A novel regulatory system in plants involving medium-chain fatty acids.
Polyethylene glycol sorbitan monoacylates (Tween) are detergents of widespread use in plant sciences. However, little is known about the plant response to these compounds. Interestingly, the structure of Tweens' detergents (especially from Tween 20) resembles the lipid A structure from gram-negative bacteria polysaccharides (a backbone with short saturated fatty acids). Thus, different assays (microarray, GC-MS, RT-PCR, Northern blots, alkalinization and mutant analyses) were conducted in order to elucidate physiological changes in the plant response to Tween 20 detergent. Tween 20 causes a rapid and complex change in transcript abundance which bears all characteristics of a pathogenesis-associated molecular pattern (PAMP)/elicitor-induced defense response, and they do so at concentrations which cause no detectable deleterious effects on plant cellular integrity. In the present work, it is shown that the PAMP/elicitor-induced defense responses are caused by medium-chain fatty acids which are efficiently released from the Tween backbone by the plant, notably lauric acid (12:0) and methyl lauric acid. These compounds induce the production of ethylene, medium alkalinization and gene activation in a jasmonate-independent manner. Medium-chain fatty acids are thus novel elicitors/regulators of plant pathogen defense as they have being proved in animals.
Hunzicker
Gretel Mara
GM
Instituto Multidisciplinario de Biología Vegetal, CONICET-Universidad Nacional de Córdoba, Av. Vélez Sarsfield 299, Casilla de Correo 495, Córdoba, 5000, Argentina. ghunzicker@imbiv.unc.edu.ar
D000473:Alkanes / Q000494:pharmacology; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics; D003517:Cyclopentanes / Q000494:pharmacology; D003902:Detergents / Q000494:pharmacology; D005030:Ethylenes / Q000096:biosynthesis; D005110:Extracellular Space / Q000187:drug effects / Q000378:metabolism; D005227:Fatty Acids / Q000494:pharmacology*; D008401:Gas Chromatography-Mass Spectrometry; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects*; D017343:Genes, Plant / Q000235:genetics; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D018551:Solanum lycopersicum / Q000187:drug effects / Q000235:genetics; D009154:Mutation / Q000235:genetics; D054883:Oxylipins / Q000494:pharmacology; D018515:Plant Leaves / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D010944:Plants / Q000187:drug effects* / Q000235:genetics*; D011136:Polysorbates / Q000737:chemistry / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014026:Nicotiana / Q000187:drug effects / Q000235:genetics; D015854:Up-Regulation / Q000187:drug effects
D000473:Alkanes; D003517:Cyclopentanes; D003902:Detergents; D005030:Ethylenes; D005227:Fatty Acids; D054883:Oxylipins; D010940:Plant Proteins; D011136:Polysorbates; D012333:RNA, Messenger; C011006:jasmonic acid; C036216:ethylene