Stress and Secondary Metabolism in Cultured Plant Cells

Abstract

Grime1 defines “stress” in plants as the external constraints which limit the rate of dry matter production of all or part of the vegetation, e.g. shortages of water, light, mineral nutrients and suboptimal temperatures. These shortages may be an inherent characteristic of the environment, or they may be induced or intensified by the vegetation itself. The use of the word “stress” to describe an external constraint on dry matter production differs from that of many plant physiologists however, who have used the word to describe the physiological state of the plant. Grime’s definition could be applied to cultured plant cells; stress in this case would be any type of constraint which reduces the dry matter of the cultures. This otherwise excellent and precise definition is not very useful, however, to phytochemists who are generally not interested in dry matter production. We will define stress as the external constraints on cultured cells which limit the normal production of secondary metabolites. Let us call this phytochemical stress to be absolutely specific.