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 the role of lipoprotein, Explain the Role of Lipoprotein ? As d...

Explain the Role of Lipoprotein ? As discussed in the previous section, serum concentrations of Lp(a) are elevated in South Asians irrespective of their migrant status. Several

Explain adverse effects of acyclovir, Adverse Effects of Acyclovir By ...

Adverse Effects of Acyclovir By any route of administration, acyclovir is generally well tolerated. Gastrointestinal (GI) disturbances and headache can occur. Given IV, the dr

Desscribe formation of sperm cells from germ cells, Q. Indicating the name ...

Q. Indicating the name and respective ploidy of each involved cell how can the formation of sperm cells from germ cells be described? The formation of spermatogenesis or sperm

What are the dietitians services, What are the dietitians services Diet...

What are the dietitians services Dietitians are engaged in a variety  of  positions and  in a number of  work settings. Of course the largest proportion is  involved engaged in

Explain dietetics, Explain Dietetics Dietetics  has been defined as  t...

Explain Dietetics Dietetics  has been defined as  the science and art of feeding individuals based  on the principles of  nutrition. It can also be  said  to  be  the "science

Define foaming properties of proteins, Define Foaming Properties, Binding o...

Define Foaming Properties, Binding of Flavour and Other Substances? To understand the foaming properties of proteins, we need to know some basic aspects of foam foods. Foam foo

Female reproductive system - external genitalia, EXTERNAL GENITALIA - ...

EXTERNAL GENITALIA - Vestibule is covered by 2 pairs of lips labia majoris and labia minoris. At the anterior junction of labia minoris a small erectile clitoris presen

How the dna nanoarchitecturing works, Q. How the DNA nanoarchitecturing wor...

Q. How the DNA nanoarchitecturing works? DNA Nano architectures constructs that can be self-assembled from branched DNA molecules. Their components can be simple branched speci

Explain the purpose of preparation of isolates from protein, Purpose of the...

Purpose of the preparation of isolates from a protein The major purpose of the preparation of concentrates and isolates from a protein source is to increase the concentration 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