Determination of single-cell gene expression in Arabidopsis by capillary electrophoresis with laser induced fluorescence detection

We report a new method for the measurement of gene expression in single cells of Arabidopsis using capillary electrophoresis with laser-induced fluorescence (CE–LIF) detection. Initially, the quantitative analysis of APETALA2 (AP2) and LEAFY (LFY) was performed by CE–LIF method. The detection limits of AP2 and LFY can reach 0.08 and 0.04 ng/ml (signal-to-noise ratio = 3), respectively. This protocol coupling with single-cell reverse transcriptase-polymerase chain reaction (SC-RT-PCR) has been used to monitor LFY and AP2 expression in individual cells from the shoot apical meristem, leaf, root, and stem of Arabidopsis, simultaneously. The effect of PCR cycle number on PCR product concentrations has been discussed. The changes of LFY expression were determined at single-cell level in different Arabidopsis tissues. The relationship between gibberallic acid (GA) and LFY expression was also revealed by this method. It was shown that the combination between CE–LIF and SC-RT-PCR could provide a highly sensitive and selective tool for the determination of different gene expression at single-cell level in specific tiny plant tissues.