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

Ecology and ecosystem, Ecology and Ecosystem The concepts of environme...

Ecology and Ecosystem The concepts of environment, ecology, ecosystem, energy flow and nutrient cycling in the foundation course on Science and Technology. As you are aware ec

Inhibition might contribute to tumor formation, We now understand that muta...

We now understand that mutations that cause the inhibition of apoptosis are found in tumors. Because proliferation itself is not induced by the inhibition of apoptosis, explain how

Amoebas, two types of amoebas waste and how they get rid of them

two types of amoebas waste and how they get rid of them

Agama lizard, excretory system in agama lizard

excretory system in agama lizard

Codominance, explain the genotypes for each blood type and how this is an e...

explain the genotypes for each blood type and how this is an example of codominance. Blood type- A, AB, B, 0

Euthenics, Euthenics : It is the study of improvement of human races by pro...

Euthenics : It is the study of improvement of human races by providing better conditions. Euthenics means human improvement by altering external factors like as education or the co

What is the nitrogen cycle, What is the nitrogen cycle? The nitrogen cy...

What is the nitrogen cycle? The nitrogen cycle represents the circulation and recycling of the chemical element nitrogen in nature. The nitrogen cycle basically depends on t

Explain food applications of pullulan, Explain Food Applications of pullula...

Explain Food Applications of pullulan The food applications of pullulan include:  Due to its oxygen barrier properties, it can be used as a packaging material for fat /

Substances that have to be excreted from the body, Name four substances tha...

Name four substances that have to be excreted from the body. Substances that have to be excreted from the body are:- A) Carbon dioxide, B) urea, C) uric acid, D) 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