ABSTRACT
Global changes in environmental conditions, mainly caused by anthropogenic activities, are a consequence of increased carbon dioxide (CO2), leading to modification in ozone, high light intensity, and temperature extremes. Plants respond to these abiotic stressors by altering their metabolism in order to maintain metabolic homeostasis and to produce compounds that ameliorate the stress. Plants synthesize a variety of secondary metabolites that are provoked by a variety of abiotic factors, such as drought, salinity, light intensity, temperature, and cold stress, to cope with environmental changes. Various plant metabolites, such as polyamines, flavonoids, jasmonic acid, methyl jasmonate, glycine, and betaine, play a defensive role under abiotic stress conditions. Moreover, plants have been transformed to generate various metabolites that are species-specific and are dependent on environmental factors. In order to overcome numerous stresses, plants implement various approaches, including accumulation or adjustment of compatible solutes and scavenging of stress-induced reactive oxygen species (ROS) by the production of antioxidants to maintain membrane stability. This chapter illuminates the pivotal role of plant metabolites and their adaptation strategies, with special note of the role of secondary metabolites in coping with major universal changes, such as elevated temperature, waterlogging, light intensity, salinity, heavy metals, drought, and cold.
