Genome Plasticity

Group Leader: [link]PD Dr. Renate Schmidt

Publications : [link]Link

Research Interest

Genetic analysis of seed traits in Arabidopsis thaliana

We are interested to study genetic factors with an impact on the trait seed yield in Arabidopsis thaliana. Populations of recombinant inbred lines and near-isogenic lines are used to determine characters such as seed weight, seed size, seed number per silique and seed yield per plant. Loci of importance for these traits are identified via the mapping of quantitative trait loci. In order to gain a first insight which factors may underlie the traits of interest, genome-wide transcript profiles at a defined stage of seed development were established for recombinant inbred lines and used for the identification of gene expression QTL. These activities contribute to the IPK research theme FSP4 “Growth and metabolism”.

Transgene silencing in Arabidopsis thaliana

Silencing of introduced genes is often observed in transgenic plants. A systematic analysis of transgene expression in Arabidopsis thaliana showed that post-transcriptional transgene silencing is triggered by excessive transcript levels (S-PTGS). The transgene expression level correlates with the probability that S-PTGS is initiated early in plant development. The study of progeny of plants with silenced transgenes showed that the silenced state is not transmitted to the next generation, instead silencing has to be established in each generation anew. In order to study the impact of natural variation on this process, sequence variation of genes involved in S-PTGS and/or other RNA silencing pathways is surveyed. Moreover, monitoring of S-PTGS in introgression lines is used for the identification and characterisation of silencing modulators in Arabidopsis thaliana accession genomes.

The impact of duplications in the oilseed rape genome

Polyploidy is widespread in the plant kingdom. We are therefore interested to trace the fate of duplicated regions in the course of evolution. We use the allopolyploid species Brassica napus (oilseed rape) to study the arrangement, structure and expression of duplicated genes in selected regions of the rapeseed genome. A PCR-based screening platform of an oilseed rape BAC library enables quick access to regions of interest in the rapeseed genome. Furthermore, we determine the allelic diversity of selected genes in a broad set of oilseed rape accessions.