Hypersensitive Reaction

 What does it mean to have a hypersensitive response? Use an appropriate diagram to explain it.

Hypersensitive Reaction:

The hypersensitive reaction is a widely utilised strategy by hosts to limit pathogen transmission. Infected cells and those around them commit suicide by lignifying and producing antimicrobial chemicals, stopping the infection from spreading further and, in certain circumstances, killing it.

The hypersensitive reaction is explained as follows:

Although the hypersensitive response is thought to be a biochemical defence mechanism, it can also trigger cellular reactions. The cellular reactions, however, are not visible to the human eye or under a microscope. When a host-pathogen makes contact with a cell, the nucleus travels towards the invaders and disintegrates quickly. At the same moment, the cytoplasm changed into granules that looked like brown resin. As the browning of the cytoplasm of the plant cell proceeds. The hypersensitive reaction is triggered. When pathogens come into contact with cell membranes during infection, a hyper response is soon developed.

Hyper reaction occurs when the afflicted and surrounding cells quickly mobilise a cascade of defence responses, followed by the production of poisonous chemicals that destroy both the invading and surrounding cells, as well as the pathogen. The hypersensitive response is the climax of the plant6 defence responses, which are triggered by the plant's detection of pathogen-produced signal molecules called elicitors. The host plants recognise the elicitors, which triggers a chain of metabolic reactions in the attack and surrounding plant cells, resulting in new or changed cell activities. As a result, a number of highly active defense-related chemicals develop. A fast burst of reactive oxygen species (ROS) resulting to a dramatic increase in oxidation reaction is one of the most prevalent novel cell activities and chemicals. Other alterations include enhanced ion transport through the cell membrane, particularly K+ and H+.

However, the modifications cause disruption of the cell membrane and cellular organelles, as well as the formation of salicylic acid-induced antimicrobial compounds proteins, such as PR proteins. These PR proteins eventually lead to systemic acquired resistance and stop new infections from starting.