Stimulation of plant innate immunity by natural and synthetic elicitors is a promising alternative to conventional pesticides for a more sustainable agriculture. Sugar-based bolaamphiphiles are known for their biocompatibility, biodegradability and low toxicity. In this work, we show that Synthetic Rhamnolipid Bolaforms (SRBs) that have been synthesized by green chemistry trigger Arabidopsis innate immunity. Using structure-function analysis, we demonstrate that SRBs, depending on the acyl chain length, differentially activate early and late immunity-related plant defense responses and provide local increase in resistance to plant pathogenic bacteria. Our biophysical data suggest that SRBs can interact with plant biomimetic plasma membrane and open the possibility of a lipid driven process for plant-triggered immunity by SRBs.

Plant oxylipins produced following oxidation of unsaturated fatty acids are structurally diverse metabolites that play crucial developmental and defensive roles. Whereas free oxylipins are well studied, oxylipins esterified in complex lipids such as galacto-and phospholipids are thought to be rare and have unclear roles. In the last few years, new analytical methods have been developed, leading to the discovery of many esterified oxylipins in a variety of plant species. This suggests that these molecules may be ubiquitous plant metabolites. While their precise functions are unclear, esterified oxylipins seem to play important roles in plant development and defense. This review focuses on new insights regarding diversity, biosynthesis and function of those interesting and understudied molecules. Keywords Arabidopsides Á Jasmonates Á Lipoxygenase Á Oxylipins Á Plant defense Abbreviations (dn)OPDA OPDA and dnOPDA A. thaliana Arabidopsis thaliana (L.) Heynh ACX1 Acyl-coenzyme A oxidase 1 ADH Alcohol dehydrogenase AGAP1 Acylated galactolipid associated phospholipase 1 AOC Allene oxide cyclase AOS Allene oxide synthase DES Divinyl ether synthase 4,5-ddhJA 4,5-Didehydro-jasmonic acid DGDG Digalactosyldiacylglycerol DGMG Digalactosylmonoacylglycerol dnOPDA 12-Dinor-oxo-phytodienoic acid DOX a-Dioxygenase DW Dry weight EAS Epoxy alcohol synthase EPB Epibrassinolide FW Fresh weight GC Gas chromatography

No abstract