Proteomic analysis of salinity-stressed Chlamydomonas reinhardtii revealed differential suppression and induction of a large number of important housekeeping proteins
Salinity stress is one of the most common abiotic stresses that hamper plant productivity worldwide. Successful plant adaptations to salt stress require substantial changes in cellular protein expression. In this work, we present a 2-DE-based proteomic analysis of a model unicellular green alga, Chlamydomonas reinhardtii, subjected to 300 mM NaCl for 2 h. Results showed that, in addition to the protein spots that showed partial up- or down-regulation patterns, a number of proteins were exclusively present in the proteome of the control cells, but were absent from the salinity-stressed samples. Conversely, a large number of proteins exclusively appeared in the proteome of the salinity-stressed samples. Of those exclusive proteins, we could successfully identify, via LC–MS/MS, 18 spots uniquely present in the control cells and 99 spots specific to NaCl-treated cells. Interestingly, among the salt-exclusive protein spots, we identified several important housekeeping proteins like molecular chaperones and proteins of the translation machinery, suggesting that they may originate from post-translational modifications rather than from de novo biosynthesis. The possible role and the salt-specific modification of these proteins by salinity stress are discussed.
KeywordsAbiotic stress Chlamydomonas NaCl Proteomics Salt-specific proteins Salt stress
Two-dimensional gel electrophoresis
Liquid chromatography couple with tandem mass spectrometry
Reactive oxygen species
This work was conducted with funding in part from KURDI, Faculty of Science, Kasetsart University, Office of the Higher Education Commission and Thailand Research Fund grant # MRG5280035 to CY. KY thanks Thailand Research Fund, Office of the Higher Education Commission and Mahidol University for financial support.
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