This proposal aims to identify functions of a regulatory gene family which control plant development and to use those functions to generate crop plants with improved characteristics.
Biotechnological modification of plant features such as flowering time, leaf area, height, growth habit, reproduction etc. requires the isolation of new genes and the determination of their roles in controlling these processes. Rather than addressing this need by concentrating on specific developmental stages, we will identify and characterise the functions of a gene family with the potential to influence all aspects of growth and development - the MADS-box genes (MBGs).
MBGs are regulatory transcription factors with a strong precedent for controlling plant development. They are involved in developmental decisions in all eukaryotes in which they have so far been found. Plants have more family members than either animals or yeasts and the known control functions of some of the plant genes include: floral organ identity, meristem determinacy and floral transition.
The full extent of the plant gene family is unknown, but individual members are expressed at all developmental stages and in a wide variety of tissues (see proposal Figure 1). MBGs share certain structural and functional properties which make them ideal candidates for biotechnological approaches to alter plant development. We will isolate all members of the MADS-box gene family from two model species, Antirrhinum and petunia, using both cDNA and genomic approaches to ensure saturation. The expression patterns of the genes will be determined and the gene functions will be knocked out using a fully operational and efficient PCR/transposon mutagenesis strategy, which is available for both species. The effects of single and multiple MBG knockouts will be determined by genetic analysis of the mutants obtained. This strategy has the potential to reveal functions which would not be amenable to classical genetic analyses. The combination of coordinated gene isolation and gene knockouts in two species is important, because it is through a comparison of gene functions that universal features and species specific modifications will be identified. This comparison will be further extended by the search for specific functions in a model monocot (rice) and by transgenic studies. Functions of likely agricultural importance will be assessed in transgenic studies and introduced into crop plants by the industrial partners. The proposal describes the approaches that will be taken to identify novel gene functions, the way in which investigation of the functions is to be divided amongst the partners to ensure complete coverage of the lifecycle and the provisions which have been made to estimate the degree of saturation, test the biotechnological utility of the functions and use them to create crops with improved characteristics.
Funding SchemeCSC - Cost-sharing contracts
4411 RB Rilland
6700 AA Wageningen