Project description:Nitrogen and light are two major regulators of plant metabolism and development. While genes involved in the control of each of these signals have begun to be identified, regulators that integrate gene responses to nitrogen and light signals have yet to be determined. Here, we evaluate the role of bZIP1, a transcription factor involved in light and nitrogen sensing, by exposing wild-type (WT) and bZIP1 T-DNA null mutant plants to a combinatorial space of N and L treatment conditions. We use ANOVA analysis combined with clustering and Boolean modeling, to evaluate the role of bZIP1 in mediating L and N signaling genome-wide.
Project description:To optimize access to nitrogen under limiting conditions, root systems must continuously sense and respond to local or temporal fluctuations in nitrogen availability. In Arabidopsis thaliana and several other species, external N levels that induce only mild deficiency stimulate the emergence of lateral roots and especially the elongation of primary and lateral roots. However, the identity of the genes involved in this coordination remains still largely elusive. In order to identify novel genes and mechanisms underlying nitrogen-dependent root morphological changes, we investigated time-dependent changes in the root transcriptome of Arabidopsis thaliana plants grown under sufficient nitrogen or under conditions that induced mild nitrogen deficiency.
Project description:Chloroplasts are the metabolically most active compartment of mature leaf cells. Their proteins are involved in essential cellular processes, such as photosynthesis, nitrogen fixation, and fatty acid synthesis. For this, chloroplast proteins have to associate with other fellow organellar proteins to form functional units, react to changing environmental conditions, or optimize efficiency of biochemical reactions. We here investigated chloroplast protein-protein interactions by a combination of complexome profiling and cross-linking mass spectrometry (CX-MS). Different detergents and MS settings were tested for developing a new workflow, which was found to produce data of improved quality when comparted to standard complexome profiling approaches. This procedure was applied to chloroplasts acclimated to increasing light intensities to investigate the role of protein-protein interactions in the adaption to these conditions.
Project description:Nitrogen and light are two major regulators of plant metabolism and development. While genes involved in the control of each of these signals have begun to be identified, regulators that integrate gene responses to nitrogen and light signals have yet to be determined. Here, we evaluate the role of bZIP1, a transcription factor involved in light and nitrogen sensing, by exposing wild-type (WT) and bZIP1 T-DNA null mutant plants to a combinatorial space of N and L treatment conditions. We use ANOVA analysis combined with clustering and Boolean modeling, to evaluate the role of bZIP1 in mediating L and N signaling genome-wide. Arabidopsis thaliana were growth on basal MS salts (custom-made; GIBCO) with 0.5 mM KNO3, 3 mM sucrose and 0.8% BactoAgar at pH 5.7. After 14 days under long-day (16 h light: 8 h dark) conditions with light intensity of 50 μE.m-2.s-1 and at 22°C, plants were transferred to new plates containing 20 mM KNO3 and 20 mM NH4NO3 (referred here as 1xN: concentrations in MS media) in the absence or presence of light for 2 h at the start of their light cycle.