Interaction Between UV-B Radiation and Other Stresses in Plants

Abstract

Over 100 plant species and cultivars have been screened for sensitivity to UV-B radiation and these have displayed a wide range of responses. Yet despite this large body of information, we are still not at a point where we can make reliable quantitative or even qualitative estimates of the potential impact of enhanced levels of UV-B radiation resulting from a partial stratospheric ozone depletion. The primary reason for this dilemma is that nearly all of our biological effects information comes from controlled environment experiments (i.e., greenhouses and growth chambers). In such facilities UV-B radiation is supplied to plants while most other environmental variables such as temperature, water supply and nutrients are optimized for plant growth. Such ideal growth conditions rarely are found in nature. In fact, since most environmental factors co-vary, it: would not be uncommon for plants in the field to experience several stresses concomitantly. The interaction between UV-B radiation and other stresses may produce a combined response which differs either antagonistically or synergistically from either stress independently. Such combined effects will be examined between UV-B radiation and plants grown under limiting conditions of visible radiation, water, and nutrients.