Objective
Texture is one of the major quality parameters associated with both consumer selection of fruit and for quality in fruit processing. Softening is a major contributor to fruit loss during transportation, storage and marketing. Texture of fruit is determined by some factors such as cell turgor, starch content, but specially by the nature of cell walls. Pectin components of the wall appear to undergo the most important modifications and these are particularly important for determining the quality of processed products such as puree and ketchup. Although changes in other wall polymers such as hemicellulose may also be significant. The structural and chemical changes of the pectin can be correlated with cell wall hydrolases in the fruit. It has been suggested that polygalacturonase (PG) and pectinmethylesterase ( PME) were the main enzymes responsible for pectin degradation and hence softening in fruit. Indeed the down regulation of these enzymes in tomato fruit does result in improved handling and processing characteristics. However7 PG action alone and even PG and PME in combination cannot account for the softening of fruit, since transgenic tomato fruit with reduced levels of these enzymes still fail to significantly prevent softening. Similarly some commercially important fruit such as strawberry do not appear to express any PG activity. Thus other enzymes within the fruit may be having a major effect on softening. Other candidate enzymes could include pectate Iyase (PEL) or cellulase. The action of PEL is similar to that of PG and cellulase maybe involved in modification of other cell wall polymers such as hemicellulose.
Preliminary work has identified cdna clones for the enzymes PEL and cellulase and the objectives of this project are:
I ) To determine the effect of reduced PEL and cellulase activity on fruit qual and cell wall biochemistry. This will be achieved by the generation of transgen tomato and strawberry fruit. Transgenic plants will be produced in which levels of these enzymes have been reduced using antisense technology.
2). The commercial relevance of these studies will be examined by field testing the transgenic plants for yield, pathogen resistance and for the storage and processing qualities of the fruit.
Three research groups from UK, Netherlands and Spain and two industries one SME from Spain and the multinational company Unilever will collaborate on this project. The project is planned to be carried out in 3 successive years. It is separated into different tasks depending on the expertise of the different groups, which are complementary at the research and technical levels. The results will contribute to the knowledge of fruit ripening and its possible control, and may lead to the development of new varieties with improved characteristic of quality and with potential for commercialisation. The results may also be extended in the future to other fruit crops of commercial importance within the EU.
Fields of science (EuroSciVoc)
CORDIS classifies projects with EuroSciVoc, a multilingual taxonomy of fields of science, through a semi-automatic process based on NLP techniques.
CORDIS classifies projects with EuroSciVoc, a multilingual taxonomy of fields of science, through a semi-automatic process based on NLP techniques.
- agricultural sciencesagriculture, forestry, and fisheriesagriculturehorticulturefruit growing
- natural scienceschemical sciencespolymer sciences
- natural sciencesbiological sciencesbiochemistrybiomoleculesproteinsenzymes
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Call for proposal
Data not availableFunding Scheme
CSC - Cost-sharing contractsCoordinator
08034 BARCELONA
Spain