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

Polysaccharides, PO L YSACCHARIDES Polysaccharides are complex car...

PO L YSACCHARIDES Polysaccharides are complex carbohydrates. Polysaccharides are also called glycans. These are insoluble in water. Polysaccharides are not swee

What is vena cava, What is vena cava? Which type of blood circulates within...

What is vena cava? Which type of blood circulates within the vena cava? The vena cava are either of two large veins that debouch into the right atrium. The superior vena cava d

Explain nevirapine and its adverse effects, Explain Nevirapine and its adve...

Explain Nevirapine and its adverse effects Nevirapine (NVP,Viramune) - Nevirapine is most effective at raising CD4 cell counts and lowering viral load when combined with 2 NRTI

Name an artificial fertiliser which farmers can use, Name an artificial fer...

Name an artificial fertiliser or fertilisers which farmers can use to increase the supply of nitrate, phosphate and potassium to their crops.   NPK compound fertiliser havin

Into which classes are mollusc divided, Into which classes are mollusc divi...

Into which classes are mollusc divided? What are some representing beings of each class? The phylum Mollusca is separated into five major classes: pelecypods, or bivalves (Pele

Foods incriminated, Foods that are frequently incriminated in staphylococca...

Foods that are frequently incriminated in staphylococcal food poisoning include meat and meat products, poultry and egg products, egg, tuna, chicken, potato and macaroni, bakery pr

Osmoregulation, explain osmoregulation in crustacean ?

explain osmoregulation in crustacean ?

Explain about the management of food allergies, Normal 0 false ...

Normal 0 false false false EN-IN X-NONE X-NONE

What is the equilibrium state of the system, For each of the cases that fol...

For each of the cases that follow, list as many properties of the equilibrium state as you can, specially the constrains placed on the equilibrium state of the system by its surrou

Explain the process of degradation of proteins, Q. Explain the process of D...

Q. Explain the process of Degradation of Proteins? Proteins are composed of amino acids combined by peptide linkages. The native proteins are resistant to attack by microo

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