title: Proteomic analysis of chromoplasts from six crop species reveals insights into chromoplast function and development.
abstract: Chromoplasts are unique plastids that accumulate massive amounts of carotenoids. To gain a general and comparative characterization of chromoplast proteins, this study performed proteomic analysis of chromoplasts from six carotenoid-rich crops: watermelon, tomato, carrot, orange cauliflower, red papaya, and red bell pepper. Stromal and membrane proteins of chromoplasts were separated by 1D gel electrophoresis and analysed using nLC-MS/MS. A total of 953-2262 proteins from chromoplasts of different crop species were identified. Approximately 60% of the identified proteins were predicted to be plastid localized. Functional classification using MapMan bins revealed large numbers of proteins involved in protein metabolism, transport, amino acid metabolism, lipid metabolism, and redox in chromoplasts from all six species. Seventeen core carotenoid metabolic enzymes were identified. Phytoene synthase, phytoene desaturase, ζ-carotene desaturase, 9-cis-epoxycarotenoid dioxygenase, and carotenoid cleavage dioxygenase 1 were found in almost all crops, suggesting relative abundance of them among the carotenoid pathway enzymes. Chromoplasts from different crops contained abundant amounts of ATP synthase and adenine nucleotide translocator, which indicates an important role of ATP production and transport in chromoplast development. Distinctive abundant proteins were observed in chromoplast from different crops, including capsanthin/capsorubin synthase and fibrillins in pepper, superoxide dismutase in watermelon, carrot, and cauliflower, and glutathione-S-transferease in papaya. The comparative analysis of chromoplast proteins among six crop species offers new insights into the general metabolism and function of chromoplasts as well as the uniqueness of chromoplasts in specific crop species. This work provides reference datasets for future experimental study of chromoplast biogenesis, development, and regulation in plants.
authors: Department of Plant Breeding and Genetics, Cornell University,  Ithaca, NY 14853, USA.
authors: Yong-Qiang
authors: YQ
authors: Wang
authors: Yong
authors: Y
authors: Yang
authors: Zhangjun
authors: Z
authors: Fei
authors: Hui
authors: H
authors: Yuan
authors: Tara
authors: T
authors: Fish
authors: Theodore W
authors: TW
authors: Thannhauser
authors: Michael
authors: M
authors: Mazourek
authors: Leon V
authors: LV
authors: Kochian
authors: Xiaowu
authors: X
authors: Wang
authors: Li
authors: L
authors: Li
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D002212:Capsicum / Q000201:enzymology / Q000378:metabolism; D029441:Carica / Q000201:enzymology / Q000378:metabolism; D002338:Carotenoids / Q000096:biosynthesis; D060365:Chloroplast Proteins / Q000032:analysis / Q000378:metabolism; D025222:Chloroplast Proton-Translocating ATPases / Q000378:metabolism; D029773:Citrullus / Q000201:enzymology / Q000378:metabolism; D018556:Crops, Agricultural / Q000201:enzymology / Q000378:metabolism*; D018552:Daucus carota / Q000201:enzymology / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D005638:Fruit / Q000201:enzymology / Q000378:metabolism; D018551:Solanum lycopersicum / Q000201:enzymology / Q000378:metabolism; D008565:Membrane Proteins / Q000032:analysis / Q000378:metabolism; D010084:Oxidation-Reduction; D018087:Plastids / Q000201:enzymology / Q000378:metabolism*; D021381:Protein Transport; D020543:Proteome / Q000032:analysis*; D053719:Tandem Mass Spectrometry / Q000379:methods
chemical_list: D060365:Chloroplast Proteins; D008565:Membrane Proteins; D020543:Proteome; D002338:Carotenoids; D000255:Adenosine Triphosphate; D025222:Chloroplast Proton-Translocating ATPases