Fig. 4: Coarse-grained proteomes can be used to assess nutrient stress.
From: Proteomic traits vary across taxa in a coastal Antarctic phytoplankton bloom
a, b Comparison of the single-protein biomarker plastocyanin with the photosynthetic protein mass fraction for diatoms and haptophytes (using discovery proteomics). Points are colored with their corresponding, sample-specific cofragmentation score (the number of potentially cofragmenting peptides). Cofragmentation scores were calculated using the sample-specific nucleic acid sequencing, and points colored in gray correspond to peptides that were identified and quantified with the “Metatranscriptome experiment (all)” database, but were not present in the sample-specific databases. c Comparison of the single-protein biomarker (using targeted proteomics) plastocyanin with the photosynthetic protein mass fraction for haptophytes. Two peptides for plastocyanin are shown, and each point represents one technical replicate measurement. Phaeocystis plastocyanin abundance is normalized to Phaeocystis RuBisCO small subunit abundance, where we used the mean of two taxon-specific peptides (AKPNFYVK and QIQYALNK) to calculate RuBisCO abundance [27].
