Figure 4

Illustrated workflow of on-site cell metabolomics in cellular fluids extracted from a single pollen grain located under the anther wall in intact plants which are exposed to heat conditions. The upper and lower insets in (A) shows a simple schematic of tip insertion into pollen on the anther cross section and anther side view, respectively. (A) shows a schematic of the fluid extraction and the microscopic image taken at the extraction. As soon as the cellular fluid was expelled into the capillary and the boundary (meniscus) was formed between the oil and cell sap, the tip was put into the water drop of ultrapure water for dilution (B). And then, the probe tip was immediately removed from the water drop and rotated 180° using a 3D move/rotation micro-manipulator. And instantly, the metabolites in the fluids were analyzed in Orbitrap mass spectrometer by applying a high voltage without any pre-treatment (C, see Methods).