Mimosine-inhibited seed germination, seedling growth, and enzymes ofOryza sativa L.

The effect of mimosine (50 ppm and 100 ppm concentrations) onOryza sativa (rice) seed germination; root and shoot growth, i.e., length and fresh weight of seedlings; activities of nitrate reductase, peroxidase, catalase, and IAA oxidase were investigated. Significant inhibition in seed germination and shoot length was noted. Root length was inhibited by 100 ppm mimosine; however, the 50 ppm was not significant. Root and shoot fresh weight was not significantly inhibited by the tested concentrations of mimosine. Significant inhibition in activities of nitrate reductase, peroxidase and its isoenzymes, catalase, and IAA oxidase was observed. Ecophysiological implications of mimosine phytotoxicity are discussed.