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

Source of cells for regeneration, Source of Cells for Regeneration It...

Source of Cells for Regeneration It had been considered earlier that interstitial cells constitute a reserve of undifferentiated cells that provide the cellular material for

Are the phloem and the xylem made of living cells, Are the phloem and the x...

Are the phloem and the xylem made of living cells? The cells of phloem are living cells and the cells that constitute the xylem ducts are dead cells killed by the lignin deposi

What is the speech perception test, What is the Speech Perception Test ...

What is the Speech Perception Test The subject is asked to listen to a series of 60 sounds, each of which consists of a double e digraph with varying prefixes and suffixes. The

How genetic predisposition causing the underweight, How Genetic Predisposit...

How Genetic Predisposition causing the underweight? Mother's Health Status; Poor nutritional status of the girl child coupled with under nutrition during pregnancy results in L

Example of a fixed joint, Give one example in each case of (a) a fixe...

Give one example in each case of (a) a fixed joint, (b) a ball and socket joint, (c) a hinge joint.   (a) The bones of the skull, the junction of pelvic gi

What does radial symmetry mean, What does radial symmetry mean? What is the...

What does radial symmetry mean? What is the type of symmetry found in chordates? Which are other phyla of the animal kingdom that present species with radial symmetry? Radial

Family of proteins for cell adhesion, Why do we need a family of proteins f...

Why do we need a family of proteins for cell adhesion (what is the advantage of having a family of proteins?)

Define heterochromatin, Heterochromatin: Compact, gene-poor areas of a gen...

Heterochromatin: Compact, gene-poor areas of a genome, which are enriched in the simple sequence repeats. As it may be impossible to clone, heterochromatin is generally ignored wh

Enzymes, If a person lying quite still why does he or she need energy for?

If a person lying quite still why does he or she need energy for?

What respectively are zygotic meiosis, What respectively are zygotic meiosi...

What respectively are zygotic meiosis, gametic meiosis and sporic meiosis? Zygotic meiosis is the one that happens in the haplontic haplobiontic life cycle. Gametes from adult

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