Effect of Recurrent Salt and Drought Stress Treatments on the Endangered Halophyte Limonium angustebracteatum Erben

Abstract

Limonium angustebracteatum is an endemic halophyte from the Spanish Mediterranean coastal salt marshes. To investigate this species’ ability to cope with recurrent drought and salt stress, one-year-old plants were subjected to two salt stress treatments (watering with 0.5 and 1 M NaCl solutions), one water stress treatment (complete irrigation withholding), or watered with non-saline water for the control, across three phases: first stress (30 days), recovery from both stresses (15 days), and second stress (15 days). Growth and biochemical parameters were determined after each period. The plants showed high salt tolerance but were sensitive to water deficit, as shown by the decrease in leaf fresh weight and water content, root water content, and photosynthetic pigments levels in response to the first water stress; then, they were restored to the respective control values upon recovery. Salt tolerance was partly based on the accumulation of Na+, Cl− and Ca2+ in the roots and predominantly in the leaves; ion levels also decreased to control values during recovery. Organic osmolytes (proline and total soluble sugars), oxidative stress markers (malondialdehyde and H2O2), and antioxidant compounds (total phenolic compounds and flavonoids) increased by various degrees under the first salt and water stress treatments, and declined after recovery. The analysed variables increased again, but generally to a lesser extent, during the second stress phase, suggesting the occurrence of stress acclimation acquired by the activation of defence mechanisms during the first stress period.

Interactive Effects of Salinity Stress and Irrigation Intervals on Plant Growth, Nutritional Value, and Phytochemical Content in Mesembryanthemum crystallinum L.

“…These findings concur with the results reported by Alam et al [11] on Salsola imbricata (Fetid Saltwort), where the combined effect of salt and water stress on shoot length was not significant. However, these results contradict the findings of Calone et al [33] on Limonium angustebracteatum, where the individual effect of salt stress did not have a negative effect on leaf length but was remarkably affected by both factors. This suggests that the combined tolerance to drought and salinity could be species-specific among halophytes.…”

Elemental uptake and antioxidant activity in edible Mediterranean halophytes from Tinto River

“…In such habitats, synergistic effects of salinity with drought or flooding amplify the magnitude of applied stress, which in turn increased the synthesis of antioxidant compounds. Increasing sodium concentrations led to a significant and progressive proline and glycine accumulation in the aerial part of S. europaea (Calone et al, 2023). When comparing all halophyte species, the more salt-tolerant S. patula and A. macrostachyum accumulated relatively higher proline levels in response to salt stress.…”