Elevated atmospheric CO 2 concentration and diurnal cycle induce changes in lipid composition in Arabidopsis thaliana

Summary•  Few studies regarding the effects of elevated atmospheric CO 2 concentrations on plant lipid metabolism have been carried out. Here, the effects of elevated CO 2 concentration on lipid composition in mature seeds and in leaves during the diurnal cycle of Arabidopsis thaliana were investigated. •  Plants were grown in controlled climate chambers at elevated (800 ppm) and ambient CO 2 concentrations. Lipids were extracted and characterized using thin layer chromatography (TLC) and gas liquid chromatography. •  The fatty acid profile of total leaf lipids showed large diurnal variations. However, the elevated CO 2 concentration did not induce any significant differences in the diurnal pattern compared with the ambient concentration. The major chloroplast lipids monogalactosyldiacylglycerol (MGDG) and phosphatidylglycerol (PG) were decreased at elevated CO 2 in favour of phosphatidylcholine (PC) and phosphatidylethanolamine (PE). Elevated CO 2 produced a 25% lower ratio of 16:1 trans to 16:0 in PG compared with the ambient concentration. With good nutrient supply, growth at elevated CO 2 did not significantly affect single seed weight, total seed mass, oil yield per seed, or the fatty acid profile of the seeds. •  This study has shown that elevated CO 2 induced changes in leaf lipid composition in A. thaliana , whereas seed lipids were unaffected.