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

Explain dna binding domains, Helix-turn-helix This  motif  have  of  tw...

Helix-turn-helix This  motif  have  of  two    -helices  divided  by  a  short  (four-amino   acid) peptide  sequence  which  forms  a   -turn that shown in above figure.  When

Explain about the term- therapeutic, Explain about the term- Therapeutic ...

Explain about the term- Therapeutic Therapeutic approaches that scientists are pursuing include transplanting cells to replace those which are damaged or using growth factors

Gastric mucosa protected from the acid ph of the stomach, Q. How is the gas...

Q. How is the gastric mucosa protected from the acid pH of the stomach? The gastric epithelium is mucus secretory that is it produces mucus, the mucus covers the stomach wall p

Transport into the cytosol, Fatty  acids  are  synthesized  in  the  cytoso...

Fatty  acids  are  synthesized  in  the  cytosol,  but  acetyl  CoA  is  produce  from pyruvate in the mitochondria. Therefore the acetyl CoA must be transferred  from  the mitocho

An a=t mispairing leads to an a=c substitution, An A=T mispairing leads to ...

An A=T mispairing leads to an A=C substitution. The other DNA helix will contain a(n) __ pair. a. A=C b. A=T c. G=C d. B=Q e. T=T Can you also explain it please so if I'm ask

Determine regulation of ph of body fluids, Blood functions to maintain home...

Blood functions to maintain homeostasis in the human body through all but which of the following: Answer moving carbon dioxide away from cells following completion of aerobic metab

Define about the simple proteins, Define about the Simple proteins? Sim...

Define about the Simple proteins? Simple proteins are those which contain only amino acids or their derivatives and no prosthetic group. They yield only amino acids or their de

Importance of the brain evolved from fishes to reptiles, How has the import...

How has the importance of the brain evolved from fishes to reptiles? From the least to the most difficult brain structure, it is evident that the brain, from fishes to beings o

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