NaCl‐induced changes in protoplasmic characteristics of Hordeum vulgare cultivars differing in salt tolerance

Abstract

Water permeability and cytoplasmic viscosity and streaming were investigated in seedlings of two Hordeum vulgare cultivars differing in salt tolerance. Six‐day‐old seedlings were grown for 4 additional days in Hoagland solution with and without 100 mM NaCl added. Observations and measurements were made in subepidermal cells of the coleoptile using plasmolytic and centrifugation methods and recordings of the speed of movement of microsomes. Water permeability was about the same in controls of both cultivars, and was decreased by NaCl stress, but decreased less in the tolerant cultivar. Cells from control plants of the stress tolerant variety had a higher cytoplasmic viscosity than cells from the moderately sensitive cultivar. Cytoplasmic viscosity in both cultivars decreased due to NaCl stress, and more so in the sensitive one. Cytoplasmic streaming was faster in the controls of the salt sensitive cultivar than in controls of the salt tolerant cultivar; NaCl had no significant effect on cytoplasmic streaming in both cultivars. The specific responses of the cytoplasm of the sensitive and tolerant cultivars to the salt treatment reflect differences in its structure and composition. These differences in the cytoplasm already exist before exposure to salt stress but some alterations of cytoplasmic parameters (e.g. water permeability) were induced by the saline environment.

Abiotic Stress Signaling in Wheat – An Inclusive Overview of Hormonal Interactions During Abiotic Stress Responses in Wheat

“…Similar to drought stress, high salinity also induces high levels of reactive oxygen species (ROS) that damage various cellular functions ( Apel and Hirt, 2004 ). Notably, increased salinity affects membrane permeability in Hordeum vulgare , one of the most tolerant cereal crops ( Mansour and Stadelmann, 1994 ). Other physiological parameters such as gas-exchange (stomatal closure) and photosynthetic rates are also affected by osmotic stress and have been shown to decrease due to oxidative damage induced by osmotic stress ( Farooq et al, 2014 ; Ihsan et al, 2016 ).…”

“…The susceptible cultivars of wheat were shown to have decreased cytoplasmic viscosity, whereas, tolerant varieties maintained higher viscosity under high salt concentration. Thus, characteristics such as membrane permeability and cytoplasmic viscosity are important in deciding salt tolerance and vary widely among crop species ( Mansour and Stadelmann, 1994 ). The physiological and phenotypic responses that occur in wheat plants is highly dependent on the ability to perceive and induce downstream signaling components.…”

Response of wheat plants to sodium and calcium ion interaction under saline environment

“…Salinity stress changes water permeability of the cell membrane. At high salinity level water permeability of coleoptile subepidermal cells is decreased (Mansour and Stadelmann, 1994). No visual symptoms of wilting may appear though water permeability may significantly be decreased by salinity stress.…”

NaCl-induced changes in plasma membrane lipids and proteins of Zea mays L. cultivars differing in their response to salinity

“…The previous authors proposed that the PM might have a critical role in salt tolerance based on the PM different responses of species/cultivars contrasting in their response to saline conditions. Salt stress induces alterations in the PM permeability, which varying greatly between cultivars differing in salt tolerance (Zongli et al 1987;Mansour et al 1993;Mansour and Stadelmann 1994;Mansour 1995Mansour , 1997. PM permeability measurement probes alterations in PM lipid composition/structure (van Zoelen et al 1978;Stadelmann and Lee-Stadelmann 1989;Russell 1989;Mansour 1997).…”