Abiotic Stress

Abstract

The conditions which allow plants to attain maximal growth and reproductive potential, as determined by their total biomass (comprising of plant height, weight, and seed number), can be considered as the ideal growth conditions for the particular plant. Since plants grow and reproduce in complex environmental conditions composed of a multitude of abiotic and biotic factors, they are frequently exposed to stress conditions. Stress can be described as environmental conditions which prevent plants from attaining their full genetic potential, and, hence, it adversely affects plant growth, development, and productivity. Environmental factors which result in stress may be divided into biotic and abiotic. Biotic stress is imposed by direct or indirect interactions with other organisms, whereas abiotic stress originates from excess or deficit in the physical, chemical, and energetic conditions to which plants are exposed. Environmental conditions which have deleterious effect on plants include drought, flood, excessive soil salinity, high or low temperature, excess or insufficient light, and inadequate mineral nutrients. Phytotoxic molecules, like ozone, can also cause damage to plant tissues. Stress affects numerous plant responses ranging from changes in cellular metabolism and gene expression to modulation of growth rate and crop yield. The response of a plant is influenced by the severity, duration, and rate at which stress is imposed. A single stress or a combination of varied stress conditions can result in different stress responses. Moreover, plant responses can be elicited directly by stress or indirectly through stress-induced injury. Various factors, such as genotype, developmental stage, species, and organ or type of tissue, influence the sensitivity or resistance of plants to stress condition(s).