title: Amiloride reduces sodium transport and accumulation in the succulent xerophyte Zygophyllum xanthoxylum under salt conditions.
abstract: To investigate the effects of amiloride, which is an inhibitor of Na(+)/H(+) antiporter (NHX), on Na(+) accumulation and transport at the whole plant level, in this study, 3-week-old Zygophyllum xanthoxylum plants were exposed to 25, 50 and 100 mM NaCl with or without 0.5 mM amiloride. After 72 h of treatment, dry weight, tissue water content, Na(+) and K(+) concentrations, and transcript levels of ZxNHX were determined. The results indicated that, under salt conditions, leaf Na(+) concentration, total Na(+) quantity and root net Na(+) uptake rate in plants treated with amiloride are significantly lower than those in control plants. Amiloride remarkably increased Na(+) proportion in stem and decreased Na(+) proportion in leaf of Z. xanthoxylum. Furthermore, our results showed that the transcript levels of ZxNHX are down-regulated by amiloride. It is clear that the inhibition of vacuolar Na(+)/H(+) antiporter by amiloride could disrupt Na(+) accumulation of leaf, and reduce Na(+) uptake by root and Na(+) transport from stem to leaf, thus resulting in the growth inhibition of Z. xanthoxylum exposed to salt.
authors.affiliation: Key Laboratory of Grassland Agro-ecosystem, Ministry of Agriculture, School of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, People's Republic of China.
authors.forename: Guo-Qiang
authors.initials: GQ
authors.lastname: Wu
authors.forename: Qian
authors.initials: Q
authors.lastname: Wang
authors.forename: Ai-Ke
authors.initials: AK
authors.lastname: Bao
authors.forename: Suo-Min
authors.initials: SM
authors.lastname: Wang
mesh_terms: D000584:Amiloride / Q000494:pharmacology*; D002412:Cations / Q000378:metabolism; D017136:Ion Transport; D011188:Potassium / Q000378:metabolism; D012492:Salts / Q000494:pharmacology*; D012964:Sodium / Q000378:metabolism*; D026941:Sodium Channel Blockers / Q000494:pharmacology*; D032445:Zygophyllum / Q000737:chemistry / Q000187:drug effects* / Q000378:metabolism*
chemical_list: D002412:Cations; D012492:Salts; D026941:Sodium Channel Blockers; D000584:Amiloride; D012964:Sodium; D011188:Potassium