Plant response to integrated impact of natural and anthropogenic stress factors

Abstract

Responses of cultivated plants (Lepidium sativum L. and Lycopersicon esculentum Mill.), i.e., changes in growth characteristics, pigment and proline content, to an integrated impact of natural (temperature) and anthropogenic (substrate acidity, population density, and heavy metals) stress factors were studied under controlled environmental conditions. The experiments were carried out in a phytotron (tomato) and under laboratory conditions (garden cress). The external stress factors produced a general suppression of growth and pigment synthesis and differentially affected individual biological characteristics of the plants. Each of the stress factors narrowed the interval of plant tolerance to other stress factors. Strong impact of one stress factor affected plant homeostasis mechanisms by weakening plant response to other stress factors.