Updated project metadata. Methods were investigated that would deliver rapid and semi-quantitative analysis of the subcellular composition of Arabidopsis samples, as the standard technique for this i.e. immunoblotting is difficult to quantify and relies on a very few protein targets, whose responses to developmental or environmental cues are often not known. Spectral counts from shotgun analysis of different Arabidopsis tissues, cells or growth stages were compared to selected reaction monitoring (SRM) analyses of the same samples. Results were further compared to a novel protein abundance scoring method, MASCP Gator scoring, described in this study for the first time. The latter is reliant on previously collated public proteomics data and so provides an estimate of protein abundance even in the absence of de-novo experimentation. This scoring method is presented as an online tool, Multiple Marker Abundance Profiling (MMAP), available at http:SUBA.live. This submission comprises the shotgun data from this study. SRM results are available in a separate submission: http://www.peptideatlas.org/PASS/PASS00906