Fig. 1

FDA and PI staining of plant cells. a Diagrams showing fluorescein diacetate (FDA) and propidium iodide (PI) staining of plant cells. Top: Non-fluorescent FDA molecules pass through the intact plasma membrane and are hydrolyzed by intracellular esterases to produce fluorescein. The membrane-impermeable fluorescein accumulates in the cytoplasm and exhibits green fluorescence. Bottom: In a non-viable cell with a disrupted plasma membrane, PI enters the cell and intercalates with DNA to form a bright red fluorescent complex in a nucleus. PI also stains the cell wall in both live and dead cells. b Single plane confocal images of rice sheath epidermal cells (top) and immediately underlying mesophyll cells (bottom) stained with both FDA (green) and PI (red). Bar = 20 μm. c Time-course average pixel intensity of FDA-stained rice sheath epidermal cells. Blue line is an average ± SD of intensity measurements of defined regions of cytoplasmic fluorescence (n = 6 at each time point). Fluorescein intensity peaked on average at 15 min after staining and then steadily declined