Plant DNA Analysis: Estimation of Nuclear DNA Content in Plant Homogenates

Flow cytometry (FCM) provides a rapid, accurate, and simple means to determine plant homogenates’ nuclear DNA content (C value). It has been used extensively for large-scale studies of ploidy levels in plants growing in the field or greenhouses. The method involves staining plant cells directly with a DNA-binding dye such as propidium iodide (PI) in a hypotonic sodium citrate buffer and then analyzing the stained cells by flow cytometry to generate high-quality histograms of DNA content. However, one challenge in applying this technique to plants has been the presence of various cytosolic compounds that can interfere with the PI fluorescence signal. To address this issue, researchers have developed a modified hypotonic citrate buffer containing antioxidants that can reduce the adverse effects of these compounds, making the PI buffer suitable for nuclei extraction from plants. The resulting method is quick, requires minimal material, and is highly versatile for analyzing plant tissues for DNA content in an unknown sample. The calculated 2C value can be helpful in genome research and studies of the relationship between DNA content, plant science, and ecology. It can also provide valuable information for next-generation sequencing efforts to accelerate the domestication of valuable crops. Flow cytometry is a powerful and widely used technique in plant research, with potential applications for studying plant genetics, evolution, and ecology.