膀胱表皮细胞(EBC)是大的单细胞细胞,专业,以及在盐生植物中胚层的地上部分发现的改良毛状体。从这些细胞中提取内容物的简单但高通量技术的最新发展提供了以高分辨率对其分子特征进行详细的单细胞型分析的机会,以深入了解这些细胞在植物耐盐性中的作用。
在这项研究中,我们使用标记(DIGE)和无标记(GeLC-MS)方法进行大规模互补定量蛋白质组学研究,以鉴定EBC提取物中的盐响应蛋白。此外,我们进行了离子组学分析(ICP-MS),以跟踪27种不同元素的含量变化。使用这些方法,我们能够鉴定出54种蛋白质和9种元素,这些蛋白质和元素在盐处理的植物的EBC中显示出统计学上的显着变化。GO富集分析确定了大量的转运蛋白,但也涉及光合作用的蛋白质,初级代谢和Crassulacean酸代谢(CAM)。通过蛋白质印迹验证结果,共聚焦显微镜和酶分析有助于加强研究结果,并进一步了解这些特化细胞的作用。正如预期的那样,EBC积累了大量的钠,然而,最丰富的元素是氯化物,表明将该离子隔离到EBC液泡中对于耐盐性同样重要。
这种单细胞类型组学方法表明,微晶M.的表皮膀胱细胞是代谢活性修饰的毛状体,初级代谢支持细胞生长,离子积累,兼容的溶质合成和CAM。数据可通过具有标识符PXD004045的ProteomeXchange获得。
Epidermal 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.
In 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.
This 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.