Iaa stimulates cell enlargement, Biology

Assignment Help:

IAA Stimulates Cell Enlargement

Cell wall contains layer of cellulose fibrils and are normally quite rigid. Thus for a cell to grow, there must be a mechanism for relaxing the cellulose fibrils. IAA releases the cross linking bands which hold the micro fibrils together. Auxin is thought to cause the walls to become plastic and them osmotic water intake causes the cell to swell like a balloon. American physiologist P.M. Ray has observed that IAA effect on elongation begins after a lag period of only 8-12 minutes, in tissues as coleoptiles. Recently it has been found that with certain auxins or even with IAA itself when used under correct conditions, the lag period can be reduced to 1 minute or less.

These effects are now considered to be as a result of activisation of proton pumps in membrane that pump protons in cell wall and cause a rise in acidity. Acidification loosens bonds in cell wall and cell wall plasticity increases. This rapid response is followed by activation of m-RNA translated into enzymes that catalyze synthesis of cellulose and other cell wall materials which cause the strengthening of elongated cell wall completing the cell elongation.


Related Discussions:- Iaa stimulates cell enlargement

What is the trace element, What is a trace element and how are they importa...

What is a trace element and how are they important in organisms, give an example.

Show geniculate bodies of the thalamus, Q Show Geniculate Bodies of the tha...

Q Show Geniculate Bodies of the thalamus? THALAMUS - two large circular shaped masses at "roof" of 3rd brain ventricle. Contains many different nuclei which function as relay

Explain working of cerebral cortex, Q. Explain working of Cerebral Cortex? ...

Q. Explain working of Cerebral Cortex? Cerebral Cortex/Cerebrum: The cerebrum or the cortex is the large part of the brain and is associated with the cognitive functions of the

Chordates and non chordates, give an account of ciliary and flagellar move...

give an account of ciliary and flagellar movement in protozoa

Explain acute renal failure, Explain Acute Renal failure Acute Renal f...

Explain Acute Renal failure Acute Renal failure:  Renal failure associated with burns or other trauma or with sharp infection or obstruction of the urinary tract.

Bacterial and mycotic diseases, Bacterial and Mycotic Diseases Bacteria...

Bacterial and Mycotic Diseases Bacteria and fungi are microscopic organisms which are ubiquitous in nature and are widely present in soil, fresh and salt water, air, vegetation

Function of noradrenaline in consciousness, Q. Function of Noradrenaline in...

Q. Function of Noradrenaline in consciousness? Increased level of noradrenalin is implicated in wakefulness. Locus coeruleus noradrenergic neurons decrease their rate of firing

How is the structure of a mitochondrion well adapted, How is the structure ...

How is the structure of a mitochondrion well adapted for the activities it carries out? The mitochondrial membranes segregate the enzymes and reactants of the Krebs cycle, faci

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd