Seven toxic substances to rice seedlings were isolated from the cultured cell suspension of X. campestris pv. oryzae and they were identified as 3-methylthiopropionic acid, trans-3-methylthioacrylic acid, phenylacetic acid, isovaleric acid, tiglic acid, succinic acid and fumaric acid by means of UV-, IR-, NMR- and Mass-spectroscopy and of elementary analysis.
