Physiological response of halophytes to multiple stresses

Abstract

As halophytes grow vigorously in saline soils, they serve as extraordinary resources for the identification and development of new crop systems. Understanding the mechanisms of tolerance of halophytes to salinity in combination with other co-occurring constraints such as drought, flooding, heavy metals and nutrient deficiencies, would facilitate efforts to use halophytes for saline land revegetation, as well as provide new insights that might be considered in future breeding of plants for salt-affected agricultural lands. Recent results suggest that salinity may improve the response of halophytes to other stresses. Some physiological and biochemical mechanisms of tolerance to salinity are common to many halophytes when plants are subjected to salinity, whereas others are specifically amplified under a combination of stresses. Therefore, the response of halophytes to multiple stresses may not reflect an additive effect of these constraints, but rather, constitute specific response to a new situation where many constraints are operating simultaneously. Comparative studies between halophytes and glycophytes have shown that halophytes are better equipped with the mechanisms of cross-stress tolerance and are constitutively prepared for stress. Moreover, other data has shown that the pre-treatment of halophytes with salinity or other constraints in the early stages of development improves their subsequent response to salinity, which suggests the capacity of these plants to ‘memorise’ a previous stress allows them respond positively to subsequent stress.

Phytochemical and Biological Activities in Limonium Species Collected in Different Biotopes of Tunisia

“…It was well-known tolerance to salinity and drought as often positively correlated with an effective antioxidant system. [21,[25][26][27] The halophyte species studied in this work were native of stressful biotopes and have acquired adaptation strategies, particularly against oxidative stress, by high activity of antioxidant enzymes if compared to glycophytes plants. Thus, our results suggested that L. vulgare, native to Oued Rane, had a cell protection better than other species by the high SOD activity.…”

SOS1, HKT1;5, and NHX1 Synergistically Modulate Na+ Homeostasis in the Halophytic Grass Puccinellia tenuiflora

“…One of the major consequences of salt stress is a disruption of Na + and K + homeostasis in both cellular and whole-plant levels, accompanied by membrane dysfunction and attenuation of cellular metabolism, resulting in the inhibition of cell division, growth, photosynthesis, and development (Omielan et al, 1991; Flowers, 1999; Horie and Schroeder, 2004; Yan et al, 2013; Duan et al, 2015). To avoid Na + toxicity, plants have evolved various adaptation mechanisms, such as restricting Na + uptake from environments, extruding cytoplasmic Na + to the outside of the cell and sequestering Na + into vacuoles to reduce Na + accumulation in cytosol (Wang et al, 2007; Hamed et al, 2013). …”

Growth, sodium uptake and antioxidant responses of coastal plants differing in their ecological status under increasing salinity

“…In salt deserts of the arid and semiarid regions, particularly at Chott and Sebkhas, soil is a source of salt particles easily carried by the wind towards the land and surrounding cultures (Mtimet 2001). Thus, plants in these environments have certainly acquired characteristics to adapt to soils whose chemical composition varies in time and space, depending on salinity and associated stress (Ben Hamed et al 2013). Therefore, the adaptations of these coastal plants are complex and varied.…”