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

Division phase or mitosis, DIVISION PHASE OR MITOSIS (M- PHASE) Cell di...

DIVISION PHASE OR MITOSIS (M- PHASE) Cell division was first  observed by  Naegeli 1842 in plant cells ,but  thoroughly described by Eduard strasburger  1875. Fleming 1879 desc

Explain the function of the pupil and of the iris, Q. What is the function ...

Q. What is the function of the pupil and of the iris? The iris works like the diaphragm of a photographic camera since it has muscles that relax or contract varying the pupil d

What is the physiological explanation for the daltonism, What is the type o...

What is the type of genetic inheritance of daltonism? Is daltonism more frequent in men or in women? What is the physiological explanation for the daltonism ? The Daltonism

Parazoans and simplest metazoans, in what aspect are the cnidarians simila...

in what aspect are the cnidarians similar to the protozoans?

Define food components other than essential nutrients, Define Food Componen...

Define Food Components Other Than Essential Nutrients? In the previous units so far, we have read about the six major nutrients, which are essential for us. Though these vary i

Crisis due to deforestation, Crisis due to Deforestation Due to conti...

Crisis due to Deforestation Due to continuing deforestation we are faced with a major ecological and socio-economic crisis. To reverse this trend of deforestation a National

What are nadph and nadp, Q. What are NADPH and NADP? NADP is the short ...

Q. What are NADPH and NADP? NADP is the short form of the nicotinamide adenine dinucleotide phosphate cation, a hydrogen acceptor. NADPH is made when NADP binds to one hydrogen

Which does not contain a guanidinium group, Which of the following does NOT...

Which of the following does NOT contain a guanidinium group Select one: a. Urea b. arginine c. creatine d. guanidinium ion

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