Specialized Metabolism in a Nonmodel Nightshade: Trichome Acylinositol Biosynthesis

• Published in: Plant physiology (Bethesda) Vol. 183; no. 3; pp. 915 - 924
• Main Authors: Leong, Bryan J, Hurney, Steven M, Fiesel, Paul D, Moghe, Gaurav D, Jones, A Daniel, Last, Robert L
• Format: Journal Article
• Language: English
• Published: United States 01-07-2020
• Subjects: Acylation; Biosynthetic Pathways; Genetic Variation; Inositol - biosynthesis; Solanum - genetics; Solanum - metabolism; Solanum lycopersicum - genetics; Solanum lycopersicum - metabolism; Trichomes - metabolism
• ISSN: 0032-0889; 1532-2548
• DOI: 10.1104/pp.20.00276

Plants make many biologically active, specialized metabolites, which vary in structure, biosynthesis, and the processes they influence. An increasing number of these compounds are documented to protect plants from insects, pathogens, or herbivores or to mediate interactions with beneficial organisms, including pollinators and nitrogen-fixing microbes. Acylsugars, one class of protective compounds, are made in glandular trichomes of plants across the Solanaceae family. While most described acylsugars are acylsucroses, published examples also include acylsugars with hexose cores. The South American fruit crop naranjilla (lulo;
) produces acylsugars containing a myoinositol core. We identified an enzyme that acetylates triacylinositols, a function homologous to the last step in the acylsucrose biosynthetic pathway of tomato (
). Our analysis reveals parallels between
acylsucrose and
acylinositol biosynthesis, suggesting a common evolutionary origin.