Author
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Triplett, Barbara |
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Johnson, Damicca |
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Submitted to: In Vitro Cellular And Developmental Biology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 1/29/1999 Publication Date: N/A Citation: N/A Interpretive Summary: When floated on a defined culture medium in a culture dish, young cotton seeds will produce fiber within a three week period. Our laboratory is interested in examining the effects of altered states of gravity on fiber development to determine how the plant regulates the production of the cell wall, i.e., the part of cotton fiber used for textile applications. Before conducting experiments under altered gravity conditions, modifications to the liquid culture medium need to be made. In this study we have systematically examined the effects of four gelling agents at several concentrations on fiber production in culture. A rapid screening method based on staining with a dye indicated that fiber growth on medium containing one gelling agent was similar to fiber growth on liquid medium. More detailed analysis of fiber development revealed that fiber length was not influenced by the addition of the gelling agent, however, cellulose accumulation was reduced by nearly 50% compared with fibers produced in liquid media. Tissue fresh and dry weight was also reduced by nearly one half on solid media. This difference in growth response on gelled media could be due to differences in water availability, to nutrients becoming trapped in the gel, or to toxicity of contaminants co-purifying with the gelling agent. Embryo development in the seed was also affected by the presence of a gelling agent in the culture medium. By identifying why ovule growth and fiber cellulose biosynthesis are reduced in cultures grown on gelled media, it will be possible to reveal new information about these processes in a system that is less complicated than physiological studies at the whole plant level. Technical Abstract: When floated on a defined medium, young cotton (Gossypium hirsutum) ovules will produce fiber in vitro within a three week period. Our laboratory is interested in examining the effects of hypergravity and microgravity on fiber development to determine how the plant regulates the orientation of cellulose microfibrils in the fiber wall. Before conducting experiments under altered gravity conditions, modifications to the liquid culture medium need to be made. In this study we have systematically examined the effects of four gelling agents at several concentrations on fiber production in culture. A rapid screening method using Toluidine Blue O staining indicated that fiber growth on liquid medium. More detailed analysis of fiber development revealed that fiber length was not influenced by the addition of Phytagel, however, cellulose accumulation was reduced by nearly 50% compared with fibers produced in liquid media. Ovule fresh and dry weight was also reduced by nearly one half on solid media. This difference in growth response on gelled media could be due to differences in media matric potential, to the immobility of ions trapped within the gel, or to toxicity of contaminants co-purifying with Phytagel. Embryo development in ovulo was also affected by the presence of a gelling agent in the culture medium. By identifying why ovule growth and fiber cellulose biosynthesis are reduced in cultures grown on gelled media, it will be possible to reveal new information about these processes in a system that is less complicated than physiological studies at the whole plant level. |
