Physiological adaptive mechanisms of plants grown in saline soil and implications for sustainable saline agriculture in coastal zone

Abstract

There is large area of saline abandoned and lowyielding land distributed in coastal zone in the world. Soil salinity which inhibits plant growth and decreases crop yield is a serious and chronic problem for agricultural production. Improving plant salt tolerance is a feasible way to solve this problem. Plant physiological and biochemical responses under salinity stress become a hot issue at present, because it can provide insights into how plants may be modified to become more tolerant. It is generally known that the negative effects of soil salinity on plants are ascribed to ion toxicity, oxidative stress and osmotic stress, and great progress has been made in the study on molecular and physiological mechanisms of plant salinity tolerance in recent years. However, the present knowledge is not easily applied in the agronomy research under field environment. In this review, we simplified the physiological adaptive mechanisms in plants grown in saline soil and put forward a practical procedure for discerning physiological status and responses. In our opinion, this procedure consists of two steps. First, negative effects of salt stress are evaluated by the changes in biomass, crop yield and photosynthesis. Second, the underlying reasons are analyzed from osmotic regulation, antioxidant response and ion homeostasis. Photosynthesis is a good indicator of the harmful effects of saline soil on plants because of its close relation with crop yield and high sensitivity to environmental stress. Particularly, chlorophyll a fluorescence transient has been accepted as a reliable, sensitive and convenient tool in photosynthesis research in recent years, and it can facilitate and enrich photosynthetic research under field environment.

Saline stress enhanced accumulation of leaf phenolics in honeysuckle ( Lonicera japonica Thunb.) without induction of oxidative stress

“…ROS are able to bring about lipid peroxidation by initiating a chain reaction on polyunsaturated fatty acids, and MDA content representing the extent of lipid peroxidation is a classic parameter to reflect oxidative injury (Gill and Tuteja, 2010;Yan et al, 2013b). Fig.…”

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

“…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). Cumulatively, these adverse effects perturb growth and alter normal metabolism in plants (Wani et al 2013;Rasool et al 2013;Ahmad et al 2014;Iqbal et al 2015;Tang et al 2015;Hussein et al 2017).…”

Global plant-responding mechanisms to salt stress: physiological and molecular levels and implications in biotechnology

“…For glycophytes, high concentration salts can produce ionic stress, osmotic stress and secondary stresses (Zhu, 2002). In order to guarantee survival under such a detrimental circumstance, plants have evolved a series of biochemical and molecular processes to acclimatize themselves to the environment (Dufty et al, 2002;Glombitza et al, 2004;Jaleel et al, 2009;Yan et al, 2013). The specific biochemical strategy contains: (1) ion regulation and compartmentalization, (2) induced biosynthesis of compatible solutes, (3) induction of antioxidant enzymes, (4) induction of plant hormones and (5) changes in photosynthetic pathway (Parida & Das, 2005).…”