Rejection reaction, Biology

Assignment Help:

Rejection Reaction

For rejection reaction the physiological and biochemical processes are set in the pistil by the recognition reaction specific to the type of pollen that lands on stigma. In contrast to systems where inhibition can occur on stigma itself thus preventing germination of pollen or its entry into style, in GSI system it may occur in style leading to either inhibition of pollen tube growth or its bursting.

The pollen wall and its protein content plays an important role in pollen stigma interaction. Through cytochemical studies it has been observed that the pollen wall is perforated by protoplasmic strands giving the appearance of a living physiological structure playing a very responsible role in the process of interchange between the pollen grain and the substrate. The incorporation of proteinaceous substances in the exine and the intine has been demonstrated by EM studies of the pollen wall during development. A good amount of mobile proteins of the pollen grains is S-gene specific. The recognition proteins of incompatibility are held extra-cellularly in the pollen wall. In GSI plants, these proteins are present in the intine while in SSI plants they occur in the exine.


Related Discussions:- Rejection reaction

Control of noise pollution, Following ways can be used for control of noise...

Following ways can be used for control of noise pollution: It can be controlled by designing, fabricating and using quiter machines. In heavy industries, sound proof insul

Adenosine diphosphate (adp), ADP is lower energy form of ATP, containing tw...

ADP is lower energy form of ATP, containing two (in spite of the three in ATP) phosphate groups attached to the adenine base and ribose sugar.

Explain glycogen storage diseases, Glycogen Storage Diseases Glycogen  ...

Glycogen Storage Diseases Glycogen  storage diseases are caused by  genetic defects that result  in  deficiencies in  certain enzymes of  glycogen metabolism. These deficiencie

Define conical flask - nutritional biochemistry, Define Conical Flask - Nut...

Define Conical Flask - Nutritional Biochemistry Conical flask is a piece of chemistry laboratory equipment, a container often made of glass, which has a narrow cylindrical mout

Pathphysiology of rheumatic fever, Pathphysiology Streptococcal upper ...

Pathphysiology Streptococcal upper respiratory infection leads to production of antibodies. An abnormal immunological response to the upper respiratory infection with Beta- h

What are the grasslands of north and south america, What are the grasslands...

What are the grasslands of North America and of South America respectively called? The steppe the grasslands of North America are called as prairies . The grasslands of South

Explain xanthan gum, Explain Xanthan Gum Xanthan gum is a microbial pol...

Explain Xanthan Gum Xanthan gum is a microbial polymer prepared commercially in pure culture fermentation from Xanthomonas campestris. This polysaccharide was given the generic

Explain about manual and automatic toothbrushes, Manual and Automatic Tooth...

Manual and Automatic Toothbrushes Brushing is imperative and soft or medium toothbrushes are recommended. Small heads are useful because they allow better access. Automatic too

Heroin (diacetylmorphine or diamorphine), HEROI N (DIACETYLMORPHINE OR DIA...

HEROI N (DIACETYLMORPHINE OR DIAMORPHINE) - Heroin is a white, crystalline semi synthetic compound prepared from morphine by acetylation. Most dangerous opiate. It i

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