Protein synthesis in loblolly pine seedlings during water-deficit /
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| Other Authors: | , , |
| Format: | Thesis Book |
| Language: | English |
| Published: |
1991.
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| Subjects: | |
| Online Access: | Link to OAKTrust copy |
| Abstract: | The effect of water-deficit on gene expression and protein synthesis in seedlings of loblolly pine was investigated. Several systems for inducing and monitoring the reaction of pine seedlings to low water potential were examined. Tissue slices were floated on liquid media, with various concentrations of mannitol added as an osmoticum and [^35]S-methionine to label nascent proteins. Second, labelling of proteins in whole seedlings was attempted by direct application of 35S-methionine to gently abraded cotyledons, followed by transplanting of the seedlings to vermiculite of lower water potential. It was found that neither system was adequate to^ monitor qualitative or quantitative changes in protein sysnthesis. The change in Km of malate dehydrogenase (MDH; L-malate:NAD oxidoreductase; EC 1.1.1.37) over the temperature range from 15° to 40°C was examined in an attempt to extend the Thermal-Kinetic-Window hypothesis from crop species to loblolly pine. If valid, the hypothesis delineates the optimal temperature for normative plant metabolism, hence experimental conditions as well. It was found that there was little response in MDH from pine seedlings to temperature, nor were there significant differences between the populations. This line of inquiry was abondoned, and pine seedlings were subsequently grown in accordance with published data describing natural growth conditions. The limitations of in vivo labelling of proteins to examine changes in protein synthesis, with water-deficit, lead to the use of an in vitro labelling approach. A method was adapted to extract total RNA from 1 gram (fresh weight) quantities of needle tissue, followed by in vitro translation of the total RNA in the presence of 3 5smethionine. Labelled proteins were fractionated by two-dimensional gel electrophoresis and visualized by autofluorography... |
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| Item Description: | Typescript (photocopy). Vita. "Major subject: Plant Physiology." |
| Physical Description: | xiv, 143 leaves : illustrations ; 29 cm |
| Bibliography: | Includes bibliographical references. |