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

Nutrition, define alimentary canal

define alimentary canal

Nitrogen fixation, Nitrogen Fixation As we have said before, atmospher...

Nitrogen Fixation As we have said before, atmospheric nitrogen cannot be used by plants or animals. It has to be first fixed. The term nitrogen fixation refers to the oxidatio

What is quaternary structure of a protein, Q. What is quaternary structure ...

Q. What is quaternary structure of a protein? Do all proteins have quaternary structure? The quaternary protein structure is the spatial conformation due to interactions among

What are the major natural plant hormones and their effect, What are the ma...

What are the major natural plant hormones and what are their respective effects? The major natural plant hormones and their respective functions are the following- Auxins that

Blastulation, BLASTUL A TIO N - Type of blastula is blastocyst or...

BLASTUL A TIO N - Type of blastula is blastocyst or trophoblastula. Outer layer of cell becomes flat and form trophoblast or trophoectoderm which receives nutritive ma

Dietary modification, Q. Dietary modification? Dietary modification inc...

Q. Dietary modification? Dietary modification includes nutritional support that allows normal growth and development. Plasma phenylalanine concentration between the range of 40

State the process of rna editing, Which of the following is a true statemen...

Which of the following is a true statement regarding the process of RNA editing? A. RNA editing changes the sequence of the mRNA message thereby permitting for enhance in prote

Define hexose monophosphate pathway, Define hexose monophosphate pathway ...

Define hexose monophosphate pathway The hexose monophosphate pathway (HMP also called the pentose phosphate pathway, or phoshogluconate pathway) consists of Mo irreversible o

What is barfoed test and explain its principle, What is Barfoed's test and ...

What is Barfoed's test and its principle? This test is a specific test for monosaccharides. Principle This test is also a copper reduction test but differs from Fehling

Surgical considerations in anterior mandibular region, Surgical Considerati...

Surgical Considerations in anterior mandibular region During the harvesting of a monocortical symphyseal block of bone from the mandibular symphysis region (autogenous block bo

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