Chemiluminescence in Wounded Root Tissue

Root and stem segments from soybean (Merrill cv. ;Bragg') showed an enhanced chemiluminescence upon mechanical injury. Roots emitted more light than did stems. Light emission was diminished by CN(-) and N(3) (-) but was not affected by rotenone and antimycin A. Catalase quenched chemiluminescence in wounded root segments as did ascorbic acid and hydroquinone. Superoxide dismutase addition resulted in a small diminution in light emission, but mannitol, an OH. scavenger, was without effect. The addition of H(2)O(2) to wounded root segments markedly elevated chemiluminescence in the presence of air as well as under N(2). It is concluded that peroxidases, found abundantly in roots, predominantly contribute to light emission in wounded plant tissue.