Differences in physiological responses to NaCl between salt‐tolerant Sesbania rostrata Brem. & Oberm. and non‐tolerant Phaseolus vulgaris L.

Abstract

Sesbania rostrata ( S. rostrata) Brem. & Oberm., a member of the Fabaceae family, has been used as a promising halophytic plant to ameliorate soil salinity in north-east Thailand. To obtain information regarding the mechanism of salt tolerance, the physiological responses of S. rostrata to NaCl was compared with those of the salt-susceptible species, kidney bean ( Phaseolus vulgaris L. cv. Meal). Seedlings were grown hydroponically with 0, 50, 100 and 150 m  NaCl for 10 days and their effects on growth, chlorophyll content, fluorescence yield ( F v / F m ), inorganic elements and amino acid content were determined. The results showed that tolerance to NaCl was clearly different between the two plants. At the highest concentration (150 m  ), the dry weight of S. rostrata was more than 50% greater than the control, whereas the kidney bean could not survive. Chlorophyll a content drastically reduced only in the kidney bean. The F v / F m of S. rostrata did not change with increasing concentrations of NaCl, but that of kidney bean decreased. Greater percentages ( ≥ 80%) of absorbed Na + and Clwere translocated and accumulated in the shoots of S. rostrata , but remained largely in the roots of kidney bean. The enhancement of contents of amino acids, including proline, with increasing NaCl was observed in both species. These results strongly suggest that the salt tolerance of S. rostrata is associated with the ability of the plant to translocate and sequester Na + and Clin the shoot cells.

Antioxidative enzymes response to NaCl stress in salt‐tolerant Sesbania rostrata

“…Seeds of S. rostrata and Phaseolus vulgaris L. cv. Meal were germinated at 25°C for 2 days in darkness and grown hydroponically as reported earlier ( Jungklang et al . 2003).…”

“…1998). Our previous study ( Jungklang et al . 2003) suggested that salt tolerance of S. rostrata to NaCl was related to the plant's ability to translocate Na + and Cl – from roots to shoots and trap them in the shoot cells.…”

Potential Use of Alluvial Groundwater for Irrigation in Arid Zones - Mhamid Oasis (S Morocco)

“…The ions of Na + have similar impact -their excess leads to disruptions in ionic balance in plants and limited intake of other ions that are crucial for proper plant growth [26]. Too high levels of Na + and Cl -ions result in such a significant change of chemical composition of soils solution that is disrupts also the intake of nutrients that are crucial for plants life, like magnesium, nitrogen and phosphorus [27][28][29]. The excess of sodium ions in soil solution is accompanied by calcium deficiency in plants, because as a result of ion exchange it may be removed from the environment of the roots.…”

Elucidation of Abiotic Stress Signaling in Plants

“…There exists a differential pattern of accumulation and/or partitioning of Na + and Cl − in plants (Zhao et al 2002 ), and their effects on growth and leaf area (Maggio et al 2007 ). Nevertheless, the accumulation and partitioning of Na + and Cl − in salinity-treated plants can be genotype dependent (Jungklang et al 2003 ;Garg and Singla 2004 ). Na + and/or Cl − preferentially accumulates in roots over shoots via salt tolerance (salt exclusion) mechanism and thereby maintains a substantial potential for osmotic water uptake into the roots by restricting the spread of Na + to shoots (Chartzoulakis et al 2002 ;Aydi et al 2008 ).…”