Responses of the xanthophyll cycle pool and ascorbate-glutathione cycle toozone stress in two tobacco cultivars

Citation
S. Pasqualini et al., Responses of the xanthophyll cycle pool and ascorbate-glutathione cycle toozone stress in two tobacco cultivars, FREE RAD RE, 31, 1999, pp. S67-S73
Citations number
25
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Biochemistry & Biophysics
Journal title
FREE RADICAL RESEARCH
ISSN journal
1071-5762 → ACNP
Volume
31
Year of publication
1999
Supplement
S
Pages
S67 - S73
Database
ISI
SICI code
1071-5762(1999)31:<S67:ROTXCP>2.0.ZU;2-P
Abstract
Plants of Nicotiana tabacum (O-3-tolerant cv Bel-B and O-3-sensitive cv Bel -W3) were exposed to 150 ppb of ozone for 5 h; the fumigation produced visu al injury in mature leaves, particularly in Bel-W3. After O-3-treatment the pigments of the xanthophyll cycle pool decreased in both cvs, with a stron g reduction in violaxanthin content, while antheraxanthin and zeaxanthin in creased slightly. Under these conditions the content of leaf abscisic acid (ABA) markedly increased, particularly in Os-sensitive cv, indicating that the violaxanthin may have been partially converted into ABA. The control pl ants of Bel-B showed an ascorbic acid content four times greater than Bel-W 3 and the ozone treatment did not produce significant differences in the as corbic acid content and in the redox state. The two tobacco cvs were found to have similar total glutathione content, however the redox state was lowe r in O-3-sensitive cv and decreased after ozone exposure. Ozone fumigation caused an increase in oxidized glutathione, particularly in Bel-W3, associa ted with a reduced glutathione reductase (GR) activity and a reduced GR pro tein content.