Redox state and peroxidase system in sunflower plants exposed to ozone

Citation
A. Ranieri et al., Redox state and peroxidase system in sunflower plants exposed to ozone, PLANT SCI, 159(1), 2000, pp. 159-167
Citations number
51
Categorie Soggetti
Plant Sciences","Animal & Plant Sciences
Journal title
PLANT SCIENCE
ISSN journal
01689452 → ACNP
Volume
159
Issue
1
Year of publication
2000
Pages
159 - 167
Database
ISI
SICI code
0168-9452(20001008)159:1<159:RSAPSI>2.0.ZU;2-W
Abstract
Sunflower plants subjected to a short-term fumigation with O-3 (150 ppb for 4 h repeated for 4 days) exhibited an increase in total ascorbate content, accompanied by a marked oxidation of ascorbate, leading to a decrease in i ts redox state, either at intracellular or extracellular level. O-3 exposur e induced a rise in free extracellular peroxidase (POD) activity, assayed b y syringaldazine as electron donor, as well as in the ionically and covalen tly cell wall bound PODs. On the contrary, the activity of both extracellul ar and intracellular guaiacol-POD did not show significant changes as a con sequence of the pollutant exposure. The stimulation of syringaldazine-POD a ctivities may be related to the effect of ozone on the growth of the cells, inducing an early senescence through the activation or acceleration of lig nification processes. Beside: the reduced plasticity of the cell wall may o ppose an unspecific mechanical resistance against the abiotic stress induce d by the ozone exposure. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.