Stress tolerance in the marsh plant Spartina patens: Impact of NaCl on growth and root plasma membrane lipid composition

Abstract

The C‐4 salt marsh grass, Spartina patens, thrives in the upper portion of the marsh where soil salinities may be equal to coastal seawater. Spartina patens was grown in hydroponic culture in a greenhouse at 0, 340, and 510 mM NaCl, and measured for growth, tissue cation content, and root plasma membrane (PM) lipid composition. From 0 to 340 and 510 mM, the shoot growth decreased, but root growth was not affected. The Na+ content increased in both shoots and roots when plants were grown in salt, while the shoots had a decreased K+ content and the roots had a decreased Ca2+ content. Spartina patens root plasma membrane was isolated with an aqueous polymer two‐phase system. The purity of the plasma membrane was verified with cytochemical tests on membrane enzyme markers. Plasma membrane lipids were stable relative to the membrane protein content. Molar percentages of sterols (including free sterols) and phospholipid decreased with increasing salinity. However, glycolipid showed a statistically significant increase in the total lipid as salinity in the medium was increased from 0 to 510 mM. Even at a salinity of 510 mM, the plasma membrane sterol/phospholipid ratio was unaffected by NaCl. When the plants were grown in NaCl media, the plasma membrane had a decreased phosphatidylcholine (PC) and phosphatidylethanolamine (PE) content, but the PC/PE ratios were not affected. The plasma membrane molar percentage of sitosterol in total free sterol increased when plants were grown in salt media. The predominant membrane fatty acids were C11 and C14, and the major unsaturated one was C14:1. An increase in growth medium salinity resulted in a decreased root plasma membrane fluidity.

Growth of Ornamental Grasses Under Salinity Stress

“…Phragmites australis, a species exhibiting greater sensitivity, at the largest dose produced almost 90% fewer shoots than in the control without salinity, whereas in the resistant species Spartina alterniflora, the number of shoots was only 40% lower. The negative effect of salinity on shoots growth in Spartina patens, was reported by Wu et al (1998), while such a negative effect on plant height in Phragmites australis and Spartina alterniflora by Vasquez et al (2006).…”

“…Also, Farooq and Azam (2006) showed a lower water content in wheat leaves under the influence of salinity (100-250 mM NaCl). A lack of an influence of salinity on changes in dry mass in halophytes was shown by Longstreth and Strain (1977) in Spartina alterniflora and by Wu et al (1998) in Spartina patens. This suggests resistance of these species to substrate salinity due to only a moderate water loss.…”

Salicylic acid ameliorates the adverse effect of salt stress on strawberry

“…High concentrations of Na caused membrane disorganization (Greenway & Munns, 1980). Wu et al (1998) pointed out that molar percentages of strerols and phospholipd decreased with increasing salinity. Electrolyte leakage enables cell membrane injury to be assessed when plants are subjected to salinity stress.…”

Composition of Fatty Acids due to Salinity in the Root of in vitro Culture of Musa acuminata L. Planlets of Barangan Cultivars

“…Salt tolerance is not only related to the cellular homeostasis of Na + ions but also involves the adaptation of secondary metabolite effects on the effects of salinity such as oxidative damages and changes in the level and composition of fatty acids of glycerol lipid in the roots and leaves (Yu et al, 1998;Wu et al, 1998). In addition to fatty acids involved in defense salinity stresses (Aghaleh and Nikman, 2009).…”