropetal transport [toward the top].

Functions:- 

• Stimulation of cell division.
• Release and induced bud formation.
• Development of embryos during seed development.
• "[Cell division is regulated by the joint action of auxin and Cytokinin's].

Types & examples:-

Synthetic derived

a. Kinetin.

[Play the role in nucleic acid metabolism].

Naturally accruing Cytokinin's.

b. Zeatin [effect on leaf senescence].

Cytokinin's primarily synthesized in meristematic region of the roots and also produced in developing embryos.

what is Gibberellins? what is the function of Gibberellins.

Gibberellins:-

• They belong to the class of endogenous plant growth regulators.
• it is about 50 gibberellins at present in which accurse in green glands and other in some fungi.
• these are plant hormone that promote growth, seed germination and leaf expansions. 
• these are present in different types of organs and tissues such as roots, shoots, buds, leaves, root, huddles, fruits etc.
• transport across xylem, phloem, cell to cell or made in that tissue which it is used.
• GA3 is called as Gibberellic acid and used to increase the shoot elongation.
• Mechanism- GA3 induced activity of gluconeogenic enzyme- rapidly convert lipid to sucrose which further used in growth & development.

Functions- 

• It promote flowering, seed germination and stem elongation.
• Increase in the size of leaves and stem or shoot elongation.
• Rarely used compared to auxin and cytokinin.
• Able to produce morphological changes in plants.

what is the ethylene oxide? what are the function of ethylene oxide.

Ethylene oxide:- 

• it is a gaseous hormone synthesized in cultured cell, fungi, and bacteria 
• at higher concentration it inhibit growth of plant [Dcrease plant elongation] so also know as plant growth inhibitor hormone.

Synthesis:- 

• It is an simple organic molecules so synthesized from methionine & on large scale produced by incomplete burning of carbon rich substance like natural gas, coal & petroleum.

structure:-

Functions:-

• It promotes fruit ripening, senescence and leaf abscission.
• at low concentration sometimes it promote growth but at higher always inhibit growth.
• It can increase cell expansion.
• in 1934, gene reported that plant synthesize ethylene.

what is the abscisic acid? what are function of abscisic acid.

Abscisic acid (ABA):-

• A plant hormone which promote leaf detachment, induced seed and bud dormancy, and  inhibit germination.
• It is a natural plant growth inhibitor.
• ABA concentration are found to be enhance in stress condition like mineral deficiency, injury etc, so  also called as "stress hormone".
• it is naturally produced in plant tissue.
• In 1963, fredrick addicott isolate two compound ABSCISIN-1 & ABSCISIN-2.

Functions:-

• Closing of stomatal aperture & abscission of leaves.
• Control of water and ion uptake by roots.
• seed and bud dormancy.
• inhibit Auxin promoted cell walls acidification loosening and slow all elongation.