Search Results - (Author, Cooperation:M. Tausz)

2014-05-09

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Air/analysis ; Atmosphere/chemistry ; Australia ; Breeding ; Carbon Dioxide/analysis/*pharmacology ; Crops, Agricultural/*chemistry/*drug effects/metabolism ; Diet ; Edible Grain/chemistry/drug effects/metabolism ; Fabaceae/chemistry/drug effects/metabolism ; Global Health/trends ; Humans ; Iron/analysis/deficiency/metabolism ; Japan ; *Nutritional Status ; Nutritive Value/*drug effects ; Photosynthesis/drug effects ; Phytic Acid/analysis/metabolism ; Public Health/*trends ; United States ; Zinc/analysis/deficiency/metabolism

1439-0329

Blackwell Publishing Journal Backfiles 1879-2005

Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition

Biochemical effects of both low and high ozone impact in long-term and short-term experiments are well investigated and documented; however, short-term treatments with moderate ozone levels have revealed divergent information concerning the biochemistry of needle tissues. Damage to the meristems of spruce trees have been found for several ozone treatments, in the form of an enhanced number of chromosomal aberrations, which appeared to be persistent for up to 2 years after the ozone challenge. One of the main aims of the present study was to determine whether a moderate ozone concentration is able to induce damage in needle biochemistry and/or only in the genetic material of root meristems. In the experiment three different clones of Norway spruce trees (Picea abies) were challenged with moderate ozone concentrations (up to 80 nl/l) for 11 weeks in greenhouses. Simultaneous investigations of root tip meristematic cells and the biochemical status of needle tissues regarding antioxidants and pigments were performed at two different sampling times: directly after the ozone treatment and 1 year later. Ozone effects in needles were absent both at the end of the fumigation and also after 1 year, but different clonal behaviour was found. Effect of ozone on chromosomal aberration rates in root tip meristems were observed and also the types of persisting chromosomal aberrations changed within the time course and within the different clones.

Electronic Resource

0931-1890

Key words Norway spruce ; Ozone ; Drought stress ; Gas exchange ; Antioxidants ; Pigments

Springer Online Journal Archives 1860-2000

Biology

Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition

Abstract  To investigate the effects of ozone exposure and soil drought, singly and in combination, on gas exchange, antioxidant contents and pigments in current-year needles of Norway spruce [Picea abies (L.) Karst.] 4-year-old seedlings were fumigated in growth chambers with either charcoal-filtered air or with 100 nl l–1 ozone for 106 days. After 3 weeks a 20% reduction in gas exchange was observed in ozone-treated seedlings. However, no further decrease occurred in spite of continued ozone exposure. Whole needle ascorbate and apoplastic ascorbate increased until the end of the experiment and contents were 62% and 82%, respectively, higher than in ozone-free controls. This increase in ascorbate might have protected net photosynthesis from further decline. Ozone pre-treated plants and ozone-free controls were subjected to soil drought for 38 days which caused stomatal narrowing. Thereby ozone uptake was reduced when compared to well watered seedlings. At the end of the experiment drought alone, and even more in combination with ozone, had also caused an increase in ascorbate. Glutathione increased only in drought-stressed seedlings. The redox states of the ascorbate and the glutathione pools were not affected by any treatment. Superoxide dismutase activity declined under both stresses but was most reduced by ozone alone. While chlorophyll and neoxanthin contents remained unchanged, carotenes were significantly decreased upon drought. The combination of O3 and drought induced increased lutein contents, an increased pool size of the xanthophyll cycle as well as an increased epoxidation status of the xanthophyll cycle. These results suggest that spruce needles seem to be able to acclimate to ozone stress but also to drought stress by increasing their ascorbate pools and protecting pigments.

Electronic Resource

1615-6102

Glutathione ; Root ; Chromosomal aberration ; Ultrastructure ; Picea abies

Springer Online Journal Archives 1860-2000

Biology

Summary Young spruce seedlings (Picea abies [L.] Karst.) grown in hydroponic culture were exposed to three different concentrations (50,100, and 500 μM) of reduced glutathione for 24 h. These physiologically relevant concentrations of glutathione had a multiple effect on the investigated tissue. Feeding of glutathione to roots increased the concentrations of thiols (glutathione, cysteine, and γ-glutamyl-cysteine) in roots, decreased the rate of cell divisions, induced mitotic abnormalities, and affected the cell ultrastructure. Electron micrographs showed effects such as advanced vacuolation, dilated rough-endoplasmic-reticulum cisternae, and separations of the plasma membrane from the cell wall.

Electronic Resource

1573-2932

Pinus ponderosa ; ozone ; ascorbate ; tocopherol ; glutathione ; antioxidants ; oxidative stress

Springer Online Journal Archives 1860-2000

Energy, Environment Protection, Nuclear Power Engineering

Abstract Damage of Pinus ponderosa Dougl. Ex P. and C. Laws, in the San Bernardino Mountains in Southern California is a well-known example for ozone-phytotoxic effects in forests. In October 1997, needles were collected at the severely impacted Dogwood plot, where pines showing severe crown thinning (‘symptomatic’) and asymptomatic ones grow together. Visible chlorosis was not or only mildly developed on the sampled current year's (c) and previous year's (c+l) needles at the time of collection. In sun exposed needles of symptomatic trees, but not in needles which were dark adapted overnight, significantly lower glutathione contents were found compared to asymptomatic trees. In asymptomatic trees sun-exposed and dark adapted needles contained 85 to 90% of the glutathione pool in the reduced state, whereas in sun exposed needles of symptomatic trees a significantly higher proportion of oxidised glutathione was observed (〉20%). The redox state of the ascorbate pool remained unaffected, but needles of asymptomatic trees showed a significant decrease of total ascorbate upon darkening. Tocopherol contents were not significantly different between symptomatic and asymptomatic individuals. The results indicate oxidative alterations in needles of symptomatic trees. Since these changes are detectable before severe visual symptoms appear on the needles, they represent initial physiological damage and might be useful for an early risk assessment of ozone phytotoxic potential on pine trees in the field.

Electronic Resource