Objective
This proposal aims to elucidate early steps in the development of the maize embryo. Combining genetics, cytology, molecular biology and plant tissue culture the participating laboratories propose firstly to isolate and characterise novel genes essential for embryo development, secondly to analyse phytohormone signalling in embryos and lastly to alter embryo size and quality according to industrial demands.
Two complementary approaches will be followed to isolate novel genes. Firstly genes mutated by transposon insertion will be cloned from lines with abnormal embryo development (WP 1). Secondly genes which are transcribed only during specific stages of embryo development or only in specific parts of the embryo will be isolated by differential display (WP 2). Gene characterization will include the molecular analysis of the genes as well as a detailed description of corresponding mutants. While mutants will be the starting point in the first approach, they will be created via reverse genetics for the second group. The molecular characterization will involve the determination of the temporal and spatial expression pattern, of the nucleotide sequence and of the map position in the maize genome. Gene expression in specific regions of the developing embryo, homologies to known proteins or a co- segregation with known genes may already give clues to the function of the genes and will direct the choice of clones for a more detailed functional analysis.
For these the cytological and molecular characterization of the mutant phenotype in planta will be complemented by attempts to alter or restore the development of mutant embryos in-vitro. Since many developmental steps are common to zygotic and somatic embryogenesis and may be rate limiting in the regeneration and transformation of maize the expression of all isolated genes will also be monitored in somatic embryos.
Recently established in-vitro systems allow studies of single embryos independently of surrounding maternal tissues. To analyse the influence of signal molecules like hormones or ions during embryogenesis isolated embryos will be treated with auxins, inhibitors of auxin transport or auxin receptors as well as of modulators of calcium fluxes (WP 3). These manipulations will be performed in wildtype embryos as well as in selected mutant embryos. Finally the transient and stable expression of embryo specific promoter fusions to reporter genes will help our understanding of gene regulation and possibly elucidate links between signal molecules and gene expression. In an industrial context the oil rich embryo and the starch rich endosperm are the two economically interesting parts of the maize seed. To meet demands of the processing industry we propose to exploit embryo specific promoters in the production of oil rich and embryo less maize lines (WP 4).
The outlined multi-disciplinary approach will significantly contribute to the understanding of grass embryo development and open new ways for the possible improvement of plant regeneration from in-vitro cultures and the engineering of maize embryos according to applied demands.
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.
- natural sciencesbiological sciencesdevelopmental biology
- medical and health sciencesbasic medicinephysiologycytology
- natural sciencesmathematicspure mathematicsmathematical analysisfunctional analysis
- medical and health sciencesclinical medicineembryology
- natural sciencesbiological sciencesmolecular biology
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Call for proposal
Data not availableFunding Scheme
CSC - Cost-sharing contractsCoordinator
69364 Lyon
France