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

Counselling for day to day management, Q. Counselling for day to day Manage...

Q. Counselling for day to day Management? As we know that diabetes is a chronic disease, a major part of its control requires counselling the patient and his family for day to

Explain imiquimod, Imiquimod (Aldara) This immunomodulator is FDA-appro...

Imiquimod (Aldara) This immunomodulator is FDA-approved for topical treatment of external and perianal genital warts, which are caused by papillomavirus. Gradual clearance of w

Explain nutritional requirements of microbes, Explain Nutritional Requireme...

Explain Nutritional Requirements of Microbes? Microorganisms require various nutrients and physical factors for their existence and growth. Nutrients are substances used in bio

What is the structural representation of a carboxyl group, What is the stru...

What is the structural representation of a carboxyl group? Carboxyl groups have a carbon attached to single hydroxyl group by a simple bond and to one oxygen by a double bond.

Effects of malnutrition, Effects of malnutrition The effects of maln...

Effects of malnutrition The effects of malnutrition are not the same in adults and children. When the amount of food is not sufficient or when the nutrients are missing f

Hydrophilicity plot, Hydrophilicity Plot is a computer plot which checks t...

Hydrophilicity Plot is a computer plot which checks the relative summed hyrophobicity or hydrophilicity of adjacent amino acid sidechains (usually within a moving window of about

Lipoproteins help in transport of lipids, Four major groups of lipoproteins...

Four major groups of lipoproteins help in transport of lipids. These include: 1.  Chylonzicrons-function is to carry dietary triacylglycerols 2.  Very  low  density lipoprot

Insulin, INSULIN Linear polymer of b-D-Glucose. Insulin is small-...

INSULIN Linear polymer of b-D-Glucose. Insulin is small-sized (25 - 35 residues) fructosan homopolysaccharide which is a reserve carbohydrate present in roots, tubers and

Explain erythema migrans, Erythema migrans Oral antibiotic therapy sho...

Erythema migrans Oral antibiotic therapy shortens the duration of the rash and generally prevents development of late sequelae. Among the 3 drugs used for this indication, onl

Medtronic hancock-biological valves, Medtronic Hancock (Standard Model) :  ...

Medtronic Hancock (Standard Model) :  These are gluteraldehyde preserved xenograft aortic valve, which are mounted. The modified orifice version (M-0) is one where the right

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