Project description:Here we investigate the function of CUC1(CUP-SHAPED COTYLEDON1) in the diversification of leaf forms between simple-leaved Arabidopsis thaliana and compound-leaved Cardamine hirsuta. CUC transcription factors are conserved regulators in leaf margin dissection and leaflet formation. ChCUC1, ChCUC2 and ChCUC3 function redundantly and are required for the leaflet formation in C. hirsuta. Recently we discovered that ChCUC1 has species species-specific expression in young leaves of C.hirsuta. Moreover, interspecies gene transfer of ChCUC1 allele into A.thaliana is sufficient to increase leaf complexity. On this basis, we hypothesize that redeployment of ChCUC1 in leaves contributes to the formation of leaflets instead of serrations. However, the mechanism underlying ChCUC1 regulating cell division, cell polarity, cytoskeleton and thus leaf marginal patterning remains elusive. To this end, we make use of chromatin immunoprecipitation sequencing(ChIP-seq), transcriptomic, comparative genetics and advanced imaging approaches to identify the downstream regulating genes of ChCUC1.
Project description:To understand allopoyploid speciation into hydrologically fluctuating niches, we observed gene expressions of two parental species and their allotetraploid species under wet and dry conditions Gene expression of leafs from control, dry and wet conditions over three Caramine species: C. amara, C. hirsuta and C. flexuosa
Project description:Pot grown plants of Arabidopsis thaliana, Cardamine hirsuta, Cardamine pratensis, Rorippa palustris and Rorippa sylvestris where completely submerged under ambient light conditions. After 24 and 48 hours the shoots were harvested for expression analysis. Differential expression analysis, taking into account unsubmerged control plants revealed that the Rorippa genus had a pronounced down regulation of the cell cycle whereas the Cardamine had an attenuated response to submergence.
Project description:Floral development is remarkably robust in terms of the identity and number of floral organs in each whorl, whereas vegetative development can be quite plastic. This canalization of flower development prevents the phenotypic expression of cryptic genetic variation, even in fluctuating environments. A cruciform perianth with four petals is a hallmark of the Brassicaceae family, typified in the model species Arabidopsis thaliana However, variable petal loss is found in Cardamine hirsuta, a genetically tractable relative of A. thaliana Cardamine hirsuta petal number varies in response to stochastic, genetic and environmental perturbations, which makes it an interesting model to study mechanisms of decanalization and the expression of cryptic variation.Multitrait quantitative trait locus (QTL) analysis in recombinant inbred lines (RILs) was used to identify whether the stochastic variation found in C. hirsuta petal number had a genetic basis.Stochastic variation (standard error of the average petal number) was found to be a heritable phenotype, and four QTL that influenced this trait were identified. The sensitivity to detect these QTL effects was increased by accounting for the effect of ageing on petal number variation. All QTL had significant effects on both average petal number and its standard error, indicating that these two traits share a common genetic basis. However, for some QTL, a degree of independence was found between the age of the flowers where allelic effects were significant for each trait.Stochastic variation in C. hirsuta petal number has a genetic basis, and common QTL influence both average petal number and its standard error. Allelic variation at these QTL can, therefore, modify petal number in an age-specific manner via effects on the phenotypic mean and stochastic variation. These results are discussed in the context of trait evolution via a loss of robustness.
Project description:We used RNA-seq to profile gene expression changes during flg22 activated pattern-triggered immunity in multiple Brassicaceae including Capsella rubella, Cardamine hirsuta and Eutrema salsugineum as well as in multiple Arabidopsis thaliana accessions. This allows comparative transcriptomics within and across species to investigate the evolution of stress-responsive transcrption changes in these species.