Rhythms of ethylene production and stomatal conductance of cotton /
Light strongly impacts plant processes and is instrumental in establishing rhythms in photosynthetic responses, plant hormone activity, and enzymatic activity. Ethylene, the plant hormone that causes fruit ripening, may also be influenced by light. Cotton (Gossypium hirsutum) cultivar 'DPLSO�...
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
1998.
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| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=732838351&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | Light strongly impacts plant processes and is instrumental in establishing rhythms in photosynthetic responses, plant hormone activity, and enzymatic activity. Ethylene, the plant hormone that causes fruit ripening, may also be influenced by light. Cotton (Gossypium hirsutum) cultivar 'DPLSO' was exposed to the following light and/or dark treatments over a 72-h period'. a 12-h photoperiod, continuous light, or continuous dark condition. Ethylene evolution, l-aminocyclopropane-l-carboxcylic acid (ACC), N-malonyl-l-aminocyclopropane-l-carboxylic acid (MACC), ACC synthase, and ACC oxidate were assayed. Comparisons were made between leaf disc and whole-plant sampling. In addition, stomatal conductance was measured under the three light conditions to determine its effect on ethylene evolution. Different patterns of ethylene evolution were observed between the leaf-disc and whole-plant sampling methods. The whole-plant method during a 72-h study while the leaf disc method did not. The leaf disc method detected significantly more ethylene than did the whole-plant method in all treatments. The greater ethylene production was attributed to the higher concentration of CO2 in the glass tubes compared to the Magenta vessels. A rhythmic nature was observed for ACC and MACC in all treatments; however, rhythms of MACC were disrupted after hour 36 in the continuous dark treatment. Rhythms of MACC were more synchronized with the rhythms of ethylene production than were the rhythms of ACC. A rhythm was observed for ACC synthase activity. In addition, rhythms of ACC synthase were synchronized with those of ACC. The activity of ACC oxidise did not show a circadian rhythm, but peaks of activity were observed throughout the 12-h photoperiod and continuous light conditions. However, peaks were non-existent in the continuous dark condition. Rhythms were observed for abaxial and abaxial stomatal conductance in the 12-h photoperiod and light condition, but not in the continuous dark continuous condition. Stomatal conductance and ethylene production were synchronized for the 12-h photoperiod and continuous light condition. |
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| Item Description: | Vita. |
| Physical Description: | xiv, 137 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilm Inc. |
| Bibliography: | Includes bibliographical references: pages 127-136. |