Project description:Selenate is chemically similar to sulfate and can be taken up and assimilated by plants via the same transporters and enzymes. In contrast to many other organisms, selenium (Se) has not been shown to be essential for higher plants. In excess, Se is toxic and restricts development. Both Se deficiency and toxicity pose problems worldwide. To obtain better insight into the effects of Se on plant metabolism and into plant mechanisms involved in Se tolerance, the transcriptome of Arabidopsis plants grown with or without selenate was studied, and Se-responsive genes identified. Roots and shoots exhibited different Se-related changes in gene regulation and metabolism. Many genes involved in sulfur (S) uptake and assimilation were upregulated. Accordingly, Se treatment enhanced sulfate levels in plants, but the quantity of organic S metabolites decreased. Transcripts regulating the synthesis and signaling of ethylene and jasmonic acid were also upregulated by Se. Selenate appeared to repress plant development, as suggested by the down-regulation of genes involved in cell wall synthesis and auxin-regulated proteins. The Se-responsive genes discovered in this study may help create plants that can better tolerate and accumulate Se, which may enhance the effectiveness of Se phytoremediation or serve as Se-fortified food. Keywords: selenate, abiotic stress
Project description:Selenate is chemically similar to sulfate and can be taken up and assimilated by plants via the same transporters and enzymes. In contrast to many other organisms, selenium (Se) has not been shown to be essential for higher plants. In excess, Se is toxic and restricts development. Both Se deficiency and toxicity pose problems worldwide. To obtain better insight into the effects of Se on plant metabolism and into plant mechanisms involved in Se tolerance, the transcriptome of Arabidopsis plants grown with or without selenate was studied, and Se-responsive genes identified. Roots and shoots exhibited different Se-related changes in gene regulation and metabolism. Many genes involved in sulfur (S) uptake and assimilation were upregulated. Accordingly, Se treatment enhanced sulfate levels in plants, but the quantity of organic S metabolites decreased. Transcripts regulating the synthesis and signaling of ethylene and jasmonic acid were also upregulated by Se. Selenate appeared to repress plant development, as suggested by the down-regulation of genes involved in cell wall synthesis and auxin-regulated proteins. The Se-responsive genes discovered in this study may help create plants that can better tolerate and accumulate Se, which may enhance the effectiveness of Se phytoremediation or serve as Se-fortified food. Experiment Overall Design: Arabidopsis thaliana (ecotype WS) plants were vertically grown on +/- 40 micromolar selenate MS medium. Root and shoot tissues of 10-day-old plants were seperated and used for RNA extraction and hybridization on Affymetrix microarrays. All conditions were duplicated.
Project description:ABSTRACT: Natural variation allows the investigation of both the fundamental functions of genes and their role in local adaptation. As one of the essential macronutrients, sulfur is vital for plant growth and development, and also for crop yield and quality. Selenium and sulfur are assimilated by the same process, and although plants do not require selenium, plant-based selenium is an important source of this essential element for animals. Here, we report the use of linkage mapping in synthetic F2 populations, and complementation to investigate the genetic architecture of variation in total leaf sulfur and selenium concentrations in a diverse set of Arabidopsis thaliana accessions. We identify in accessions collected from Sweden and the Czech Republic two variants of the enzyme adenosine 5-phosphosulfate reductase 2 (APR2) with strongly diminished catalytic capacity. APR2 is a key enzyme in both sulfate and selenate reduction and its reduced activity in the loss-of-function allele apr2-1 and the two A. thaliana accessions Hodon¨ªn (Hod) and Shahdara (Sha), leads to a lowering of sulfur flux from sulfate into the reduced sulfur compounds, cysteine and glutathione, and into proteins, concomitant with an increase in the accumulation of sulfate in leaves. We conclude from our observation, and the previously identified weak allele of APR2 from the Sha accession collected in Tadjikistan, that the catalytic capacity of APR2 varies by four orders of magnitude across the A. thaliana species range, driving significant differences in sulfur and selenium metabolism. The selective benefit, if any, of this large variation remains to be explored.
2014-10-01 | GSE61922 | GEO
Project description:Methane-supported selenate reduction under oxygen-limiting condition
Project description:This SuperSeries is composed of the following subset Series: GSE8015: Pyruvate fermentation vs Lactate-Sulfate GSE8037: Hydrogen vs Lactate as electron donor in Sulfate reduction GSE8071: Pyruvate vs Lactate as electron donor in Sulfate reduction GSE8072: Thiosulfate vs Sulfate as electron acceptor in Sulfate reduction Keywords: SuperSeries Refer to individual Series