The effects of season and water availability on chemical composition, secondary metabolites and biological activity in plants

Plants react towards changes in their environment, which can be a result of biotic or abiotic activities. numerous studies have investigated the effects of abiotic stress on plants, and how it affects the primary as well as secondary metabolism. generally it is accepted that plants react to environmental stress by increasing secondary metabolites. this is however a very broad and simplified explanation and often inaccurate. various examples are provided where plants react positively, and often negatively towards seasonal variation and water availability, resulting in a lowering of certain secondary metabolites concentration, while others are increased. furthermore species differences, cultivars and interaction of other environmental factors such as temperature complicates a simple conclusion from the effect of stress on plants. the differential expression of genes in different species and in different metabolic pathways ensures a complex and very specific reaction of a plant to environmental stress. overall the paper provides support for a complex and intricate response system which differs for each plant species, and could be explained by understanding and studying the different metabolic pathways responsible for secondary metabolite production.