What is it?
Oligochitosan is the deacetylated derivative of chitin obtained from shrimp or crab shell chitin by alkaline deacetylation. Oligochitosan is biodegradable, non-toxic and biocompatible and has proven useful in plant production due to its dual function in terms of both its direct antifungal effects and the elicitation of defence mechanisms in plants.
How does it work?As they grow, plant pathogens release certain proteins (by-products/cell wall fragments etc.) into the environment. Plant cells have developed the ability to detect some of these compounds which then become elicitors of the plant's resistance responses. If elicitors can be identified and commercially produced, they can be used to trigger/boost a plant's natural defence mechanisms.
Oligochitosan is one such elicitor, capable of stimulating natural defence response systems in treated plants. Poly-D-glucosamine (the building blocks of oligochitosan) binds to fungal receptor sites, mimicking an attack by fungal spores. As a result a signalis sent to the cell nucleus, triggering defence responses.
Summary of reported results obtained from
use of Chitin I Chitosan I Oligochitosan
Such responses include:1. The deposition of physical barriers (silicon, callose, cellulose etc).
2. The production of anti-microbial compounds called phytoalexins (e.g.chitinase enzymes).