一細胞からの植物ホルモンの「定量」に向けた取り組み

抄録

To understand the mechanisms by which plant hormones regulate physiological processes, it is crucial to exactly know their endogenous concentrations at cellular levels.　We recently established a method to determine the levels of abscisic acid （ABA） and jasmonoyl-isoleucine （JA-Ile） from single cells by employing “live-single cell mass spectrometry （MS）”.　Single cell contents were taken from Vicia faba leaves by using nano-electrospray ionization tips under a stereomicroscope.　Stable isotope-labeled hormones were then added to the samples as internal standards to normalize ionization efficiencies and quantify the hormone levels.　The samples were directly introduced into a mass spectrometer and subjected to MS/MS analysis.　With careful validation of the data obtained, we succeed in the detection of stress-induced accumulation of ABA and JA-Ile from living single cells.　In this article, we summarize our challenge to establish a method to quantify plant hormones by single cell MS analysis.