Amiloride inhibition of vacuolar Na+/H+ antiporter enhance salt stress in Zea mays L. seedlings.
The aim of this study to show the importance of salt intracellular compartmentation as a tolerance mechanism by inhibition of Na+/H+ antiporter system. In this research 4 day/old Zea mays L. seedlings (var. single cross 704) were exposed to 200 and 300 mM NaCl with and without 100 and 200 micromolar amiloride. After 48 h, the roots and shoots of seedlings were harvested separately. The changes of total Na+ absorption, the amount of malondialdehyde and the activity of antioxidant enzymes such as guaiacol peroxidase, ascorbate peroxidase and catalase were analysed. The results indicated that Na+ absorption has been increased by salt stress but was not influenced by amiloride. Malondialdehyde content and the activity of antioxidant enzymes such as guaiacol peroxidase, ascorbate peroxidase and catalase were increased in salt stressed plants specially in plants treated with salt and amiloride. Therefore salt stress has caused osmotic and oxidative stress in plants and amiloride as inhibitor of vacuolar Na+/H+ antiporter has been increased salt stress. Therefore we concluded that Na+ compartmentation in the cell is very important to reduce its damage in the cytosol and vacuolar Na+/H+ antiporter has an essential role in Na+ homeostasis in the cell by exporting excess Na+ to the vacuole.
Tajdoost
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Department of Biology, Urmia University, Urmia, Iran.
Farboodnia
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Heidary
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D000584:Amiloride / Q000494:pharmacology*; D000975:Antioxidants / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects; D010940:Plant Proteins / Q000037:antagonists & inhibitors; D036226:Seedlings / Q000187:drug effects / Q000378:metabolism; D026941:Sodium Channel Blockers / Q000494:pharmacology; D012965:Sodium Chloride / Q000633:toxicity; D017923:Sodium-Hydrogen Exchangers / Q000037:antagonists & inhibitors*; D013312:Stress, Physiological / Q000187:drug effects; D003313:Zea mays / Q000187:drug effects* / Q000378:metabolism*
D000975:Antioxidants; D010940:Plant Proteins; D026941:Sodium Channel Blockers; D017923:Sodium-Hydrogen Exchangers; D012965:Sodium Chloride; D000584:Amiloride