Dataset Information

Insights into a key sulfite scavenger enzyme sulfite oxidase (SOX) gene in plants.

ABSTRACT: Sulfite oxidase (SOX) is a crucial molybdenum cofactor-containing enzyme in plants that re-oxidizes the sulfite back to sulfate in sulfite assimilation pathway. However, studies of this crucial enzyme are quite limited hence this work was attempted to understand the SOXs in four plant species namely, Arabidopsis thaliana, Solanum lycopersicum, Populus trichocarpa and Brachypodium distachyon. Herein studied SOX enzyme was characterized with both oxidoreductase molybdopterin binding and Mo-co oxidoreductase dimerization domains. The alignment and motif analyses revealed the highly conserved primary structure of SOXs. The phylogeny constructed with additional species demonstrated a clear divergence of monocots, dicots and lower plants. In addition, to further understand the phylogenetic relationship and make a functional inference, a structure-based phylogeny was constructed using normalized RMSD values in five superposed models from four modelled plant SOXs herein and one previously characterized chicken SOX structure. The plant and animal SOXs showed a clear divergence and also implicated their functional divergences. Based on tree topology, monocot B. distachyon appeared to be diverged from other dicots, pointing out a possible monocot-dicot split. The expression patterns of sulfite scavengers including SOX were differentially modulated under cold, heat, salt and high light stresses. Particularly, they tend to be up-regulated under high light and heat while being down-regulated under cold and salt stresses. The presence of cis-regulatory motifs associated with different stresses in upstream regions of SOX genes was thus justified. The protein-protein interaction network of AtSOX and network enrichment with gene ontology (GO) terms showed that most predicted proteins, including sulfite reductase, ATP sulfurylases and APS reductases were among prime enzymes involved in sulfite pathway. Finally, SOX-sulfite docked structures indicated that arginine residues particularly Arg374 is crucial for SOX-sulfite binding and additional two other residues such as Arg51 and Arg103 may be important for SOX-sulfite bindings in plants.

SUBMITTER: Filiz E

PROVIDER: S-EPMC5391365 | biostudies-literature | 2017 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Insights into a key sulfite scavenger enzyme sulfite oxidase (SOX) gene in plants.

Filiz Ertugrul E Vatansever Recep R Ozyigit Ibrahim Ilker II

Physiology and molecular biology of plants : an international journal of functional plant biology 20170322 2

Sulfite oxidase (SOX) is a crucial molybdenum cofactor-containing enzyme in plants that re-oxidizes the sulfite back to sulfate in sulfite assimilation pathway. However, studies of this crucial enzyme are quite limited hence this work was attempted to understand the SOXs in four plant species namely, Arabidopsis thaliana, Solanum lycopersicum, Populus trichocarpa and Brachypodium distachyon. Herein studied SOX enzyme was characterized with both oxidoreductase m ...[more]

PMID: 28461726

Similar Datasets

Project description:Drought adversely affects crop growth and yields. The cloning and characterization of drought- or abscisic acid (ABA)-inducible promoters is of great significance for their utilization in the genetic improvement of crop resistance. Our previous studies have shown that maize sulfite oxidase (SO) has a sulfite-oxidizing function and is involved in the drought stress response. However, the promoter of the maize SO gene has not yet been characterized. In this study, the promoter (ZmSOPro, 1194 bp upstream region of the translation initiation site) was isolated from the maize genome. The in-silico analysis of the ZmSOPro promoter identified several cis-elements responsive to the phytohormone ABA and drought stress such as ABA-responsive element (ABRE) and MYB binding site (MBS), besides a number of core cis-acting elements, such as TATA-box and CAAT-box. A 5' RACE (rapid amplification of cDNA ends) assay identified an adenine residue as the transcription start site of the ZmSO. The ZmSOPro activity was detected by β-glucuronidase (GUS) staining at nearly all developmental stages and in most plant organs, except for the roots in transgenic Arabidopsis. Moreover, its activity was significantly induced by ABA and drought stress. The 5'-deletion mutant analysis of the ZmSOPro in tobacco plants revealed that a 119-bp fragment in the ZmSOPro (upstream of the transcription start site) is a minimal region, which is required for its high-level expression. Moreover, the minimal ZmSOPro was significantly activated by ABA or drought stress in transgenic plants. Further mutant analysis indicated that the MBS element in the minimal ZmSOPro region (119 bp upstream of the transcription start site) is responsible for ABA and drought-stress induced expression. These results improve our understanding of the transcriptional regulation mechanism of the ZmSO gene, and the characterized 119-bp promoter fragment could be an ideal candidate for drought-tolerant gene engineering in both monocot and dicot crops.

Project description:In humans, sulfite is generated endogenously by the metabolism of sulfur containing amino acids such as methionine and cysteine. Sulfite is also formed from exposure to sulfur dioxide, one of the major environmental pollutants. Sulfite is used as an antioxidant and preservative in dried fruits, vegetables, and beverages such as wine. Sulfite is also used as a stabilizer in many drugs. Sulfite toxicity has been associated with allergic reactions characterized by sulfite sensitivity, asthma, and anaphylactic shock. Sulfite is also toxic to neurons and cardiovascular cells. Recent studies suggest that the cytotoxicity of sulfite is mediated by free radicals; however, molecular mechanisms involved in sulfite toxicity are not fully understood. Cytochrome c (cyt c) is known to participate in mitochondrial respiration and has antioxidant and peroxidase activities. Studies were performed to understand the related mechanism of oxidation of sulfite and radical generation by ferric cytochrome c (Fe3+ cyt c) in the absence and presence of H2O2. Electron paramagnetic resonance (EPR) spin trapping studies using 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) were performed with sulfite, Fe3+ cyt c, and H2O2. An EPR spectrum corresponding to the sulfite radical adducts of DMPO (DMPO-SO3-) was obtained. The amount of DMPO-SO3- formed from the oxidation of sulfite by the Fe3+ cyt c increased with sulfite concentration. In addition, the amount of DMPO-SO3- formed by the peroxidase activity of Fe3+ cyt c also increased with sulfite and H2O2 concentration. From these results, we propose a mechanism in which the Fe3+ cyt c and its peroxidase activity oxidizes sulfite to sulfite radical. Our results suggest that Fe3+ cyt c could have a novel role in the deleterious effects of sulfite in biological systems due to increased production of sulfite radical. It also shows that the increased production of sulfite radical may be responsible for neurotoxicity and some of the injuries which occur to humans born with molybdenum cofactor and sulfite oxidase deficiencies.

Dataset Information

Insights into a key sulfite scavenger enzyme sulfite oxidase (SOX) gene in plants.

Publications

Insights into a key sulfite scavenger enzyme sulfite oxidase (<i>SOX</i>) gene in plants.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets