ABSTRACT: Gene expression analysis (RNA-seq) of Arabidopsis thaliana roots in wild type and trm4b-1 mutants under control and oxidative stress conditions
Project description:To investigate why Arabidopsis trm4b mutants have short roots and increased sensitivity to oxidative stress, we investigated gene expression in wild type and trm4b-1 mutants under control and oxidative stress conditions
Project description:Phototropins are plasma membrane‐associated photoreceptors of blue light. Arabidopsis thaliana genome has two genes, PHOT1 and PHOT2, encoding two phototropins that mediate phototropism, chloroplast positioning and stomatal opening. They are well characterized in terms of photomorphogenetic processes, but so far little was known about their involvement in photosynthesis and response to stress factors triggering oxidative stress and cell death. This work fills the gap in our understanding of PHOT1 and PHOT2 involvement in these processes. We used UV-C treatment to promote oxidative stress and cell death in Arabidopsis thaliana wild-type (Col-0 gl1), phot1, phot2 and phot1/phot2 mutants. Using RNAseq we identified genes differentially expressed in phot mutants, in comparison to the wild-type, in both non-stress conditions and after UV-C stress.
Project description:RNAseq transcriptome of leaves and roots of Arabidopsis thaliana Columbia-0 grown under control (ES media) and Fe-deficiency (-Fe +100 µM FRZ) conditions.
Project description:Transcriptional profiling of Arabidopsis thaliana seedlings comparing overexpressor with wild type, and knockout with wild type separately under control and NaCl stress.
Project description:Nontargeted and targeted metabolomics measurements of abiotic stress responses in three-week-old Arabidopsis thaliana plants' rosette leaf tissue for Col-0 wild type plants and double/triple knockout mutants of aquaporins (pip2;1 pip2;2 and pip2;1 pip2;2 pip2;4) treated with drought, heat at different air humidities, or combined drought-heat stress at different air humidities. This experiment contains FT-ICR-MS measurements for 103 Arabidopsis thaliana rosette leaf samples covering three genotypes under six different environmental conditions. The three genotypes comprise the Col-0 wildtype and two loss-of-function mutants of aquaporins, a pip2;1 pip2;2 double mutant and a pip2;1 pip2;2 pip2;4 triple mutant (respective AGI locus identifiers: AT3G53420, AT2G37170, AT5G60660). The six conditions include control condition (well-watered, 22 °C, 70% relative air humidity), drought stress (one week without watering), heat stress without changing the absolute humidity of the ambient air (6 hours at 33 °C, 37% relative air humidity), heat stress with supplemented air humidity to maintain a constant vapor pressure deficit before and during the heat episode (6 hours at 33 °C, 84% relative air humidity), and the combinations of drought pretreatment with each of the two heat stress variants (one week of drought followed by 6 hours of heat stress). Samples from all conditions were harvested at the same time (within 15 min starting at 5 pm). For validation, GC-TOF-MS measurements were done for two genotypes (wildtype, double mutant) and two conditions (drought, control) on partially overlapping samples.
Project description:CuZn-superoxide dismutase (CuZn-SOD) and ascorbate peroxidase (APX) constitute first line of defence against oxidative stress. In the present study, PaSOD and RaAPX genes from Potentilla atrosanguinea and Rheum australe, respectively were overexpressed individually as well as in combination in Arabidopsis thaliana. We performed RNA-seq analysis of wild type and transgenic Arabidopsis thaliana overexpressing CuZn-SOD, APX and CuZn-SOD + APX under control and salt stress
Project description:Background: Polycyclic aromatic hydrocarbons (PAHs) are toxic, widely-distributed, environmentally persistent, and carcinogenic byproducts of carbon-based fuel combustion. Previously, plant studies have shown that PAHs induce oxidative stress, reduce growth, and cause leaf deformation as well as tissue necrosis. To understand the transcriptional changes that occur during these processes, we performed microarray experiments on Arabidopsis thaliana L. under phenanthrene treatment, and compared the results to published Arabidopsis microarray data representing a variety of stress and hormone treatments. In addition, to probe hormonal aspects of PAH stress, we assayed transgenic ethylene-inducible reporter plants as well as ethylene pathway mutants under phenanthrene treatment. Results: Microarray results revealed numerous perturbations in signaling and metabolic pathways that regulate reactive oxygen species (ROS) and responses related to pathogen defense. A number of glutathione S-transferases that may tag xenobiotics for transport to the vacuole were upregulated. Comparative microarray analyses indicated that the phenanthrene response was closely related to other ROS conditions, including pathogen defense conditions. The ethylene-inducible transgenic reporters were activated by phenanthrene. Mutant experiments showed that PAH inhibits growth through an ethylene-independent pathway, as PAH-treated ethylene-insensitive etr1-4 mutants exhibited a greater growth reduction than WT. Further, phenanthrene-treated, constitutive ethylene signaling mutants had longer roots than the untreated control plants, indicating that the PAH inhibits parts of the ethylene signaling pathway. Conclusions: This study identified major physiological systems that participate in the PAH-induced stress response in Arabidopsis. At the transcriptional level, the results identify specific gene targets that will be valuable in finding lead compounds and engineering increased tolerance. Collectively, the results open a number of new avenues for researching and improving plant resilience and PAH phytoremediation. Arabidopsis thaliana (ecotype Columbia) plants were long-day grown with +/- 0.25 mM phenanthrene in sterile plates at 23C for 21d before harvest. At least 20 plants were pooled prior to each mRNA extraction.
Project description:Diphthamide, a post-translationally modified histidine residue of eukaryotic TRANSLATION ELONGATION FACTOR2 (eEF2), is the human host cell-sensitizing target of diphtheria toxin. Diphthamide biosynthesis depends on the 4Fe-4S-cluster protein Dph1 catalyzing the first committed step, as well as Dph2 to Dph7, in yeast and mammals. Here we show that diphthamide modification of eEF2 is conserved in Arabidopsis thaliana and requires AtDPH1. Ribosomal -1 frameshifting-error rates are increased in Arabidopsis dph1 mutants, similar to yeast and mice. Compared to the wild type, shorter roots and smaller rosettes of dph1 mutants result from fewer formed cells. TARGET OF RAPAMYCIN (TOR) kinase activity is attenuated, and autophagy is activated, in dph1 mutants. Under abiotic stress diphthamide-unmodified eEF2 accumulates in wild-type seedlings, most strongly upon heavy metal excess, which is conserved in human cells. In summary, our results suggest that diphthamide contributes to the functionality of the translational machinery monitored by plants to regulate growth.
Project description:We performed a transcriptomic analysis of Pi starvation responses in Arabidopsis thaliana (Columbia-0) wild type plants under phosphate starvation stress and in plants with altered PHR1(-like) activity, comparing mutants of phr1 and phr1-phl1 grown in phosphate-lacking medium. Results show the central role of PHR1 and functionally redundant members of its family in the control of transcriptional responses to Pi starvation.
Project description:We analyzed the dynamics of changes in the level of DNA methylation in Arabidopsis thaliana under the influence of heat stress. For this purpose whole-genome sequencing of sodium bisulfite treated DNA was performed. The analysis was carried out at seven time points taking into account control conditions, heat stress and return to control conditions after stopping stress treatment. The analysis showed that under the influence of heat stress there is a global decrease in the level of DNA methylation in Arabidopsis thaliana in all three sequence contexts (CpG, CHG, CHH).