Monitoring OsRac1 activation after treatment of rice protoplasts with the MAMP chitin. Time-lapse imaging of rice protoplasts expressing Raichu-OsRac1-WT after chitin treatment. Red line, 0.5 μg/ml chitin treatment; blue line, W5 buffer treatment. The FRET images are shown in IMD mode, which associates colour hue with emission ratio values and the intensity of each hue with the brightness of the source image. Bars: 5 µm.