The variability of environmental conditions pared with the sessile lifestyle of plants contribute to high exposure to various stress factors. Increasing tolerance of crop plants to abiotic stresses is needed to fulfill increased food needs of the population. This book covers various aspects of abiotic stress tolerance in plants and presents methods to alleviate the harmful effects of stress factors. It provides information on how exogenous phytoprotectants can mitigate abiotic stressors including drought, elevated ozone, salinity, extreme temperatures, flooding, waterlogging, and toxic metals.