Abstract
BackgroundEpidermal bladder cells (EBC) are large single-celled, specialized, and modified trichomes found on the aerial parts of the halophyte Mesembryanthemum crystallinum. Recent development of a simple but high throughput technique to extract the contents from these cells has provided an opportunity to conduct detailed single-cell-type analyses of their molecular characteristics at high resolution to gain insight into the role of these cells in the salt tolerance of the plant.ResultsIn this study, we carry out large-scale complementary quantitative proteomic studies using both a label (DIGE) and label-free (GeLC-MS) approach to identify salt-responsive proteins in the EBC extract. Additionally we perform an ionomics analysis (ICP-MS) to follow changes in the amounts of 27 different elements. Using these methods, we were able to identify 54 proteins and nine elements that showed statistically significant changes in the EBC from salt-treated plants. GO enrichment analysis identified a large number of transport proteins but also proteins involved in photosynthesis, primary metabolism and Crassulacean acid metabolism (CAM). Validation of results by western blot, confocal microscopy and enzyme analysis helped to strengthen findings and further our understanding into the role of these specialized cells. As expected EBC accumulated large quantities of sodium, however, the most abundant element was chloride suggesting the sequestration of this ion into the EBC vacuole is just as important for salt tolerance.ConclusionsThis single-cell type omics approach shows that epidermal bladder cells of M. crystallinum are metabolically active modified trichomes, with primary metabolism supporting cell growth, ion accumulation, compatible solute synthesis and CAM. Data are available via ProteomeXchange with identifier PXD004045.Electronic supplementary materialThe online version of this article (doi:10.1186/s12870-016-0797-1) contains supplementary material, which is available to authorized users.
Highlights
Epidermal bladder cells (EBC) are large single-celled, specialized, and modified trichomes found on the aerial parts of the halophyte Mesembryanthemum crystallinum
We carry out large-scale complementary quantitative proteomic studies using both a label and label-free approach to identify salt-responsive proteins in the EBC extract
Quantitative proteomic analysis To identify salt-responsive proteins in EBC extracts, a study combining complementary two dimensional differential in-gel electrophoresis (2D-DIGE) and 1D-PAGE with label-free LC-Liquid chromatography-tandem mass spectrometry (MS)/MS (GeLC-MS/MS) based quantification methods was performed to compare proteins in extract from salt-treated plants to EBC extract from untreated control plants with the aim to maximize the coverage of the proteome
Summary
Epidermal bladder cells (EBC) are large single-celled, specialized, and modified trichomes found on the aerial parts of the halophyte Mesembryanthemum crystallinum. Trichomes are highly differentiated cell types found on the aerial epidermis of most plants These specialized cells vary morphologically and functionally, with roles in plant defence, stress tolerance, water collection, seed dispersal and leaf structure. They can range from simple unicellular hair-like extensions to multicellular complex appendages [2, 3]. Halophyte plant species have evolved several different types of trichomes ranging from bi- or multi-cellular glands of the Poaceae, which actively excrete salt [6], to non-glandular (non-secreting) trichomes called epidermal bladder cells (EBC) These EBC are attached to either the epidermis via stalk cells, as in the Chenopodiaceae [7], or stalk-less as in the Mesembryanthemaceae [8]. The diameter of EBC can be 1 mm with an average cell volume of 500 nl; volumes in excess of 5 μl have been reported [8, 9]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
