Reconstruction of metabolic pathways, protein expression and homeostasis machineries across maize bundle sheath and mesophyll chloroplasts: large scale quantitative proteomics using the first maize genome assembly

摘要

This study provides a reconstruction of how metabolic pathways, protein expression and homeostasis functions, are quantitatively. distributed across BS and M chloroplasts. This yielded new insights in cellular specialization. A bioinformatics workflow was developed to deal with gene models, protein families and gene duplications related to the polyploidy of maize. 1105 proteins were assigned as potential chloroplast proteins, annotated for function, and quantified. Near complete coverage of primary carbon metabolism, starch and tetrapyrole metabolism, as well as excellent coverage for fatty acid synthesis, isoprenoid, sulfur, nitrogen and amino acid metabolism, was obtained. This showed e.g. quantitative and qualitative cell-type specific specialization in starch biosynthesis, Arg synthesis, N-assimilation, initial steps in S-assimilation. Protein annotation and identification data, and projection of matched peptides on the protein models, are available online through the Plant Proteome Database, PPDB.