Effects of halone 1301 on Lepidium sativum, Petunia hybrida and Phaseolus vulgaris

Halone 1301 belongs to a group of widely used fire repellants. Although ban ned in several countries, the production has still not been discontinued, a nd thus hazards due to use or spill can be expected. The study reports on e ffects of the halone 1301 on three plant species frequently used for bioind ication studies: Lepidium sativum (mouse-ear cress), Phaseolus vulgaris (bu sh bean) and Petunia hybrida. Plants were exposed to 1 ppbv of the gas in a mbient air under controlled conditions for 18 days (L. sativum), and 45 day s (P. vulgaris, P. hybrida), respectively. None of the plants showed visibl e stress symptoms. Chlorophylls in cress and petunia were unaffected wherea s in beans significant changes of the photosynthetic pigments were observed . Photosynthesis and gas exchange of bean plants were monitored during the experiment, and a lowering of transpiration was noticed. In all investigate d plants, protein contents declined significantly, but despite this reducti on, activity of the glutathione S-transferases (GST) increased strongly in bean and petunia. The significance of this reaction as detoxification step is discussed. (C) 2000 Elsevier Science Ltd. All rights reserved.