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

Abstract

Two contrasting maize (Zea mays L.) cultivars, i.e., Giza 2 (salt tolerant) and Trihybrid 321 (salt sensitive), were grown hydroponically to study NaCl effect (100 mM) on root plasma membrane (PM) lipid and protein alterations. The PM total sterols of Trihybrid 321 were decreased while that of Giza 2 was increased in response to salt. Salt imposition had no significant effect on PM total glycolipids and proteins of both cultivars. The PM total phospholipids were increased in Trihybrid 321 but it did not change significantly in Giza 2 after salinity stress. Molecular percentage of PM phospholipids and fatty acids of both cultivars was different in absence (0 mM) and presence (100 mM) of salt. The most abundant phospholipids in untreated Trihybrid 321 PM were phosphatidylglycerol (PG), phosphatidylcholine (PC), phosphatidylethanolamine (PE) and phosphatidylserine (PS), which changed into PG, PS, phosphatidylinositol (PI) and PC after salt treatment. However, the dominant phospholipids of the control PM of Giza 2 were PC, PE, PS and PG, which changed into PG, PE, PS and diphosphatidylglycerol (DPG) after salt imposition. Over 60% of the total fatty acids were saturated in control and salinized PM of both cultivars, which was increased after salt stress. The predominant fatty acid in the control and salinized PM of Trihybrid 321 was C18:1 and C17:0, respectively. However, in control and treated PM of Giza 2, the predominant fatty acid was C17:0 and C20:0, respectively. Qualitative and quantitative differences in PM protein patterns were found in both cultivars with and without salt. PM lipid changes enhanced membrane integrity, reflected in different ion accumulation (Mansour et al. 2005), and hence salt tolerance of Giza 2.

Calcium can moderate changes on membrane structure and lipid composition in cowpea plants under salt stress

“…5). Although we have not observed an increase in cowpea salt tolerance with reductions in membrane fluidity, other authors have concluded that this reduction was related to salt tolerance in maize (Salama et al 2007). This discrepancy in results may be explained by the fact that the decrease in membrane fluidity observed in cowpea leaves was insufficient to reduce membrane damage.…”

“…When two maize cultivars contrasting in salt tolerance were grown at 100 mM NaCl, there was a decrease in unsaturated/saturated fatty acid ratio of the PM, but it was higher in salt tolerant cultivar (Salama et al 2007). On the contrary, in broccoli root cells, Lopéz-Pérez et al (2009) observed that salinity increased unsaturated fatty acid content, resulting in less compact and more fluid plasma membrane.…”

“…In addition, Ca 2? plays an essential role in processes that maintain the structural and functional integrity of plant membranes, since it interacts with phospholipids and proteins, stabilizing the membranes (Rengel 1992;Marschner 1995).…”

Regulation by salt of vacuolar H+-ATPase and H+-pyrophosphatase activities and Na+/H+exchange

“…A crosstalk between osmotic stress and vacuole accumulation of Na + has been demonstrated in Arabidopsis where osmotic stress activates the synthesis of abscisic acid (ABA), which upregulates the transcription of AtNHX1. 99 Moreover, other factors may account for the regulation of tonoplast transport proteins, such as changes in lipid-protein interactions, since alterations in membrane lipid composition and structure have been associated with salt stress, 63,64 and ATPase activity could be regulated by changes in the membrane lipids. 65,66 Regulation of Na + /H + Antiport Activity by Salt Vacuolar Na + /H + antiporters have been investigated as the key to salt tolerance in plants.…”

Physicochemical techniques in description of interactions in model and native plant membranes under stressful conditions and in physiological processes

“…The composition of the main lipid fractions in plasmalemma chloroplast and microsomal membranes of various plants in ( 3.4-54.3 1.0-28.0 Allen et al 1964;Galliard 1968;Roughan and Batt 1969;Wintermans 1960;Harwood 1975Harwood , 1980Sheppard et al 1978;Evans et al 1990;Palta et al 1993;Quartacci et al 1995Quartacci et al , 2001Uemura et al 1995;Hernandez and Cooke 1997;Gniazdowska et al 1999;Welti et al 2002;Nouairi et al 2006;Salama et al 2007;Toumi et al 2008;Filek et al 2009;Zamani et al 2010;Cacho et al 2012;Ibrahim et al 2012;Li et al 2014;Sui and Han 2014 Chloroplast 6.7-32.0…”