The Plant Immune System (ISP)
It is responsible for the plants having been able to survive for millennia and overcome different types of biotic stresses (pests and diseases)
It works in different ways depending on the type of biotic stress plants are facing.
Sucking insects and mites
Antixenosis
“Repellency”. The Immune System can release different volatile compounds (terpenes and other compounds) causing this repellency.
Antibiosis
“Antibiotic effect”. The Immune System can produce different compounds such as jasmonic acid and various specific phytoalexins that can affect insects / mites, reducing their ability to feed, reproduce, etc.
Tolerance
The Immune System can make plants tolerate stress not affecting their growth or general development.
Necrotrophic fungi
Callose
The Immune System works by thickening and strengthening the cell wall through the accumulation of callose * (physical barrier) that hinders the penetration and expansion of fungal hyphae.
* Callose is a polysaccharide produced by plants in response to stress or damage stimuli.