Abstract
Ozone is a natural and artificial chemical compound of Earth’s atmosphere. O3 is an absorbent of ultraviolet and infrared radiation and has strong oxidative properties. In the stratosphere the ozone layer protects the planet’s surface from dangerous UV radiation, its indirect effect on plant organisms is positive so stratospheric ozone can be called “good” ozone. The depletion of the ozone layer, as a result of atmosphere pollution, described as an ozone “hole” is causing UVB radiation enhanced level on Earth’s surface. The genetic, cytological, physiological and morphological reaction of prolonged UVB exposure in plants is twofold: it damages plants and simultaneously plants protect themselves and repair their injuries. The ozone in the troposphere originates from natural sources and is also a secondary pollutant, formed in photochemical reactions, leading to “smog” and ozone “spots” occurrence. As a strong oxidant, O3 is directly toxic to plants and can be recognized as “bad” ozone. Ozone is also classified as a “greenhouse” gas, participating in global warming. It is difficult to value the impact of O3 as a “greenhouse” gas on plants. The combined effect of O3 changes in the stratosphere and troposphere on plants can be estimated as loss in crop yield and in productivity of natural ecosystems