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

Maturation phase, Maturation Phase The Maturation phase characterizes...

Maturation Phase The Maturation phase characterizes he transformation of diploid primary spermatocytes into haploid spermatids. The primary spermatocyte divides meiotically t

To show the direction of sprout growth in seeds, To show the direction of s...

To show the direction of sprout growth in seeds Soak pumpkin or other large seeds overnight and fasten three of them on needles as shown in the diagram. Fasten single with the

How water balance take place in human body, How Water Balance Take Place in...

How Water Balance Take Place in Human Body? The amount of fluid in the body is tightly controlled because imbalance can be devastating. In a normal individual, the maintenance

Explain phylum phytofagellata, Phylum Phytofagellata (Plant flagellates...

Phylum Phytofagellata (Plant flagellates) 1) At some stage of life cycle they have one or more flagella. The flagella are used for locomotion. 2) Photosynthetic protistan

Division of the exconjugant into daughter paramoecia, Division of the excon...

Division of the exconjugant into daughter paramoecia: Each exconjugant, with a single micronucleus and four macronuclei divides twice and forms four daughter paramoecia. E

What is the difference among plasma membrane and cell wall, Plasma membrane...

Plasma membrane and cell wall is not the similar thing. Plasma membrane, also known as cell membrane, is the outer membrane common to all living cells and it is made of a phospholi

Can you define p-waves, Q. Can you define P-Waves? Changes in P-wave mo...

Q. Can you define P-Waves? Changes in P-wave morphology have been well described in resting tracings and are very useful in identifying right and left sided hemodynamic alterat

Explain the expansion of the universe, Using the Raisin Bread model from th...

Using the Raisin Bread model from the textbook, describe the expansion of the universe. Do the galaxies expand also?

Placenta, PLACENTA - A common tissue of foetus & mother (uterus) which ...

PLACENTA - A common tissue of foetus & mother (uterus) which is physical, physiological & endocrinal connection is known as placenta. FUNCTIO N - To provide nutrients

What do you mean by hypertension, Q. What do you mean by Hypertension? ...

Q. What do you mean by Hypertension? Hypertension is one of the major risk factors for cardiovascular disease. It is the most common public health problem and often referred to

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