Author
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Smith, David |
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Gross, Kenneth |
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Submitted to: BARC Poster Day
Publication Type: Proceedings Publication Acceptance Date: 3/1/1997 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: Fruit firmness is important in marketing and edibility of fruits and vegetables. Although the mechanisms involved in fruit softening are not fully understood, solubilization of cell wallcomponents is undoubtedly important. The importance of several cell wallhydrolases (e.g., polygalacturonase and pectin methylesterase) in softening have been tested. However, only small differences in softening have been observed. Therefore, it is necessary to examine the role of other hydrolases. We are determining the role of beta-galactosidase genes during tomato fruit ripening and their importance in the softening and/or ripening process. Our plan is to identify the beta-galactosidase genes expressed in ripening fruit, characterize them at the molecular level and to knock out their expression in transgenic plants by antisense and/or cosuppression methodologies. We have identified, by degenerate PCR and low stringency screening, seven beta-galactoside genes expressed during fruit ripening of 'Rutgers' tomato. Full-length cDNAs for three of the genes were isolated and sequenced. Nearly full-length cDNAs were isolated for three of the genes, and RT-PCR will be done to complete the sequencing. No cDNA was isolated for one of the genes identified by R-PCR. Southern analysis was done for all of the genes, and each appears to be a single copy gene. Cross hybridization among the seven genes does not occur (at high stringency), or can be prevented by probe choice. Each gene is expressed in fruit tissues. Detailed Northern analysis is currently underway. In situ analysis has not begun. Sense and antisense constructs for each gene are being made in binary vectors to create transgenic plants. |