Altered water relations, selective nutrient uptake, and reduced Na+ flux make Halopeplis perfoliata an obligate halophyte

Abstract

Halopeplis perfoliata, a succulent halophyte of coastal marshy habitats, was grown in a greenhouse to study its adaptive responses in terms of growth, osmoregulation and N-metabolism following one-month exposure to salinity (0, 150, 300 and 600 mmol L -1 NaCl). Biomass was optimal in 150 mmol L -1 NaCl with unaltered malondialdehyde (MDA) levels. Whereas, biomass remained comparable to non-saline control with some increase in MDA in 300 and 600 mmol L -1 NaCl. Osmotic potential (ψ S ) was maintained up to 300 mmol L -1 NaCl that correlated with increase in succulence (SC) and lower water deficit (WD). Whereas, sap ψ S was lowest in 600 mmol L -1 NaCl along with lower SC and high WD. Sodium level gradually increased in shoot and was higher than the root. Potassium deficiency was not observed up to high salinity. Both soluble sugars and nitrogen isotope (δ 15 N) increased transiently in 300 mmol L -1 NaCl. Hence, modulations in water relation, selective nutrient uptake and controlled Na + flux appear important for salinity tolerance of H. perfoliata.

Alternative electron sinks in chloroplasts and mitochondria of halophytes as a safety valve for controlling ROS production during salinity

“…TBARS increases in environmental stresses as a result of oxidative stress. This holds true as well for salt stress in halophytes (Amor et al, 2006(Amor et al, , 2007Ben Amor, 2010;Hassine et al, 2008;Karakas ¸et al, 2017;Koyro et al, 2013;Li, 2008;Rasool et al, 2021;Sai Kachout et al, 2011;Takagi and Yamada, 2013;Wang et al, 2004;Yildiztugay et al, 2014). Interestingly, in some studies dealing with halophytes, TBARS concentrations were low and stayed that way (Zouhaier et al, 2015) or continued to decrease (Slama et al, 2017) Rigidification caused by an increase in saturation of membrane fatty acids is also thought to decrease salt permeability (Zhukov and Shumskaya, 2020), making it a more general tolerance response and thus giving more credence to this hypothesis.…”

Ecophysiological and Biochemical Responses Depicting Seed Tolerance to Osmotic Stresses in Annual and Perennial Species of Halopeplis in a Frame of Global Warming

“…Some earlier studies have reported different ecological aspects of the seed germination of the Halopeplis species individually [20][21][22][23][24]. However, a comparison of the osmotic stresses and biochemical aspects of the seed germination of the Halopeplis species has not been done.…”