Systemic ozone effects on root hydraulic properties in pima cotton
- Univ. of California, Riverside, CA (United States)
Ambient ozone concentrations have become problematic even in rural, agricultural areas such as the San Joaquin Valley of California. Pima cotton (cv. S6) has been shown to be relatively sensitive to ozone air pollution, at levels occurring in this production area. In this semi-arid area acquisition of water and nutrients may limit yield and biological productivity. Therefore maximal proliferation, exploration, and efficiency of root systems is desirable. Hydraulic conductance provides a parameter to characterize the efficiency of roots and shoots and their interaction. The authors have used a variety of transpiration and pressure vessel techniques to document ozone-induced reduction of root hydraulic conductance in cotton. They hypothesized that these effects are caused by reduced carbohydrate supply due to reduction of photosynthetic capacity of the shoot associated with direct oxidant damage to foliage. However, the authors simulated this reduced photosynthetic capacity by continuously removing leaf area to match that of ozone treated plants. This resulted in a reduction of whole plant biomass similar to ozone-treated plants, but a root/shoot biomass ratio and root hydraulic properties similar to control plants and contrasting with ozone-treated plants. Thus leaf removal did not simulate effects of ozone on root hydraulic properties. A systematic effect of ozone on whole plant function is indicated, perhaps mediated by direct effects on carbohydrate translocation throughout the plant.
- OSTI ID:
- 442881
- Report Number(s):
- CONF-961149-; TRN: IM9712%%306
- Resource Relation:
- Conference: 17. annual meeting of the Society of Environmental Toxicology and Chemistry: partnerships for the environment - science, education, and policy, Washington, DC (United States), 17-21 Nov 1996; Other Information: PBD: 1995; Related Information: Is Part Of SETAC 17. annual meeting -- Abstract book. Partnerships for the environment: Science, education, and policy; PB: 378 p.
- Country of Publication:
- United States
- Language:
- English
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