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

Describe the patent ductus arteriosus, Describe the Patent Ductus Arteriosu...

Describe the Patent Ductus Arteriosus? It is the persistence of normal fetal channel connecting the aorta and pulmonary artery. It accounts for 5-10 per cent of all CHDs. Funct

What is rounded st depression, Q. What is Rounded ST Depression? A roun...

Q. What is Rounded ST Depression? A rounded ST-segment depression pattern in the CM5 lead, as well as in the other leads, is common and is often associated with ischaemia. This

How to removes hydrogen from fatty acids, Suppose you treated butter with a...

Suppose you treated butter with a fatty acid desaturase, an enzyme that removes hydrogen from fatty acids and creates double bonds. What would happen?

Etiology, Etiology: This is the study of origin of diseases. In other words...

Etiology: This is the study of origin of diseases. In other words we can say etiology is the study of causation and origination. Etiology most commonly used in philosophical theori

Define the carbohydrate and fat required for elderly, Define the Carbohydra...

Define the Carbohydrate and Fat required for elderly? Carbohydrate: It is usually recommended that approximately 55en% (percent of  energy) be provided from carbohydrate food

Explain the meaning of a repression lag, Which of the following most accura...

Which of the following most accurately explains the meaning of a repression lag? A. A repression lag refers to the time that it takes for the last full-length mRNA transcript t

Hydrocele, Hydrocele A hydrocele is a painless water-filled cyst found...

Hydrocele A hydrocele is a painless water-filled cyst found in front of the testis.It is brightly translucent and cannot be emptied by pressure of a 'flap valve' at its jun

genes occur on chromosome , In Drosophila, these genes occur on chromosome...

In Drosophila, these genes occur on chromosome 4. H - wild type (normal)     h - hairy F - wild type                   f - frizzled E - wild type                  e - vest

What is the heterotrophic hypothesis on the origin of life, What is the het...

What is the heterotrophic hypothesis on the origin of life? As per to the heterotrophic hypothesis the first living beings were very simple heterotrophic organisms that is not

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