Project description:Isoprene is a well-studied volatile hemiterpene that protects plants from abiotic stress through mechanisms that are not fully understood. The antioxidant and membrane stabilizing potential of isoprene are the two most commonly invoked mechanisms. However, isoprene also affects phenylpropanoid metabolism, suggesting an additional role as a signaling molecule. In this study, microarray based gene expression profiling reveals widespread transcriptional reprogramming of Arabidopsis thaliana plants fumigated for 24 hrs with a physiologically relevant concentration of isoprene. Functional enrichment analysis of fumigated plants revealed enhanced heat- and light-stress-responsive processes in response to isoprene. Isoprene induced a network enriched in ERF and WRKY transcription factors, which may play a role in stress tolerance. The isoprene-induced upregulation of phenylpropanoid biosynthetic genes was specifically confirmed using quantitative reverse transcription polymerase chain reaction. These results support a role for isoprene as a signaling molecule, in addition to its possible roles as an antioxidant and membrane thermoprotectant.
Project description:Chromatin, in addition to its purely structural functions, is considered a major regulatory system coordinating various genetic networks in eukaryotes. Constant changes of gene expression programs are especially important for plants, which have to respond to environment by modulating their growth and development during whole lifetime. External and developmental signals can be transmitted through signaling cascades to chromatin remodeling complexes like SWI/SNF, which alter chromatin structure by moving, ejecting or restructuring nucleosomes. Genetic studies in Arabidopsis thaliana revealed that SWI/SNF chromatin remodeling complexes are critical for proper plant development and growth. Especially, BRM, a catalytic subunit of the complex, was shown to directly regulate several genes with important functions in leaf development, flowering initiation, as well as gibberellin and abscisic acid signaling. In this study, we profiled BRM global binding regions in Arabidopsis genome by ChIP-chip analysis. We found that BRM can bind to thousands of genes, many of which have key functions in hormone and stress signaling.
Project description:A Local Regulatory Network Around Three NAC Transcription Factors in Stress Responses and Senescence in Arabidopsis leaves (Dark Induced Senescence).
Project description:Microbes of the root-associated microbiome contribute to improve resilience and fitness of plants. In this study, the interaction between the salt stress tolerance-inducing beneficial bacterium Enterobacter sp. SA187 and Arabidopsis was investigated with a special focus on the plant immune system. Among the immune signalling mutants, the Lys-motif receptors LYK4 strongly affected the beneficial interaction. Overexpression of the chitin receptor components LYK4 compromised the beneficial effect of SA187 on Arabidopsis. Transcriptome analysis revealed that the role of LYK4 in immunity is intertwined with a function in remodeling defense responses. Overall, our data indicate that components of the plant immune system are key elements in mediating beneficial metabolite-induced plant abiotic stress tolerance.
Project description:CAF-1 is a major nucleosome assembly complex, which functions particularly during replication and DNA-repair. Here, we studied how the nucleosome landscape changes in fas2 a mutant of the CAF-1 complex in the model plant Arabidopsis thaliana