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

What is parasitism, What is parasitism? Parasitism is the ecological in...

What is parasitism? Parasitism is the ecological interaction in which a being lives at the expense of another. The parasite often does not cause immediate death of the host sin

Formation of vegetative and generative cells, Formation of Vegetative and G...

Formation of Vegetative and Generative Cells The division of a pollen grain results in two unequal cells-the vegetative cell and the generative cell. The pollen grain is herea

How to investigate mitral regurgitation by echo, Q. How to investigate mitr...

Q. How to investigate mitral regurgitation by Echo? 2 D echocardiography will help determine the morphology and etiology of mitral regurgitation. Rheumatic mitral regurgitation

Explain acyclovir, Explain Acyclovir Available in topical, oral, and in...

Explain Acyclovir Available in topical, oral, and intravenous (IV) formulations, acyclovir is used to treat herpes simplex virus (HSV) and varicella-zoster virus (VZV) infectio

Explain the toxicity of vitamin d, Explain the Toxicity of Vitamin D? ...

Explain the Toxicity of Vitamin D? The adverse effects of high vitamin D intakes include hypercalciuria (excessive urinary calcium excretion) and hypercalcaemia (high concentr

What is homogenization, What is homogenization Emulsions may also be st...

What is homogenization Emulsions may also be stabilized by a process known as homogenization, in which the size of the dispersed fat globules is greatly reduced to more or less

Skeleton, what is the biological significance of skeleton

what is the biological significance of skeleton

Define partition chromatography - basic separation technique, Define Partit...

Define Partition chromatography - basic separation technique? It is a technique in which separation is achieved as a consequence of the relative solubility of a substance in th

Explain pea plants in genetics, Explain pea plants in genetics? Pea Pl...

Explain pea plants in genetics? Pea Plants :   In pea plants, sperm are located in the pollen grains produced by the anthers of the flower. Eggs are formed in ovules, structur

Functions of albumin and myosin, Q. What are respectively some remarkable f...

Q. What are respectively some remarkable functions of albumin, myosin, CD 4 , keratin, immunoglobulin, reverse transcriptase, hemoglobin and insulin? Myosin is a protein that w

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