1D-O1-1445 PDF
Pressure probe electrospray ionization for one cell metabolite/protein analyses
Directly sampled cell solution can be ionized for MS analysis by applying high voltage to the solution inside a tip of the capillary of the pressure probe containing silicon oil mixed with a small amount of ionic liquid. Trichomes are unicellular or multicellular outgrowths originating from the aerial epidermal cells of stems, leaves, floral organs and fruits. In Solanum spp., they are typically classified into eight distinct types based on their morphological appearance. Some types of trichomes are known to synthesize and accumulate specialized metabolites such as acylsugars, flavonoids and terpenoids. Their contents may vary transiently through developmental stages of plants. Monitoring the physicochemical and metabolic properties of individual trichome cells is, therefore, a potential means to provide diagnostic clues for physiological status of crop plants. Metabolite profiling in intact single cells from different types of trichomes in tomato plants is shown by using a pressure probe electrospray ionization mass spectrometry (PPESI-MS) system. Proteins in tomato trichomes can be also analyzed in PPESI-MS. Additionally, real time pressure probe operation is shown in rice grains for rice chalky ring formation caused by temporal reduction in starch biosynthesis during osmotic adjustment under foehn-induced dry wind.