Fig 1.
Common lipid species reported for Chlamydomonas reinhardtii cells.
Labels R1, R2 and R3 represent different fatty acid acyl residues.
Fig 2.
Annotation of complex lipids in algae by matching nanoelectrospray-linear ion trap MS/MS low resolution fragment spectra against the UC Davis LipidBlast library.
Mass accuracy is <0.4 Da. Upper left panel: Annotation of the MS/MS spectrum from precursor m/z 750.9 Da as betaine lipid DGTS 35:2 (16:0/19:2); Upper right panel: Annotation of betaine lipid DGTS 36:2 (18:0/18:2); Lower left panel: Annotation of triacylglycerol TAG 56:0 (16:0/20:0/20:0); Lower right panel: Annotation of triacylglycerol TAG 61:0 (20:0/20:0/21:0).
Table 1.
Annotated lipids in C. reinhardtii under nitrogen and sulfur stress conditions.
The reverse dot product represents the level of confidence from in silico-MS/MS library search. Compound annotations without reverse dot product were annotated using MS2Analyzer.
Fig 3.
Growth curves of C. reinhardtii after transfer to nitrogen-deprived (left panel) or sulfur-deprived media (right panel).
The values are averages ±SE (standard deviation) for six replicate culture flasks.
Fig 4.
Partial Least Square supervised multivariate analysis of lipids under nutrient deprivation conditions at time points ranging from 1h, 4h, 10h, 18h and 26h.
Closed symbols reflect samples taken at early exponential growth rates, open symbols denote samples harvested at late growth stages. Left panel: Lipidomic phenotypes of C. reinhardtii cells grown under normal nitrogen-containing media (TAP, 100%N) or under reduced nitrogen conditions (N75%, blue, and N50%, red). Right panel: Lipidomic phenotypes of C. reinhardtii cells grown under normal sulfur-containing media (TAP, 100%S) or under reduced sulfur conditions (S75%, blue, and S50%, red).
Fig 5.
Univariate box-whisker plots of triacylglycerol and betaine lipid species in C. reinhardtii in temporal response to nitrogen deprivation.
Arithmetic mean values with ±S.E. as box and ±1.96 S.E. as whiskers.
Fig 6.
Univariate box-whisker plots of triacylglycerol, betaine and sulfoquinovosyl lipid species in C. reinhardtii in temporal response to sulfur deprivation.
Arithmetic mean values with ±S.E. as box and ±1.96 S.E. as whiskers.