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

Set them up using the punnett square, Two gene loci, A and B, assort indepe...

Two gene loci, A and B, assort independently, and alleles A and B are dominant over alleles a and b. Indicate the probability of producing: An aB phenotype from a cross AaBb x AaBB

What is the tertiary structure of a protein, What is the tertiary structure...

What is the tertiary structure of a protein? What are the main kinds of tertiary structure? The tertiary protein structure is a spatial conformation additional to the secondary

What are some of the possible treatments, My friend was injured several yea...

My friend was injured several years ago in a car accident and she was diagnosed with a herniated disc. Can you please explain using the correct anatomical terminology what herniati

Amphibian circulation be classified as incomplete and double, Q. Why can th...

Q. Why can the amphibian circulation be classified as incomplete and double? The amphibian circulation is double because it is composed of pulmonary and systemic circulations r

Binomial nomenclature, collection of different animals,human being and inse...

collection of different animals,human being and insects stages of binomial nomenclature

Liquid fuels, Petroleum Liquid fuels are widely used for industrial and...

Petroleum Liquid fuels are widely used for industrial and domestic purposes. Almost all internal combustion engines run on liquid fuels. Liquid fuels are also used in heat gene

Write two functions of proteins in biological system, Write two functions o...

Write two functions of proteins in biological systems. The important functions of proteins in biological systems are as follows: enzymes membrane carriers anti

Frog, Frog fema reproductive system

Frog fema reproductive system

Objectives of the nutritional care process, Thus, the objectives of the nut...

Thus, the objectives of the nutritional care process should include the following points: 1. Restoration of good nutritional status with dietary modifications and counseling.

Splenic abscess, Splenic infarction is a common complication of left-sided ...

Splenic infarction is a common complication of left-sided IE (40 per cent of cases). Only 5 per cent of patients with splenic infarction will develop splenic abscess. This infectio

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