What is Plant Defense?

When a plant is attacked by fungus, it pinches the cell wall, further disrupting it and in response to that, plant liberate hydrogen peroxide. This is the defense mechanism of plant. There are various ways, the first one is where hydrogen peroxide will stop the cell wall from getting disrupted.

To dissociate the plants, pathogens will require enzymes like pectinase and other enzymes to disintegrate the cell wall. Thus, the enzyme liberated by the fungal pathogen has to be halted or its action has to be terminated, which is done by the hydrogen peroxide.

Its mechanism can be explained from the following steps. Once the hydrogen peroxide is liberated, it further will reach the area where it would be working on, the cell wall.

Hydrogen peroxide will interact peroxidase enzyme which will disintegrate pectinase. Thus, pectinase will not be able to damage the cell wall and the problem is solved. Another mechanism of hydrogen peroxide is liberating the phytoalexins, which are the antiviral proteins. These phytoalexins stop synthesis of protein within cells, when the plants is invaded by a pathogen, in this case fungus.

The fungus, also liberates certain chemicals, which makes the fungus known that there is a pathogen in the vicinity. In the plasma membrane, hydrogen peroxide, transfers the message through a response, that there is a cell which is invaded.

After mrna is formed it moves to cytoplasm from nucleus, where ribosomes will carry out synthesis of protein and phytoalexins will be generated, which will act like antiviral proteins.

If in the cell, phytoalexins is available, synthesis of protein will be stopped and eventually, even the pathogen’s growth will be ceased, thus the pathogen will be banished.