Skip to main content

Molecular genetics of gibberellin feedback regulation

Objective



Research objectives and content
This project aimes at understanding gibberellin (GA) signal transduction by means of hormone signalling mutants, i, particular the negative feedback regulation of GA biosynthetic genes. The host laboratory has generated Arabidopsis mutant plants carrying two reporter genes under the control of the GA-repressible promoter from the ga5 gene. More recently, simile constructs were generated from the ga4 gene. Transient expression analysis by microparticle bombardment revealed the expression from the ga4 promoter, like ga5 was down regulated by application of active GAs, confirming that those two genes which encode enzymes involved in the GA biosynthetic pathway, are feedback regulated by this hormone. The proposed research consists of two major approaches to identify components controlling the expression of these genes: 1) mutagenesis and genetical analysis of the plants described above. Similar transgenic plants will also be generated with the ga4 constructs. 2) functional analysis of regulatoty elements in the ga4 and ga5 promoters by means of panicle bombardment and gel shift assay
Training content (objective, benefit and expected impact)
The applicant, who is already familiar with many techniques in molecular biology, will extend these skills by working with molecular genetic approaches new to his home laboratory. His present expertise will also be a great value to John Mundy's group and to the proposed cis-acting analyses.The data obtained during this study will potentially advance the understanding of the molecular mechanisms of GA signal transduction. Links with industry / industrial relevance (22)
The control of germination and vegetative size by GAs are of interest to the brewing industry and producers of cereal crops. John Mundy's group has links to European industrial partners of both kinds through the European project ERB BIO4-CT96 0621

Funding Scheme

RGI - Research grants (individual fellowships)

Coordinator

UNIVERSITY OF COPENHAGEN
Address
2A,oester Farimagsgade 2A
1353 Koebenhavn K/copenhaegen
Denmark