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dc.creatorPosey, Karen Lasheaen_US
dc.descriptionDue to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to, referencing the URI of the item.en_US
dc.descriptionIncludes bibliographical references.en_US
dc.descriptionIssued also on microfiche from Lange Micrographics.en_US
dc.description.abstractOzone, a phytotoxic air pollutant, is formed from photochemical reactions of hydrocarbons and nitrogen oxides in the troposphere. Ozone is taken into the plant through the stomata, and quickly broken down into hydroxyl radicals. These hydroxyl radicals can oxidize portions of the cell and cause damage or may be neutralized by antioxidants. Ozone is known to have a variety of negative effects on plants, including reductions in growth, changes in membrane permeability, and increases in dark respiration. Ozone can also affect photosynthetic parameters, including decreasing photosynthesis, decreasing chlorophyll concentration, and decreasing Rubisco (ribulose1,5-bisphosphate carboxylase/oxygenase) concentration and activity. Damage from ozone might be decreased if the natural antioxidant systems of the plant could enhanced, Ozone and two antioxidants, ethylenediurea and Ozoban, were studied in loblolly pine seedlings to determine their impact on total soluble protein, Rubisco activity, and Rubisco concentration. The objective of this study was to determine how ozone and these antioxidants affect the photosynthetic enzyme, Rubisco, in loblolly pine. Seedlings were exposed to ozone ranging from charcoal-filtered air to 2.5X the ambient ozone concentration in open-top chambers at the study site. Antioxidants were applied every two weeks at the rate of 0 ppm, 150 ppm, and 300 ppm for ethylenediurea; and 0 ppm, 1030 ppm, and 2060 ppm for Ozoban. Total soluble protein was positively affected by the highest concentration of ethylenediurea and all Ozoban concentrations after the ozone peak in May. All significant negative trends in Rubisco activity due to treatments occurred in June, after the ozone peak. Treatment with 300 ppm ethylenediurea or 1030 ppm Ozoban resulted in a decrease in Rubisco activity. Late in the study, after five months of exposure, treatment with 2060 ppm Ozoban or 150 ppm ethylenediurea resulted in increased Rubisco concentrations.en_US
dc.publisherTexas A&M Universityen_US
dc.rightsThis thesis was part of a retrospective digitization project authorized by the Texas A&M University Libraries in 2008. Copyright remains vested with the author(s). It is the user's responsibility to secure permission from the copyright holder(s) for re-use of the work beyond the provision of Fair Use.en_US
dc.subjectplant physiology.en_US
dc.subjectMajor plant physiology.en_US
dc.titleA study of the effect of ozone and antioxidants on ozone-sensitive loblolly pineen_US
dc.typeThesisen_US physiologyen_US
dc.format.digitalOriginreformatted digitalen_US

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