Mechanism of Salinity Tolerance in Plants: Physiological, Biochemical, and Molecular Characterization

Abstract

Salinity is a major abiotic stress limiting growth and productivity of plants in many areas of the world due to increasing use of poor quality of water for irrigation and soil salinization. Plant adaptation or tolerance to salinity stress involves complex physiological traits, metabolic pathways, and molecular or gene networks. A comprehensive understanding on how plants respond to salinity stress at different levels and an integrated approach of combining molecular tools with physiological and biochemical techniques are imperative for the development of salt-tolerant varieties of plants in salt-affected areas. Recent research has identified various adaptive responses to salinity stress at molecular, cellular, metabolic, and physiological levels, although mechanisms underlying salinity tolerance are far from being completely understood. This paper provides a comprehensive review of major research advances on biochemical, physiological, and molecular mechanisms regulating plant adaptation and tolerance to salinity stress.

Morpho-physiological adaptation of Jatropha curcas L. to salinity stress

“…Currently, plant capacity to tolerate saline soil is of great importance, because the number of problems caused by soil salinity increases on a yearly basis. Estimates predict that a large portion of the world's irrigated areas are degraded due to salinization (FAO, 2011;Gupta and Huang, 2014). Salinity can negatively affect plant growth and crop yield, particularly due to the osmotic and toxic effects from saline ions (Niu et al, 1995;Munns and Tester, 2008;Munns, 2010).…”

“…Cell metabolism disturbances affect the photophosphorylation, respiratory chain, nitrogen assimilation and protein metabolism rates (Munns, 2002). Plant response to salinity is a complex phenomenon, so that, several studies have been carried out in order to elucidate the mechanisms used by plants to adapt to salt stress (Munns, 2010;Rahnama et al, 2011;Deinlein et al, 2014;Roy et al, 2014;Gupta and Huang, 2014). The salt-tolerance of a certain species depends on the efficiency of physiological mechanisms that make plants more tolerant to high salt concentrations (Flowers, 2004;Moya et al, 1999;Lacerda et al, 2003).…”

Zinc application mitigates the adverse effects of NaCl stress on mustard [Brassica juncea (L.) Czern & Coss] through modulating compatible organic solutes, antioxidant enzymes, and flavonoid content

“…Globally, high salinity affects over 20% of arable land; it exacerbates industrialization and urbanization in most parts of the world. However, poor irrigation practices are further aggravating the problem (Gupta and Huang 2014). Salinity stress hampers plant growth via diminishing cell division and expansion, reducing photosynthetic efficiency, modifying metabolic processes, as well as causing ion toxicity, osmotic stress, oxidative stress, genotoxicity, and other physiological disorders (Ibrahim et al 2012;Wani et al 2013;Yan et al 2013;Ahmad et al 2016b;Anjum et al 2015;Hussein et al 2017).…”

Applying hyperspectral imaging to explore natural plant diversity towards improving salt stress tolerance

“…Thus, the majority of crop species represent the glycophytes notwithstanding the conditions of saline soils (Gupta and Huang, 2014). The future prognosis is rather pessimistic: in 2050 the rising soil salinization will influence more than 50% of all arable land (Wang et al, 2003) which together with a growing world population may create a need to develop crops that are tolerant to salt stress.…”