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

Environment and health- impact of air and water pollution, Environment and ...

Environment and Health- Impact of Air and Water Pollution Environment includes a host of factors of which air and water are the two major components. Air pollution is caused b

Describes the role that restriction enzymes play in bacteria, Which of the ...

Which of the following best describes the role that restriction enzymes play in bacteria? A. Restriction enzymes recognize and digest bacteriophage genomes after an initial inf

Describe how a phagocyte destroys bacteria, Describe how a phagocyte destro...

Describe how a phagocyte destroys bacteria. The phagocyte forms a pouch in its cell membrane and engulfs bacteria in the pouch. It then pinches off the pouch to produce a vesi

Define drug-nutrient interaction and drug- drug interactions, Define drug-n...

Define drug-nutrient interaction and drug- drug interactions? Generally, administering oral medication along with the food or at a mealtime is a convenient manner of drug dosin

Solubility, Solubility You are aware that gases are soluble in liquid...

Solubility You are aware that gases are soluble in liquid. Solubility of a gas in a liquid depends on the partial pressure, temperature and presence of other solutes. Table

Define plan showing various steps of non-enzymatic browning, Define Plan sh...

Define Plan showing various steps of non-enzymatic browning? The plan showing the various steps of non-enzymatic browning is presented in figure Figure:

Define role in protein metabolism and growth, Define Role in protein metabo...

Define Role in protein metabolism and growth? Severe vitamin A deficiency results in abnormal RNA metabolism and protein synthesis and hence interferes with growth. Hence vitam

Quantification of pulmonary stenosis, Quantification of Pulmonary Stenosis ...

Quantification of Pulmonary Stenosis :   Quantification by ECHO By Valve area Mild                 > 1.5 cm 2 Moderate         0.5-1.5 cm 2 Severe

Illustrate the techniques of neurology, Illustrate the techniques of neurol...

Illustrate the techniques of neurology A long-standing technique in neurology has been observed the effects on behaviour of lesions (cutting) or ablation (removal) of nerve tis

Determine the symptoms of bacillus cereus, Determine the Symptoms of bacill...

Determine the Symptoms of bacillus cereus Extremely large numbers (10 8 per gram) of viable cells of B. cereus must be ingested to develop signs and symptoms of the syndrome.

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