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

Illustrate the term cilia, Illustrate the term Cilia? A cellular hairli...

Illustrate the term Cilia? A cellular hairlike locomotory structure which comprises an extension of the plasma membrane surrounding a 9+2 organization of microtubules. Unlike f

Canine distemper, Canine distemper Canine distemper, a highly contagio...

Canine distemper Canine distemper, a highly contagious disease of dogs, is caused primarily by air- borne virus which belongs to the genus Morbillivirus in family Paramyxoviri

Bacterial diseases-black disease, Black disease It is a fatal peracute...

Black disease It is a fatal peracute disease caused by Clostridium novyi Type B. It is associated with liver damage caused by liver fluke. The onset of the disease is rapid fo

Wet stigma - category of stigma, Wet Stigma - Category of Stigma Petun...

Wet Stigma - Category of Stigma Petunia shows several randomly distributed 2-celled papillae on its surface. In a developing stigma, the epidermis is covered by a continuous,

What is the inner life of the genome, For the article entitled "The inner l...

For the article entitled "The inner life of the genome" which of the following is true? A. Individual chromosomes occupy explained territories within the nucleus. B. The spe

Direct vs. indirect competition model, Pikas (component 1), also known as "...

Pikas (component 1), also known as "rock rabbits" or "coneys", are small relatives of rabbits belonging to the genus Ochotona. The 30 species in this genus are confined to high alt

Plant, how to test for water in a leaf?

how to test for water in a leaf?

Living beings are made of organic and inorganic substances, Living beings a...

Living beings are made of organic and inorganic substances. According to the complexity of their molecules how can each of those substances be classified? Inorganic substances

Describe in detail about the huntington''s disease, Describe in detail abou...

Describe in detail about the Huntington's disease The brain of a person who has died as a result of Huntington's disease or Alzheimer's disease will look abnormal even to the

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