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:Arabidopsis thaliana is a glycophyte with a low salt tolerance, while Eutrema is a halophyte with a very high salt tolerance. To elucidate the transcriptional basis of this difference, we performed hydroponis culture experiments where we grew plants under control conditions (25 mM NaCl) or under salt stress (200 mM NaCl for both species, 500 mM for Eutrema). Salt concentration was increased for the stress treatments by increments of 50 mM per day (25 mM on the first day). Plants were grown at the final NaCl concentration for an additional week, when rosettes were harvested for RNA isolation.Expression patterns were compared between treatments and between species.
Project description:The ALADIN protein is a component of the nuclear pore complex in higher eukaryotes. Alteration in ALADIN is the basis for the human disease called triple A syndrome (Achalasia-Addisonianism-Alacrima Syndrome). A recent report showed that ALADIN deficiency decreases the tolerance to oxidative stress in human cells and impairs their ability to proliferate. An ALADIN homologue exists in plants, but its functions are still unknown. Therefore, the role of ALADIN was investigated in Arabidopsis thaliana in link with the regulation of the cell cycle. Transcriptome profiling of the roots and shoots of the aladin mutant showed the induction of numerous transcripts linked to stress response and hormone signalling.
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. Plants were held at 23 °C for 24 hours and then held at 40 °C for 24 hours, either in the presence or absence of 20 PPM isoprene during the entire 48 hours. Leaf samples were taken at the end of both 24 hour treatment periods. Each of the 4 resulting conditions was replicated 3 times.
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.