Effects of Salt Stress on Some Characteristics in Crop Plants

Salinity is a major environmental factor determining plant productivity and plant distribution. It affects more than 10 percent of arable land and salinization is rapidly increasing on a global scale, declining average yield for most major crop plants by more than 50 percent. Salt stress occurs in areas where soils are naturally high in salt and precipitation is low and/or where irrigation, hydraulic lifting of salty underground water, or invasion of sea water in coastal areas brings salt to the surface soil that inhabit plants. Salt tolerance in higher plants is regulated by a number of different physiological and biochemical processes. There is evidence that high levels of salt cause an unbalance of the cellular ions leading in both ion toxicity and osmotic stress. Basic metabolic pathways such as photosynthesis and respiration are affected by salinity. A response of respiration to salinity is primarily associated with the direct effects of salinity on enzyme function.
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