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

Genetics, polymorphism and its causes

polymorphism and its causes

What is intermediate acting insulin, Q. What is Intermediate acting insulin...

Q. What is Intermediate acting insulin? Intermediate acting: This type works more slowly than short acting. It works hardest 8-12 hours after injection and still keeps on worki

Nutrition education for prevention of vitamin a deficiency, Define Nutritio...

Define Nutrition Education for prevention of vitamin a deficiency? Ignorance, you may recall studying earlier, is an important determinant of vitamin A deficiency. There is, th

How to load glycogen, How to load glycogen? Over the past fifty years, ...

How to load glycogen? Over the past fifty years, the biggest breakthrough was the discovery of how to load glycogen and sophistication in the methods of glycogen loading. Nitro

Chlorofluorocarbons cause global problem, In what way do chlorofluorocarbon...

In what way do chlorofluorocarbons (CFCs) cause global problems? Chlorofluorocarbons react with and deplete the ozone in the ozone layer. This permits more ultra-violet light f

Air pollution, It is defined as the presence of chemicals and particulate i...

It is defined as the presence of chemicals and particulate in the atmosphere in quantities and pollution that are harmful to human health and environment. It occurs when the concen

Explain separation of homologous chromosomes, Q. What are the respective fu...

Q. What are the respective functions of the separation of homologous chromosomes and of the separation of alike chromatids in meiosis? The separation of homologous chromosomes

Describe the structure of lipoprotein, There are several different lipoprot...

There are several different lipoprotein species found in plasma but their basic structures are similar. The insoluble lipid (cholesterol ester and triglyceride) forms a central cor

According to their morphology how are bacteria classified, According to the...

According to their morphology how are bacteria classified? Bacteria present dissimilar morphological patterns. A bacterium can be classified into coccus, bacillus, vibrion or s

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