Plants Immune Systems
Khalan A.
AP Biology
Plants Immune Systems
Plants serve as the main source of nutrients for countless organisms such as fungi, protists, vertebrates, and insects. In comparison to humans, a plant’s “immune system” is insignificant. However, plants have adapted and evolved chemical, physical, and protein based mechanisms to protect themselves against invaders.
A plant’s first line of defense against pathogens is their innate immunity. The “innate-immune system” is a non-specific immune system and responds to any recognizable pathogens in a general manner. An example of an innate immune defense would be a plant’s outer layer of waxy skin or cuticle that protects it from bacteria, the same way that a human’s epithelial surfaces protect it from invaders. A plant’s immune system is non-specific, but is not categorized with the non-specific immune system of invertebrates because a plant’s immune system is inheritable.
An example of a physical defense against herbivory that plants have would be thorns on a rose. The thorns repel any invaders from eating them because they prick and hurt. Note that plants cannot fully prevent herbivore predation because they are the bases of the food chain, but they have adapted these defenses to avoid excess predation.
Chemical defenses against herbivores are usually secreted toxins with an unpleasant taste or smell that repel any potential threats to the plant. Take the chemical canavanine for example, kills herbivores by poisoning them. The poison resembles an amino acid “arginine” and when an insect eats a plant with traces of canavanine, the canavanine impersonates the arginine and kills the insect. This is another rnon-specific immune response that kills general invaders on contact with poison.
The hypersensitive response to invasion in plants is a form of cell death that rapidly kills all the cells near the affected area. What this looks life to the human naked eye would be white or discolored blotches on a
AP Biology
Plants Immune Systems
Plants serve as the main source of nutrients for countless organisms such as fungi, protists, vertebrates, and insects. In comparison to humans, a plant’s “immune system” is insignificant. However, plants have adapted and evolved chemical, physical, and protein based mechanisms to protect themselves against invaders.
A plant’s first line of defense against pathogens is their innate immunity. The “innate-immune system” is a non-specific immune system and responds to any recognizable pathogens in a general manner. An example of an innate immune defense would be a plant’s outer layer of waxy skin or cuticle that protects it from bacteria, the same way that a human’s epithelial surfaces protect it from invaders. A plant’s immune system is non-specific, but is not categorized with the non-specific immune system of invertebrates because a plant’s immune system is inheritable.
An example of a physical defense against herbivory that plants have would be thorns on a rose. The thorns repel any invaders from eating them because they prick and hurt. Note that plants cannot fully prevent herbivore predation because they are the bases of the food chain, but they have adapted these defenses to avoid excess predation.
Chemical defenses against herbivores are usually secreted toxins with an unpleasant taste or smell that repel any potential threats to the plant. Take the chemical canavanine for example, kills herbivores by poisoning them. The poison resembles an amino acid “arginine” and when an insect eats a plant with traces of canavanine, the canavanine impersonates the arginine and kills the insect. This is another rnon-specific immune response that kills general invaders on contact with poison.
The hypersensitive response to invasion in plants is a form of cell death that rapidly kills all the cells near the affected area. What this looks life to the human naked eye would be white or discolored blotches on a