Spontaneous ultraweak photon emission from rice (Oryza sativa L.) and paddy weeds treated with a sulfonylurea herbicide

All living organisms spontaneously generate ultraweak photon emissions, which originate from biochemical reactions in cells. Current research uses the ultraweak photon emissions from organisms as a novel tool to investigate the physiological states of plants. In this study, we found ultraweak photon emissions from leaf segments of rice and several paddy weed species treated with a sulfonylurea herbicide. There is a definite difference in photon emissions among plant species, and rice (Oryza sativa), barnyardgrass (Echinochloa crus-galli) and Cyperus serotinus showed extremely strong enhancement of photon emissions. Photon emissions from these three species treated with sulfonylurea herbicide were suppressed when the leaf segments were treated with the cytochrome P450 monooxygenase (P450) inhibitors, piperonyl butoxide and malathion. These results suggest that P450 inhibitors affect the ultraweak photon emissions from plants.