lipochitooligosaccharide

Lipochitooligosaccharides, often abbreviated as LCOs, are a class of bioactive glycolipids found primarily in symbiotic bacteria, particularly rhizobia. They are characterized by a short chitin oligomer backbone, typically consisting of 3 to 5 N-acetylglucosamine units, to which fatty acid chains are attached. The specific structure of the fatty acid and the degree of acetylation on the glucosamine residues can vary, leading to a diverse range of LCO molecules.

LCOs play a crucial role in establishing symbiotic relationships between plants and nitrogen-fixing bacteria. In legumes, for instance, rhizobial LCOs act as signaling molecules that are recognized by specific plant receptors. This recognition initiates a cascade of events leading to the formation of root nodules, specialized structures where the bacteria reside and fix atmospheric nitrogen into a form usable by the plant. The diversity of LCO structures likely contributes to the specificity of these plant-microbe interactions, with different plant species or even cultivars responding to distinct LCO signals.

Beyond their role in symbiosis, LCOs have garnered interest for their potential applications in agriculture and medicine. Their ability to modulate plant growth and defense responses is being explored for use as biostimulants and biopesticides. In medicine, research is investigating their immunomodulatory properties and potential therapeutic effects. The complexity of LCO synthesis and the diversity of their structures present challenges for large-scale production and thorough characterization, but ongoing research continues to shed light on their biological functions and potential uses.