Potential of <i>Suaeda nudiflora</i> and <i>Suaeda fruticosa</i> to Adapt to High Salinity Conditions

The deposition of salts in soil seems likely to become a significant barrier for plant development and growth. Halophytes that flourish in naturally saline habitats may sustain extreme salt levels by adopting different acclimatory traits. Insight into such acclimatory features can be useful for devising salt-resilient crops and the reclamation of saline soil. Therefore, salinity-induced responses were studied in two halophytes, i.e., Suaeda nudiflora and Suaeda fruticosa, at a high soil salinity level (ECe 65) to explore their possible tolerance mechanisms in their natural habitat. Samples of different tissues were collected from both Suaeda species for the determination of physio-biochemical attributes, i.e., ionic (Na+, K+, Ca2+, Cl−) content, osmo-protective compounds (proline, soluble sugars, soluble proteins), total phenolic content, and antioxidant components. Heavy metal composition and accumulation in soil and plant samples were also assessed, respectively. Fourier transform infrared spectroscopy (FTIR) analysis was conducted to explore cellular metabolite pools with respect to high salinity. The results showed that both species considerably adjusted the above-mentioned physio-biochemical attributes to resist high salinity, demonstrated by quantitative differences in their above-ground tissues. The FTIR profiles confirmed the plants’ differential responses in terms of variability in lipids, proteins, carbohydrates, and cell wall constituents. The high capacity for Na+ and Cl− accumulation and considerable bioaccumulation factor (BAF) values for metals, mainly Fe and Zn, validate the importance of both Suaeda species as phytodesalination plants and their potential use in the phytoremediation of salt- and metal-polluted soils