Perspectives of Salinity Tolerance of Some Crops: A Review Rodríguez Humberto González1,*, Maiti R.K.2,** 1Facultad de Ciencias Forestales, Universidad Autónoma de Nuevo León, Apartado Postal 41, Linares, NL, 67700, Mexico. 2Vibha Seeds, Vibha Agrotech Ltd, Inspire, Plot#21, Sector 1, Huda Techno Enclave, High Tech City Road, Madhapur, Hyderabad-500081, Andhra Pradesh, India. *E-mail: humberto@fcf.uanl.mx
**ratikanta.maiti@gmail.com
Abstract Salinity affects crop productivity in one-fifth part of irrigated agriculture in the world. A brief review has been made on salt tolerance of some field and vegetable crops including major cereals, sunflower and cotton. Sufficient research inputs have been directed on research on salinity in different areas such as ameliorations, its effects on growth and productivity, physiological and biochemical changes, its mechanism of resistance and biotechnology. This review gives a brief account of the adavances on salinity tolerance in several crops viz. sorghum, pearl millet, maize, rice, wheat, sunflower, cottons and some vegetable crops. Increasing salinity decreases germination, emergence, seedling establishment, growth and crop productivity. In general, salinity stress causes physiological and biochemical changes depending on crops such as decrease in relative growth rates, K concentrations and leaf osmotic potential values, as well as an increase in Na, soluble sugar contents, proteins, amino acids, proline, glycine betaine, and other osmolytes which help in osmotic adjustment. There are several antiporters (proteins) present in cell membrane such as Na+/H+, Na+/K+ operating which does not allow Na+ and exclude it, but permits K+ or H+ to enter thereby maintaining balance. Among the most common effects of salinity is the growth inhibition by Na+ toxicity. Vacuolar Na+/H+ antiporters have been suggested to be involved in sequestering Na+ into vacuoles, thus preventing toxic effects of Na+ in the cytoplasm. Compartamentation and sequestring of Na+ and Cl‐ in the vacuole increases osmotic pressure in the cell. A major component of tissue tolerance is the capacity to compartmentalize salt into safe storage places such as vacuoles. This mechanism would avoid toxic effects of salt on photosynthesis and other key metabolic processes. The maintenance of photosynthetic capacity (and the resulting greater salt tolerance) at higher leaf Na+ levels is associated with the maintenance of higher K+, lower Na+ and the resulting higher K+:Na+ in the cytoplasm of mesophyll cells. It has been reported that the response of salinity tolerance appears similar to that of water stress. Salt tolerant plants differ from salt-sensitive one for low rate of Na+ and Cl‐ transport to leaves, and the ability to compartmentalize these ions in the vacuoles thereby preventing their accumulation in the cytoplasm and avoiding toxicity and metabolic disorder. Top Keywords Salt tolerance, salinity, crops, genotypic variability, amelioration, osmotic adjustment, biotechnology. Top |