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

How is the circulatory system of reptiles characterized, Q. How is the circ...

Q. How is the circulatory system of reptiles characterized? What is the basic difference between the amphibian and the reptile heart? The circulatory system of beings of the cl

Asexual reproduction and cloning in plants, before stem cuttings are plante...

before stem cuttings are planted the cut end of the stem is often dipped in a hormone powder .what is the point of this?

What are genotypes and respective blood types of abo system, What are the g...

What are the genotypes and respective blood types of the ABO system? Ever since the alleles are IA, IB and i the possible genotypes are IAIA (blood type A), IAIB (blood type AB

Explain microbiology of vegetables, Q. Explain Microbiology of vegetables? ...

Q. Explain Microbiology of vegetables? Ans. All of us are well aware that vegetables are grown in soil, which, we already know, are a rnajor support system for the mi

Zoonoses disease-contagious ecthyma/orf , Contagious ecthyma/ Orf Primaril...

Contagious ecthyma/ Orf Primarily it is a disease of sheep and goats caused by a dermotropic virus - Orf virus - that belongs to the Parapoxvirus genus of the family Poxviridae. T

Ecological adaptations in animals to desert environment, Ecological adaptat...

Ecological adaptations in animals to desert environment In response to scarcity of water, animats adcipt vario6s strategies to conserve or prevent loss of water. Most of the de

Molluscan kidney, Normal 0 false false false EN-IN X-...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Difference between dominant epistasis and recessive epistasi, What is epist...

What is epistasis? What is the difference between dominant epistasis and recessive epistasis? The Epistasis is the gene interaction in which a gene (the epistatic gene) able to

Define factors affecting energy expenditure and requirement, Define Factors...

Define Factors Affecting Energy Expenditure and Requirement? As mentioned earlier, the energy needs vary widely among individuals in a group. Why? A number of factors cause the

Genetics, What are the Elements of Heredity and variations?

What are the Elements of Heredity and variations?

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