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

Xenotransplantation, X e n o t r a n s p l a n t a t i o ...

X e n o t r a n s p l a n t a t i o n Over the past 20 years transplantation of heart and kidney has become almost a routine in human but the availability of

What is the structure that maintains identical chromatids, What is the stru...

What is the structure that maintains identical chromatids bound? The structure that maintains identical chromatids bound is the centromere. Cell Nucleus Review - Image Diver

Explain hazard identification, Explain Hazard identification Hazard id...

Explain Hazard identification Hazard identification   is "the  identification of biological, chemical and physical agents capable of causing adverse health effects and which m

Define the different forms of protein energy malnutrition, Define the Diffe...

Define the Different Forms of Protein Energy Malnutrition? The term PEM is used to describe a wide range of clinical conditions ranging 'from the very clinically detectable flo

Cells, What surrounds a plant cell

What surrounds a plant cell

Laboratory tests - evaluation of heart failure, Routine blood tests like ha...

Routine blood tests like haemoglobin, creatinine, electrolytes are useful to plan treatment. More recently the blood natriuretic peptide levels have been used to assess heart failu

Define morphallaxis, a) Describe with the help of a suitable example for ea...

a) Describe with the help of a suitable example for each of the following terms : (i) morphallaxis (ii) epimorphosis and (iii) compensatory regeneration.

Define the basic concepts behind the spectral techniques, Define the Basic ...

Define the Basic Concepts behind the Spectral Techniques? Energy is transmitted via electromagnetic waves that are characterized by their frequency and wavelength. The physical

Brain region that triggers the voluntary motor activity, Which is the brain...

Which is the brain region that receives conscious sensory information? Which is the brain region that triggers the voluntary motor activity? In the brain conscious sensory info

Explain the drug effects on absorption of nutrients, Explain the Drug Effec...

Explain the Drug Effects on Absorption of Nutrients? Many drugs can impair, prevent or reduce absorption of nutrients due to: Formation of insoluble complexes: many drugs

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