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

Agro industrial-evaluation of feedstuff, Evaluation of feedstuff In th...

Evaluation of feedstuff In the feed manufacturing process evaluation of the feed ingredients is very important in achieving consistent quality throughout the year. If one is a

Discuss various methods of dry heat sterilization, Question 1 List the dif...

Question 1 List the differential staining techniques used in microbiology laboratory. Explain Gram staining technique in detail. Add a note on modifications of Gram staining and a

Explain the obligatory losses of nutrients, Explain the Obligatory Losses o...

Explain the Obligatory Losses of Nutrients? Obligatory losses of nutrient are defined as 'the losses that occur when an individual is put on a diet free of that nutrient'. For

Multiple membrane-spanning proteins, Various integral proteins have multipl...

Various integral proteins have multiple membrane-spanning   -helices. Bacteriorhodopsin, a protein found in a photosynthetic bacterium captures the energy from light and uses it to

Define bioinert materials, Q. Define Bioinert materials? Bioinert mater...

Q. Define Bioinert materials? Bioinert materials are chemically inert in the body and exhibit minimal chemical interaction with adjacent tissue such as titanium and alumina (Al

How the arrangement of cells helps with tissue functioning, PROVIDE a speci...

PROVIDE a specific example for epithelial and connective tissues, how the arrangement of cells helps with tissue functioning?

Determine the self-monitoring of blood glucose, Self-Monitoring of Blood Gl...

Self-Monitoring of Blood Glucose (SMBG) In SMBG, patients measure and monitor their blood sugar level by themselves and assess their condition and know the response to the trea

Rash, Rash   Diseases such as Lyme disease and SLE which present with r...

Rash   Diseases such as Lyme disease and SLE which present with rash may be mistaken for ARF. Lyme disease presents with characteristic rash and arthritis (which appears 1 to 2

What are cytoplasmic inclusions, Cytoplasmic inclusions are cytoplasmic mol...

Cytoplasmic inclusions are cytoplasmic molecular aggregates, like as pigments, organic polymers and crystals. They are not considered cell organelles. Fat drops and glycogen gra

What is digital periapical radiography, Q. What is Digital periapical radio...

Q. What is Digital periapical radiography? Digital radiographs can be subjected to image processing with which the images can be altered to achieve task specific image characte

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