Journal Article

Effects of drought and canopy ozone exposure on antioxidants in fine roots of mature European beech (<i>Fagus sylvatica</i>)

Kristine Haberer, Karin Herbinger, Maria Alexou, Heinz Rennenberg and Michael Tausz

in Tree Physiology

Volume 28, issue 5, pages 713-719
Published in print May 2008 | ISSN: 0829-318X
Published online May 2008 | e-ISSN: 1758-4469 | DOI: http://dx.doi.org/10.1093/treephys/28.5.713
Effects of drought and canopy ozone exposure on antioxidants in fine roots of mature European beech (Fagus sylvatica)

Show Summary Details

Preview

We quantified ascorbate, glutathione and α-tocopherol in fine roots of mature Fagus sylvatica L. under free-air canopy ozone (O3) exposure (twice ambient O3 concentration, 2×[O3]) during two growing seasons that differed in the extent of summer drought (exceptional drought year 2003, average year 2004). This design allowed us to test whether O3 exposure or drought, or both, affected root antioxidants during the growing season. In both years, root ascorbate and α-tocopherol showed a similar relationship with volumetric soil water content (SWC): ascorbate concentrations on a root dry mass basis increased from about 6 to 12 μmol g−1 when SWC dropped from 25 to 20%, and a-tocopherol increased from 100 to 150 nmol g−1 at SWC values below 20%. Root glutathione showed no relationship with SWC or differences between the dry and the average year, but it was significantly and consistently diminished by 2×[O3]. Our results were inconclusive as to whether shoot–root translocation of glutathione or glutathione production in the roots was diminished. Phloem glutathione concentrations in the canopy remained constant, but reduced transport velocity in the phloem and, as a consequence, reduced mass flow of glutathione cannot be ruled out.

Keywords: ascorbate; glutathione; mycorrhiza; oxidative stress; α-tocopherol

Journal Article.  0 words. 

Subjects: Plant Sciences and Forestry

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.