Acylsugars are a group of plant-derived protective secondary metabolites that lack nitrogen. They typically consist of aliphatic acyl groups of low to medium chain lengths esterified to the hydroxyl groups of glucose or sucrose. Presence of such acyl groups gives these compounds hydrophobic properties. This group of compounds has been extensively studied in tomato and related species, in which these compounds are produced and secreted in sporadic amounts from trichomes on the plant leaf and stem surface. Production of copious quantities of these acylsugars give a sticky feel to the plant tissue. In particular, this flower has shown to distract herbivorous insect pests against thrips damage. It is believed that acylsugars provide physical and/or chemical defense to the plant.
Acylsugars are nonvolatile and viscous polyesters that consist of acyl chains on sucrose or glucose backbones. These attached acid chains may vary in length from short to medium which affects the phenotypic characteristics of the plant. Other factors that may affect plant phenotype includes the presence of either glucose or sucrose, the number of acyl chains as well as the total amounts of acyl sugars.
Acylsugars are produced in the secretory glandular trichomes of various plants, specifically those that belong to the family Solanaceae. These compounds are identified to be responsible for physical and/or chemical defense plant defense. Additionally, potential commercial applications were also found in these compounds.
The function of acylsugars has been the subject of much research. For instance, acylsugars in Solanum pennellii discourage pests from laying eggs and contain compounds that are toxic to herbivores. A study showed that this natural insect-repellent property may lead to the breeding and development of a thrips-resistant tomato which could be of commercial benefit. Additionally, acylsugars from other genera were also found to give protection against herbivores and plant pathogens.
Acylsugars are also used in pesticides, food additives, cosmetics and personal care products, antibiotics, and anti inflammatory medications. Therefore acylsugars have been the focus of studies aiming to discover successful breeding crop techniques and synthetic methods of metabolizing acylsugars.
- Gonzales-Vigil, E.; Kim, K. K.; Shi, F.; Jones, D.; Barry, C.; Last, R. (December 2012). "Striking natural diversity in glandular trichome acylsugar composition is shaped by variation at acyltransferase2 locus in the wild tomato Solanum habrochaites". Plant Physiology. 160 (2012): 1854–1870. doi:10.1104/pp.112.204735. PMC 3510116. PMID 23054567.
- D'Ambrosio, D. A.; Mutschler, M.; Walgenbach, J.; Kennedy, G. (November 2013). "The effect of acylsugars of the wild tomato Solanum pennellii on the oviposition behaviour of western flower thrips (Frankliniella occidentalis) and tobacco thrips (Frankliniella fusca)". ResearchGate.
- Kim, K. K.; Ji, W. M.; McKnight, T. (April 2018). "Candidate gene network for acylsugar metabolism and plant defense in wild tomato Solanum pennellii". Plant Physiology. 160 (2012): 1854–1870. doi:10.1104/pp.112.204735. PMC 3510116. PMID 23054567.