|Wang, Yongqiang -|
|Fei, Zhangjun -|
|Yuan, Hui -|
|Mazourek, Michael -|
|Wang, Xiaowu -|
Submitted to: Journal of Experimental Botany
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 11, 2012
Publication Date: January 10, 2013
Repository URL: http://DOI: 10.1093/jxb/ers375
Citation: Wang, Y., Yang, Y., Fei, Z., Yuan, H., Fish, T., Thannhauser, T.W., Mazourek, M., Kochian, L.V., Wang, X., Li, L. 2013. Proteomic analysis of chromoplasts from six crop species reveals insights into chromoplast function and development. Journal of Experimental Botany. 64(4):949-961. Interpretive Summary: Chromoplasts are unique plastids that accumulate carotenoids, bringing vivid red, orange and yellow color to many flowers, fruits, and vegetables. Chromoplasts fulfill a variety of essential functions within the eukaryotic cells, and it is critical to comprehensively understand the metabolic processes and functions of chromoplasts as well as the mechanisms underlying their biogenesis and development. The provision of precise information on chromoplast proteomes will facilitate the endeavors. We performed proteomic and bioinformatic analyses of chromoplast proteins from six important crop species. The comparative analysis of chromoplast proteins reveals common metabolic characteristics shared among chromoplasts of different crop species and shows some remarkable difference of chromoplasts from specific crop species. Furthermore, the study highlights the crucial roles of energy production and transport in chromoplast development. This study provides large reference datasets for future experimental studies of chromoplast biogenesis, development and regulation in plants.
Technical Abstract: Chromoplasts are unique plastids that accumulate massive amounts of carotenoids. To gain a general and comparative characterization of chromoplast proteins, we 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 and analyzed using nLC-MS/MS. A total of 953 to 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 species. Seventeen core carotenoid metabolic enzymes were identified. Phytoene synthase, phytoene desaturase, zeta-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.