title: Ethylene and nitric oxide are involved in maintaining ion homeostasis in Arabidopsis callus under salt stress.
abstract: In the present study, the role of ethylene in nitric oxide (NO)-mediated protection by modulating ion homeostasis in Arabidopsis callus under salt stress was investigated. Results showed that the ethylene-insensitive mutant etr1-3 was more sensitive to salt stress than the wild type (WT). Under 100 mM NaCl, etr1-3 callus displayed a greater electrolyte leakage and Na(+)/K(+) ratio but a lower plasma membrane (PM) H(+)-ATPase activity compared to WT callus. Application of exogenous 1-aminocyclopropane-1-carboxylic acid (ACC, an ethylene precursor) or sodium nitroprusside (SNP, a NO donor) alleviated NaCl-induced injury by maintaining a lower Na(+)/K(+) ratio and an increased PM H(+)-ATPase activity in WT callus but not in etr1-3 callus. The SNP actions in NaCl stress were attenuated by a specific NO scavenger or an ethylene biosynthesis inhibitor in WT callus. Under 100 mM NaCl, the NO accumulation and ethylene emission appeared at early time, and NO production greatly stimulated ethylene emission in WT callus. In addition, ethylene induced the expression of PM H(+)-ATPase genes under salt stress. The recovery experiment showed that NaCl-induced injury was reversible, as signaled by the similar recovery of Na(+)/K(+) ratio and PM H(+)-ATPase activity in WT callus. Taken together, the results indicate that ethylene and NO cooperate in stimulating PM H(+)-ATPase activity to modulate ion homeostasis for salt tolerance, and ethylene may be a part of the downstream signal molecular in NO action.
authors.affiliation: Key Laboratory of Arid and Grassland Agroecology (Ministry of Education), School of Life Sciences, Lanzhou University, 730000, Lanzhou, People's Republic of China.
authors.forename: Huahua
authors.initials: H
authors.lastname: Wang
authors.forename: Xiaolei
authors.initials: X
authors.lastname: Liang
authors.forename: Qi
authors.initials: Q
authors.lastname: Wan
authors.forename: Xiaomin
authors.initials: X
authors.lastname: Wang
authors.forename: Yurong
authors.initials: Y
authors.lastname: Bi
mesh_terms: D000598:Amino Acids, Cyclic / Q000494:pharmacology; D017360:Arabidopsis / Q000187:drug effects / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics; D005030:Ethylenes / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant / Q000187:drug effects / Q000235:genetics; D006706:Homeostasis / Q000187:drug effects; D009569:Nitric Oxide / Q000378:metabolism*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D009599:Nitroprusside / Q000494:pharmacology; D030821:Plants, Genetically Modified / Q000235:genetics; D011188:Potassium / Q000378:metabolism*; D006180:Proton-Translocating ATPases / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000235:genetics; D012964:Sodium / Q000378:metabolism*; D012965:Sodium Chloride / Q000494:pharmacology*; D013312:Stress, Physiological
chemical_list: D000598:Amino Acids, Cyclic; D029681:Arabidopsis Proteins; C494590:ETR1 protein, Arabidopsis; D005030:Ethylenes; D020030:Nitric Oxide Donors; D011956:Receptors, Cell Surface; D009599:Nitroprusside; D009569:Nitric Oxide; C023863:1-aminocyclopropane-1-carboxylic acid; D012965:Sodium Chloride; C036216:ethylene; D012964:Sodium; D006180:Proton-Translocating ATPases; D011188:Potassium