Amiloride reduces sodium transport and accumulation in the succulent xerophyte Zygophyllum xanthoxylum under salt conditions.
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.
Wu
Guo-Qiang
GQ
Key Laboratory of Grassland Agro-ecosystem, Ministry of Agriculture, School of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, People's Republic of China.
Wang
Qian
Q
Bao
Ai-Ke
AK
Wang
Suo-Min
SM
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*
D002412:Cations; D012492:Salts; D026941:Sodium Channel Blockers; D000584:Amiloride; D012964:Sodium; D011188:Potassium