Project description:Regulation of light absorption under variable light conditions is essential to optimize photosynthetic and acclimatory processes in plants. Light energy absorbed in excess has a damaging effect on chloroplasts and can lead to cell death. Therefore, plants have evolved protective mechanisms against excess excitation energy that include chloroplast accumulation and avoidance responses. One of the proteins involved in facilitating chloroplast movements in Arabidopsis thaliana is the J domain-containing protein required for chloroplast accumulation response 1 (JAC1). The function of JAC1 relates to the chloroplast actin filaments appearance and disappearance. So far, the role of JAC1 was studied mainly in terms of chloroplasts photorelocation. Here, we demonstrate that the function of JAC1 is more complex, since it influences the composition of photosynthetic pigments, the efficiency of photosynthesis, and the CO2 uptake rate. JAC1 has positive effect on water use efficiency (WUE) by reducing stomatal aperture and water vapor conductance. Importantly, we show that the stomatal aperture regulation is genetically coupled with JAC1 activity. In addition, our data demonstrate that JAC1 is involved in the fine-tuning of H2O2 foliar levels, antioxidant enzymes activities and cell death after UV-C photooxidative stress. This work uncovers a novel function for JAC1 in affecting photosynthesis, CO2 uptake, and photooxidative stress responses.
Project description:Genetically engineering Arabidopsis thaliana to express Isoprene Synthase (ISPS) leads to changes in expression of genes assoiated with many growth regulator signaling pathways and signaling networks involved in abiotic and biotic stress responses.
Project description:We performed chloroplast ChIP-seq (cpChIP-seq) to identify the possible DNA-binding sites of mTERF5 in Arabidopsis thaliana. To this end, we generated transgenic Arabidopsis plants expressing mTERF5 carrying an HA tag under the control of the CaMV 35S promoter. Then, We used the polyclonal antibody (abcam, ab9110, lot GR304617-8 ) against HA tag which conjugated to ChIP-Grade protein A/G agarose (Thermo scientific, 26161, lot QJ223903) to perform cpChIP assay. The obtained chromatin immunoprecipitated DNA of chloroplasts were used to build DNA libaries for high-throughput sequencing. Finally, we showed that three potenssial DNA regions across the chloroplast genome compared to the control group were enriched by mTERF5.
Project description:Using whole genome microarray (Affymetrix ATH1) we studied the transcriptional response of Arabidopsis thaliana to glyphosate (Roundup Original) herbicde that inhibits 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) enzyme and thus disrupts aromaticamino acid biosynthesis. Few genes related to defense and secondary metabolism were altered. Keywords: 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) inhibiting herbicide stress response
Project description:Arabidopsis thaliana is a well-established model system for the analysis of the basic physiological and metabolic pathways of plants. The presented model is a new semi-quantitative mathematical model of the metabolism of Arabidopsis thaliana. The Petri net formalism was used to express the complex reaction system in a mathematically unique manner. To verify the model for correctness and consistency concepts of network decomposition and network reduction such as transition invariants, common transition pairs, and invariant transition pairs were applied. Based on recent knowledge from literature, including the Calvin cycle, glycolysis and citric acid cycle, glyoxylate cycle, urea cycle, sucrose synthesis, and the starch metabolism, the core metabolism of Arabidopsis thaliana was formulated. Each reaction (transition) is experimentally proven. The complete Petri net model consists of 134 metabolites, represented by places, and 243 reactions, represented by transitions. Places and transitions are connected via 572 edges.