Stomatal Action in Plants as Related to Damage From Photochemical Oxidants

Abstract

A review of the literature indicates that the sto-mates of leaves must be open for smog damage to oc-cur (3, 7, 8, 9, 11). However, there is no direct re-lationship between degree of opening and extent of injury, nor has it been proven that injury is prevent-ed when the stomates are closed. Moreover, most of the earlier work dealt with the reaction product of ozone and gasoline or ozone and an olefin (8,10,16). Such reaction products are unstable and do not nor-mally accumulate in a polluted atmosphere to a level sufficient to cause plant damage (1, 4). The results of this study indicate that under the conditions of the experiments, stomatal opening is not the primary controlling factor in predisposing plants to injury from ozone and peroxyacetyl nitrate (PAN), two phytotoxic products in smog.