Effect of sodium chloride on the response of the halophyte species Sesuvium portulacastrum grown in mannitol-induced water stress

Abstract

Sesuvium portulacastrum is a halophytic species well adapted to salinity and drought. In order to evaluate the physiological impact of salt on water deficit-induced stress response, we cultivated seedlings for 12 days, in the presence or absence of 100 mmol l(-1) NaCl, on a nutrient solution containing either 0 mmol l(-1) or 25 mmol l(-1) mannitol. Mannitol-induced water stress reduced growth, increased the root/shoot ratio, and led to a significant decrease in water potential and leaf relative water content, whereas leaf Na(+) and K(+) concentrations remained unchanged. The addition of 100 mmol l(-1) NaCl to 25 mmol l(-1) mannitol-containing medium mitigated the deleterious impact of water stress on growth of S. portulacastrum, improved the relative water content, induced a significant decrease in leaf water potential and, concomitantly, resulted in enhancement of overall plant photosynthetic activity (i.e. CO(2) net assimilation rate, stomatal conductance). Presence of NaCl in the culture medium, together with mannitol, significantly increased the level of Na(+) and proline in the leaves, but it had no effect on leaf soluble sugar content. These findings suggest that the ability of NaCl to improve plant performance under mannitol-induced water stress may be due to its effect on osmotic adjustment through Na(+) and proline accumulation, which is coupled with an improvement in photosynthetic activity. A striking recovery in relative water content and growth of the seedlings was also recorded in the presence of NaCl on release of the water stress induced by mannitol.

Morph-physiological responses to water deficit in parental genotypes of Medicago truncatula recombinant inbred lines

“…The development of the root system increases the water absorption and maintains the osmotic pressure. An increase in the root system under water stress has been reported in sunflower (Tahir et al, 2002), and in Sesuvium portulacastrum (Slama et al, 2007). Water deficit reduces the growth of leaves more compared to roots because the growth of roots and leaves exhibits different sensitivities to reduced Badri et al 1347 water availability (Verslues et al, 2006).…”

“…The reduction in the number as well as the biomass of leaves suggest that net CO 2 assimilation (A) per unit of leaf area is higher in plants subjected to drought stress than those grown in non-limiting conditions. Accordingly, Slama et al (2007) reported a decrease of number and size of leaves and an increase in net CO 2 assimilation in leaf growth rate per unit under water deficit in S. portulacastrum. This reduction saves water for the plant and is therefore considered as a criterion for adaptation to drought.…”

“…Author(s) agree that this article remains permanently open access under the terms of the Creative Commons Attribution License 4.0 International License changes in the structure of plants (Shao et al, 2008), the growth rate and gas exchange at the leaf level (Slama et al, 2007), and overproduction of compatible compounds (Nunes et al, 2008). One of the first responses to drought stress is stomatal closure (Anjum et al, 2011).…”

Effect of salt stress on some physiological parameters in <i>Atriplex halimus</i> L.

“…Work demonstrated in a halophyte Sesuvium portulacastrum increased sweating during salt stress [22]. [6] showed that the loss of water by transpiration increased mineral absorption in plants.…”

Sodium (Na+) and silicon (Si) coexistence promotes growth and enhances drought resistance of the succulent xerophyteHaloxylon ammodendron

“…This abiotic stress causes desertification coupled with a progressive decrease of vegetation coverage and rapid soil degradation in arid and semi-arid regions (Slama et al 2007;Ma et al 2012). Since most crops are highly susceptible to drought, xerophytes, such as Haloxylon ammodendron (C. A.…”