Project description:Maintenance of the root-meristem is determined by polar auxin transport (PAT) and asymmetric cell division (ACD). We find that flavonoids scutellarin and scutellarein, which both have 6-hydroxyl group that differs in its structure from all known-flavonoid PAT inhibitors, promote PAT and ACD in Arabidopsis thaliana root tip, and increase root length. We used microarrays to detail the global programme of gene expression under scutellarin and mock (DMSO) treatment and identified distinct classes of genes regulated by scutellarin.
Project description:transcripomics on the arabidopsis root tip during phosphate starvation-Transcripomics on the Arabidopsis Root tip during phosphate starvation
Project description:Plant roots located in the upper soil layers are prone to experience high temperatures. To gain insight into the effect of high temperature on root development and functioning, we exposed five-day-old Arabidopsis thaliana seedlings grown on agar plates to 30 °C for 48 hours, and compared the gene expression profile in the root tip with that from seedlings that remained at 22 °C.
Project description:The balance between cell proliferation, differentiation and elongation rates emerges from gene regulatory networks coupled to various signal transduction pathways, including reactive oxygen species (ROS) and transcription factors, to respond to environmental cues. The Arabidopsis thaliana primary root has become a valuable system to unravel such networks and the role of transcription factors mediating the inhibition of primary root growth by ROS is just beginning to be studied. In this study, we demonstrate that the MADS-box transcription factor XAANTAL1 (XAL1) mediates the role of hydrogen peroxide (H2O2) in primary root growth and root stem cell niche identity. Interestingly, our findings suggest that XAL1 acts as a positive regulator of H2O2 concentration in the root meristem by directly regulating genes involved in oxidative stress response, such as PEROXIDASE 28 (PER28). Moreover, we found that XAL1 is necessary for the H2O2-induced inhibition of primary root growth through the negative regulation of peroxidase and catalase activities. Furthermore, we found that XAL1 together with RETINOBLASTOMA-RELATED (RBR), is also necessary to positively regulate the differentiation of columella stem cells triggered by a moderate oxidative stress induced by H2O2 treatment.
