Project description:Melioribacter roseus is one of two cultured representatives of the phylum Ignavibacteriae. It could grow by fermentation of sugars and peptides, by aerobic respiration or by dissimilatory reduction of arsenate, nitrite or Fe(III) on fermentable and non-fermentable substrates, what allows this bacterium to adapt to fluctuating environmental conditions. Primary genome analysis highlighted key determinants of electron transport chains, providing important insights into the ability of M. roseus to use a range of electron acceptors. Complete set of genes for proton-translocating membrane complexes I and II, alternative complex III (ACIII) and seven terminal oxidoreductases was found in the M. roseus genome. Among those three different cytochrome oxidases and two different molybdopterin oxidoreductases have been proposed to determine two most active respiratory processes performed by M. roseus – aerobic respiration and dissimilatory arsenate reduction, respectively.
Project description:Stress constantly challenges plant adaptation to the environment. Of all stress types, arsenic was a major threat during the early evolution of plants. The most prevalent chemical form of arsenic is arsenate, whose similarity to phosphate renders it easily incorporated into cells via the phosphate transporters. Here we found that arsenate stress provokes a notable transposon burst in plants, in coordination with arsenate/phosphate transporter repression, which immediately restricts arsenate uptake. This repression was accompanied by delocalization of the phosphate transporter from the plasma membrane. When arsenate was removed, the system rapidly restored transcriptional expression and membrane localization of the transporter. We identify WRKY6 as an arsenate-responsive transcription factor that mediates arsenate/phosphate transporter gene expression and restricts arsenate-induced transposon activation. Plants therefore have a dual WRKY-dependent signaling mechanism that modulates arsenate uptake and transposon expression, providing a coordinated strategy for arsenate tolerance and transposon gene silencing.
2014-04-25 | GSE49037 | GEO
Project description:From arsenic-polluted sediments to sulfate/arsenate-reducing bacterial consortia
