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

Endoplasmic reticulum (er), Endoplasmic reticulum (ER) is the network of m...

Endoplasmic reticulum (ER) is the network of membranous tubules in the cytoplasm of a cell; involved in production of the phospholipids, proteins, and the other functions. Rough E

What are the advanced surgical procedures, What are the Advanced surgical p...

What are the Advanced surgical procedures The scope of implantology has widened to include many more clinical situations which would be hitherto contraindicated for implants du

Deficiency diseases-parturient paresis , Parturient paresis (milk  fever, h...

Parturient paresis (milk  fever, hypocalcaemia) Parturient paresis is an acute to peracute non-febrile disease, which occurs in diary cows and buffaloes usually around the t

Equipment and supplies -pre-requisite of nursing unit, Equipment and Suppli...

Equipment and Supplies: Nurses who are aware of location of equipment and supplies do give accurate delivery of patient care without delay and wastage of  time and energy for

Cadmium, C adm iu m Like lead and mercury, cadmium is also non-essen...

C adm iu m Like lead and mercury, cadmium is also non-essential biologically. The industrial use of cadmium in plastic production, electroplating and manufacture of alloys a

Properties of transparency factors in corneal hydration, What are special p...

What are special properties of transparency factors in corneal hydration of cornea? The factors affecting the transparency include special properties of the corneal epitheliu

Define the left cerebral cortex, Which of the following is true for a prima...

Which of the following is true for a primary motor cortex (M1) corticospinal interneuron that produces action potentials during movements of the big toe of the right foot? A. A

Natality rate - natality, Natality Rate - Natality Natality rate or bi...

Natality Rate - Natality Natality rate or birth rate is determined by dividing the number of individuals born by unit time and is expressed as follows: Natality rate =  ΔNn

Skin, Two adaptation of the skin against attack by micro-organisms

Two adaptation of the skin against attack by micro-organisms

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