Cell ploidy levels are regulated by developmental and environmental factors and they also impact the outcome of plant microbe interactions. Here we describe a simple and quick procedure to measure cell ploidy levels in Arabidopsis thaliana leaves by flow cytometry. Cell nuclei are isolated by filtering tissue homogenates from chopped plant tissues. DNA in the nuclei is stained by propidium iodide and the fluorescence emitted from the DNA of each nucleus is read by using a flow cytometer. Distribution of ploidy levels within the plant tissues can be calculated based on the distribution of fluorescence signals. Multiple samples can be prepared and analyzed within the same day.
Keywords: Arabidopsis thaliana; Cell cycle; Flow cytometry; Ploidy; Propidium iodide.