Application of Pressure Probe and UV-MALDI-TOF MS for Direct Analysis of Plant Underivatized Carbohydrates in Subpicoliter Single-Cell Cytoplasm Extract

Single-cell cytoplasm sap (1–10 pL) was extracted by using a pressure probe glass microcapillary tip from tulip leaf and bulb and analyzed by UV-MALDI-TOF MS for free underivatized carbohydrate content. Three matrices including 2,5-dihydroxybenzoic acid (DHB), 2,4,6-trihydroxyacetophenone (THAP), and carbon nanotubes (CNTs) in positive ion mode were selected for analysis because of acceptable carbohydrate-related signal reproducibility. Disaccharide and oligosaccharide (up to 15 Hex when THAP was used, 11 Hex with DHB, and 7 Hex with CNTs) were detected in tulip bulb cell cytoplasm sample. When DHB was used as matrix, neutral carbohydrates were more abundantly detected as sodiated cations; the sugar-related signals, however, appeared as dominant potassiated cations when THAP and CNTs were used. Small amount of monosaccharide was also detected in bulb cell cytoplasm with CNTs as matrix. UV-MALDI-TOF MS of leaf cell extract resulted in high-resolution detection of hexose and disaccharide with DHB, THAP, and CNTs.

Graphical AbstractSubpicoliter plant single-cell cytoplasm was sampled by Pressure Probe and its carbohydrate content successfully strait analyzed using DHB, THAP, and CNT as matrices in UV-MALDI-TOF-MS.Figure optionsDownload full-size imageDownload high-quality image (130 K)Download as PowerPoint slide