Ability of salt glands in Rhodes grass (Chloris gayanaKunth) to secrete Na⁺and K⁺

Abstract

Some plants are able to tolerate salinity using salt glands on the leaf surface, which secrete excess salts transported into the leaves. Rhodes grass (Chloris gayana Kunth) reportedly possesses such salt glands, but the features of secretion remain unclear. In the present study, we compared the ability of Rhodes grass salt glands to secrete sodium and potassium with the aim of clarifying the preference of cations for secretion. In both whole plant experiments and detached leaf experiments, NaCl treatment increased Na + secretion and KCl treatment increased K + secretion. When the ratios of the amount of secreted ions to their concentration in the leaves were compared between Na + and K + , the ratio was greater with Na + than K + .

Ability of multicellular salt glands in Tamarix species to secrete Na+ and K+ selectively

“…As shown in Figures 3 and 6, the proportions of Na + and K + accumulated in plant tissues of T. ramosissima were 3.67 and 11.04, respectively, and those of T. laxa were 3.06 and 8.43, respectively (Figures 3 and 6); this indicates that the Tamarix species had a higher affinity to K + , which led to decreased K + secretion. Similar results have been reported in previous studies on Sporobolus spicatus and Rhodes grass [6,10].…”

“…After detection, it was found that the total ATPase level in the plasma of the secreting cells was four-fold that of the mesophyll cells, and the activity of the former was more sensitive to the mitochondrial inhibitor Na-azide and plasma membrane inhibitor Vanadate; therefore, it was further deduced that H + -ATPase played an important role in the ion secretion. Kobayashi [10] found that the bicellular salt glands of Rhodes grass showed higher ability to secrete Na + than K + , and that the plasma membrane H + -ATPase inhibitors, ion channel inhibitors, Na + -K + -ATPase inhibitors, and Ca 2+ and K + channel inhibitors had different effects on Na + and K ＋ secretion; these findings indicated that the preferential Na + secretion in salt glands might be due to the different secretory channels for different ions. The results of recent research showed that ion secretion of multicellular salt glands was regulated by several salt gland inhibitors, such as proton pump inhibitors, Ca + pump inhibitors and K + channel inhibitors [9][10][11][12][13].…”

“…Kobayashi [10] found that the bicellular salt glands of Rhodes grass showed higher ability to secrete Na + than K + , and that the plasma membrane H + -ATPase inhibitors, ion channel inhibitors, Na + -K + -ATPase inhibitors, and Ca 2+ and K + channel inhibitors had different effects on Na + and K ＋ secretion; these findings indicated that the preferential Na + secretion in salt glands might be due to the different secretory channels for different ions. The results of recent research showed that ion secretion of multicellular salt glands was regulated by several salt gland inhibitors, such as proton pump inhibitors, Ca + pump inhibitors and K + channel inhibitors [9][10][11][12][13]. However, yet to be elucidated is whether multicellular salt glands, of which the subcellular structure is more complicated than that of bicellular salt glands, demonstrate a secretion preference for certain ions; if this is the case, the mechanism behind this process is also unknown.…”

“…The flow of ions between the eight subcells of the salt gland was considered to be driven by hydrostatic pressure [15]. However, with the discovery of ion channels and the use of a variety of inhibitors in recent years, whether the ion secretion is due to active transport has once again become a focus for research on salt secretion mechanisms [9,10]. In early research into the salt secretion characteristics of the salt glands of Tamarix growing in fields and cultured artificially in phytotrons, it was discovered that Na + was the chief ion secreted [7,[16][17][18].…”

6-Benzylaminopurine treatment induces increased pubescence on wheat leaves

“…Norin 61) was cultivated in accordance with our previous report (Kobayashi et al 2007) with modifications. Plants were cultivated in a growth chamber with an air temperature of 25/20°C (12-h day/12-h night cycle).…”