title: Function of nitric oxide and superoxide anion in the adventitious root development and antioxidant defence in Panax ginseng.
abstract: The involvement of NO in O(2)(.-) generation, rootlet development and antioxidant defence were investigated in the adventitious root cultures of mountain ginseng. Treatments of NO producers (SNP, sodium nitroprusside; SNAP, S-nitroso-N-acetylpenicillamine; and sodium nitrite with ascorbic acid), and NO scavenger (PTIO, 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl3-oxide) revealed that NO is involved in the induction of new rootlets. Severe decline in number of new rootlets compared to the control under PTIO treatment indicates that NO acts downstream of auxin action in the process. NO producers (SNP, SNAP and sodium nitrite with ascorbic acid) activated NADPH oxidase activity, resulting in greater O(2)(.-) generation and higher number of new rootlets in the adventitious root explants. Moreover, treatment of diphenyliodonium chloride, a NADPH oxidase inhibitor, individually or along with SNP, inhibited root growth, NADPH oxidase activity and O(2)(.-) anion generation. NO supply also enhanced the activities of antioxidant enzymes that are likely to be responsible for reducing H(2)O(2)levels and lipid peroxidation as well as modulation of ascorbate and non-protein thiol concentrations in the adventitious roots. Our results suggest that NO-induced generation of O(2) (.-) by activating NADPH oxidase activity is related to adventitious root formation in mountain ginseng.
authors.affiliation: Research Center for the Development of Advanced Horticultural Technology, Chungbuk National University, Cheongju, Republic of Korea. rktewari_bot@yahoo.com
authors.forename: Rajesh Kumar
authors.initials: RK
authors.lastname: Tewari
authors.forename: Eun-Joo
authors.initials: EJ
authors.lastname: Hahn
authors.forename: Kee-Yoeup
authors.initials: KY
authors.lastname: Paek
mesh_terms: D000975:Antioxidants / Q000494:pharmacology; D001205:Ascorbic Acid / Q000494:pharmacology; D003497:Cyclic N-Oxides / Q000494:pharmacology; D006861:Hydrogen Peroxide / Q000378:metabolism; D007093:Imidazoles / Q000494:pharmacology; D015227:Lipid Peroxidation / Q000187:drug effects; D019255:NADPH Oxidases / Q000037:antagonists & inhibitors / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D005894:Panax / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism*; D010396:Penicillamine / Q000031:analogs & derivatives / Q000494:pharmacology; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D026423:S-Nitroso-N-Acetylpenicillamine / Q000494:pharmacology; D013482:Superoxide Dismutase / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism*
chemical_list: D000975:Antioxidants; D003497:Cyclic N-Oxides; D007093:Imidazoles; D020030:Nitric Oxide Donors; D017382:Reactive Oxygen Species; C110881:S-nitro-N-acetylpenicillamine; D013481:Superoxides; C079391:2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide; D009569:Nitric Oxide; D026423:S-Nitroso-N-Acetylpenicillamine; D006861:Hydrogen Peroxide; D013482:Superoxide Dismutase; D019255:NADPH Oxidases; D010396:Penicillamine; D001205:Ascorbic Acid