Effects of calcium application on the salt tolerance and sodium excretion from salt glands in zoysiagrass (Zoysia japonica)

Abstract

Zoysiagrass (Zoysia japonica Steud.), a native grass in Japan, is a warm‐season turfgrass displaying high salt tolerance, mainly derived from salt excretion through salt glands. The present study focused on how external calcium (Ca) affects sodium (Na) excretion from salt glands to relieve salt stress, including response to oxidative stress, and discussed the physiological mechanisms possibly involved. Treatments using 0, 25, 50, 75, 100, 125 and 150 mmol/L sodium chloride (NaCl), with or without applying 2 or 10 mmol/L calcium chloride (CaCl2), were conducted for seven days. Growth inhibition and an abrupt increase in Na excretion from salt glands occurred above 100 mmol/L NaCl treatment, while Na concentrations in shoot and root tissues increased with increasing NaCl concentration from 0 to 75 mmol/L treatment. Above 100 mmol/L NaCl treatment, pectic acid‐binding Ca and glycinebetaine concentrations decreased in shoot and root tissues, but free proline concentration and the activities of plasmalemma ATPase, catalase (CAT) and ascorbate peroxidase (APX) increased. Calcium application alleviated growth inhibition when added to high level of NaCl treatments (over 100 mmol/L NaCl). Compared to the treatment without Ca, Na concentration in shoot and root tissues and ATPase activity in the root decreased, but Na exclusion from salt glands, pectic acid‐binding Ca concentration in shoot and root tissues, and ATPase, CAT and APX activities in the shoot increased. Thus, Na excretion through salt glands seems to occur when Na concentration in the plant exceeds its accumulation limit, and this salt tolerance reaction involving salt glands proceeds in two steps: the grass absorbs and accumulates Na in the shoot and root up to a threshold, above which Na is removed through salt glands. Calcium application promoted Na excretion through salt glands, especially under growth‐inhibiting Na concentrations, which might be induced by the increase in extracellular excretion of Na by plasmalemma ATPase.

Effect of Sulfur and Clean Salt on Antioxidant Enzymes and Proline Content in Improving Salt Tolerance of Two Lettuce Cultivars Grown in Basrah

“…The result indicated that there were increment in CAT, POD enzymes activity and proline content, in each two cultivars in the control treatment and this agreed with Zhang et al (2013), Hela et al (2011 and Younis et al (2008) that high salt led to increase in CAT and Zhang et al (2013), Hela et al (2011 and Younis et al (2008) that high salt led to increase in CAT and POD enzymes and proline supplement of sulfur led to increase the metabolism of Thiobacillus thioparus bacteria and led to the pH lower and increasing the availability of macro and micro nutrients which lead to increase the solutes which adjusting the water potential and finally regulate the cellular water and absorption of water by plant (Abdelhamid et al, 2013;Kadhim, 2016;Riffat & Ahmad, 2018) and finally reduce CAT, POD and proline. Addition of calicium act on increasing the synthesize of carbohydrates and various solutes that lead to adjusting cellular potential (Tian et al, 2015) and this agreed with Maeda (2019) that the use of calcium act to promote growth and decrease proline and CAT, POD enzymes.This result indicate that sulfur and clean salt ameliorates the adverse effects of salinity on lettuce plants that grow on sodic soil.…”

Increasing Ca2+ accumulation in salt glands under salt stress increases stronger selective secretion of Na+ in Plumbago auriculata tetraploids

“…It was shown that Ca 2+ promotes the secretion of Na + from salt glands of recretohalophytes ( Ding et al., 2010 ; Maeda, 2019 ). In our previous study on whole-leaf secretion rates in P. auriculata under salt stress, Ca 2+ content in diploid leaves was higher than that in tetraploid leaves, but the Na + secretion rate was lower in diploids than in tetraploids ( Duan et al., 2023 ).…”

Variations in ion transportation and accumulation in alfalfa plants under NaCl and Na2HCO3 stresses with different pH levels

“…Mg 2+ is a key component of plant chlorophyll and has antiaging function (Khan et al., 1999). The high concentration of Na + has high activity of replacing Ca 2+ from the plasma membrane, and the balance of Ca 2+ in the cell is affected (Maeda, 2019). The imbalance of intracellular Ca 2+ is the primary response to salt stress, which leads to many secondary salt damage reactions (Storey, 1995).…”