A study on the effects of salinity on the growth and development of wheat and the improvement of its tolerance to salinity based on silicon

Salinity is the saltiness or amount of salt dissolved in a body of water, called saline water. Salinity is an important factor in determining many aspects of the chemistry of natural waters and of biological processes within it, and is a thermodynamic state variable that, along with temperature and pressure, governs physical characteristics like the density and heat capacity of the water. A contour line of constant salinity is called an isohaline, or sometimes isohale. Salinity is one of the most brutal environmental factors limiting the productivity of crop plants because most of the crop plants are sensitive to salinity caused by high concentrations of salts in the soil, and the area of land affected by it is increasing day by day. For all important crops, average yields are only a fraction – somewhere between ۲۰% and ۵۰% of record yields; these losses are mostly due to drought and high soil salinity, environmental conditions which will worsen in many regions because of global climate change. A wide range of adaptations and mitigation strategies are required to cope with such impacts. Efficient resource management and crop/livestock improvement for evolving better breeds can help to overcome salinity stress. However, such strategies being long drawn and cost intensive, there is a need to develop simple and low cost biological methods for salinity stress management, which can be used on short term basis. Microorganisms could play a significant role in this respect, if we exploit their unique properties such as tolerance to saline conditions, genetic diversity, synthesis of compatible solutes, production of plant growth promoting hormones, bio-control potential, and their interaction with crop plants. Silicon (Si) is the second most abundant element on Earth and is known as an important material to reduce the adverse effects of abiotic stresses. Salinity stress limits plant growth and productivity by severely affecting physiological processes. Silicon (Si) supplementation is considered as one of the promising methods to improve plant resilience under salt stress conditions. Here, the role of Si in modulating physiological and biochemical processes adversely affected by high salinity is discussed.