Plant Soil Environ., 2025, 71(5):320-337 | DOI: 10.17221/73/2025-PSE

Halophytic resilience in extreme environments: adaptive strategies of Suaeda schimperi in the Red Sea’s hyper-arid salt marshesOriginal Paper

Farag Ibraheem ORCID...¹, Mohammed Albaqami², Eman M. Elghareeb ORCID...³

¹ Umm Al-Qura University, Al-Qunfodah University College, Biology and Chemistry Department, Al-Qunfodah, Saudi Arabia

² Botany and Microbiology Department, College of Science, King Saud University, Riyadh, Saudi Arabia

³ Botany Department, Faculty of Science, Mansoura University, Mansoura, Egypt

Suaeda schimperi, a halophyte native to the Red Sea’s hyper-arid salt marshes, thrives in its extreme conditions (high salinity, minimal rainfall, and elevated temperatures). However, its adaptive tolerance mechanisms to these harsh conditions remain unclear. Herein, we investigated its growth responses and physiological mechanisms after short (5 days after treatment; DAT) and long-term (15 DAT) exposure to 0, 100, 200, and 400 mmol NaCl. Moderate salinity (200 mmol NaCl) enhanced growth, inducing 103.2% (5 DAT) and 40% (15 DAT) higher leaf biomass and 43.33% and 59.6% higher root biomass, respectively, compared to non-saline conditions. Deviation from moderate salinity reduced growth and disrupted ion balance, lowering K⁺, raising Na⁺, and increasing the Na⁺/K⁺ ratio, particularly under high salinity. The moderate salinity-enhanced growth was associated with increased chlorophyll, glycine betaine, glutathione, betacyanin, and betaxanthin, as well as higher antioxidant enzyme activity (polyphenol oxidase, peroxidase, catalase, ascorbate, and peroxidase) at 5 DAT. At 15 DAT, sugar accumulation and unsaturated fatty acids increased, while malondialdehyde and saturated fatty acids decreased. These findings reveal multiple adaptive strategies that support S. schimperi’s physiological stability under extreme environments and highlight its significance in ecological restoration and breeding salt-tolerant crops under escalating soil salinisation and climate change.

Keywords: osmotic stress; saline habitat; adaptation; salt tolerance

Received: February 23, 2025; Revised: April 28, 2025; Accepted: May 5, 2025; Prepublished online: May 23, 2025; Published: May 29, 2025  Show citation