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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2011-1-25
pubmed:abstractText
Leaf senescence induced by 2,4-dichlorophenoxyacetic acid (2,4-D) and senescence inhibition caused by supplementation with silver (Ag(+)) ions in the form of silver nitrate (AgNO(3)) or silver nanoparticles (AgNPs) were investigated in 8-day-old mung bean (Vigna radiata L. Wilczek) seedlings. Inhibition of root and shoot elongation were observed in mung bean seedlings treated with 500?M 2,4-D. Concomitantly, the activity of 1-aminocyclopropane-1-carboxylic acid synthase was significantly induced in leaf tissue. Leaf senescence induced by 2,4-D was closely associated with lipid peroxidation as well as increased levels of cytotoxic hydrogen peroxide (H(2)O(2)) and superoxide radicals (O(2)(·-)). Despite decreased catalase activity, the activities of peroxidase, superoxide dismutase, monodehydroascorbate reductase, dehydroascorbate reductase, and glutathione reductase were increased during 2,4-D-induced leaf senescence. Further, the levels of reduced ascorbate, oxidized ascorbate, and reduced glutathione were markedly decreased, whereas the level of oxidized glutathione increased. 2,4-D-induced leaf senescence in mung bean was accompanied by an increase in positive terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling, nuclear DNA fragmentation, and the activity of a 15-kDa Ca(2+)-dependent DNase. Supplementation with 100?M AgNO(3) or AgNPs inhibited 2,4-D-induced leaf senescence. The present results suggest that increased oxidative stress (O(2)(·-) and H(2)O(2)) led to senescence in mung bean leaves. Furthermore, significantly induced antioxidative enzymes are not sufficient to protect mung bean cells from 2,4-D-induced harmful ROS.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
1873-2690
pubmed:author
pubmed:copyrightInfo
Copyright © 2010 Elsevier Masson SAS. All rights reserved.
pubmed:issnType
Electronic
pubmed:volume
49
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
168-77
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
2,4-dichlorophenoxyacetic acid-induced leaf senescence in mung bean (Vigna radiata L. Wilczek) and senescence inhibition by co-treatment with silver nanoparticles.
pubmed:affiliation
Department of Plant Sciences, Centre for Excellence in Genomic Sciences, School of Biological Sciences, Madurai Kamaraj University, Madurai 625021, India.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't