Spontaneous ultraweak, bioluminescence in plants: Origin, mechanisms and properties

An analysis of theoretical knowledge and experimental results of ultraweak luminescence (UWL) is provided. The role of excited state of molecules and free radicals, formed in various biochemical reactions, in UWL is discussed . UWL of model reactions and in vivo systems are compared. The hypothesis o f coherent electromagnetic field as a source of UWL is also discussed. Spec tral, kinetic and temporal properties of UWL are summarised, as well as the ir connection with its origin and role in the organism. Attention is paid t o recent progress in experimental methods of low-light detection. The possi ble use of UWL in environmental studies, selection and other applications i s discussed.