Phytoremediation of toxic metals from soil and waste water

Abstract: Phytoremediation is an emerging technology, which uses plants and their associated rhizospheric microorganisms to remove pollutants from contaminated sites. This plant based technology has gained acceptance in the past ten years as a cheap, efficient and environment friendly technology especially for removing toxic metals. Plant based technologies for metal decontamination are extraction, volatilization, stabilization and rhizofiltration. Various soil and plant factors such as soil's physical and chemical properties, plant and microbial exudates, metal bioavailability, plant's ability to uptake, accumulate, translocate, sequester and detoxify metal amounts for phytoremediation efficiency. Use of transgenics to enhance phytoremediation potential seems promising. Despite several advantages, phytoremediation has not yet become a commercially available technology. Progress in the field is hindered by lack of understanding of complex interactions in the rhizosphere and plant based mechanisms which allow metal translocation and accumulation in plants. The review concludes with suggestions for future phytoremediation research

Purification and partial characterization of oxalate oxidase from leaves of forage Sorghum (<i style="">Sorghum vulgare</i> var. KH-105) seedlings

42-46An oxalate oxidase was purified to apparent homogeneity from the leaves of 10-days old seedlings of forage Sorghum (Sorghum vulgare var. KH-105). The enzyme had a Mr of 124 kDa with two identical subunits, an optimum pH of 4.5, optimum temperature of 37°C and activation energy (Ea) of 2.0338 Kcal/mol. The rate of reaction was linear up to 7 min. Km value for oxalate was 0.22 mM. The enzyme was stimulated by Cu2+ and inhibited by EDTA, NaCN, diethyldithiocarbamate, na2SO4, but unaffected by NaCl at 0.1 mM concentration. Although the enzyme was stimulated by flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), UV and visible spectra of the enzyme did not match with that of a flavoprotein. The positive reaction of the enzyme with orcinol-H2SO4 reagent indicated its glycoprotein nature. The superiority of the purified enzyme over earlier reported oxalate oxidases for determination of urinary oxalate has been demonstrated

Not Available

Not AvailableTotal phenol content, peroxidase and polyphenol oxidase contents were estimated in maize germplasm affected by banded leaf and sheath blight disease. In comparison to healthy plants, the increase in total phenol content in diseased plants was maximum in extra early germplasm (362.3%) followed by inbreds (353.06%). Contrarily, peroxidase level increase was maximum in early maturity germplasm (87.5%) followed by inbred (86.0%). The relative increase in polyphenol oxidase was maximum in early maize germplasm (70.8%) followed by inbreds (63.7%). These are secretions which require trigger by means of pathogen attack, elicitor response and abiotic stresses. It appears that higher phenol, peroxidase and polyphenol oxidase activities in maize germplasm plays a vital role in inducing resistance against banded leaf and sheath blight (BLSB) disease in maize.Not Availabl

Nano-Iron and Nano-Zinc Induced Growth and Metabolic Changes in <i>Vigna radiata</i>

The widespread industrial use and consequent release of nanosized iron (nFe3O4) and zinc oxide (nZnO) particles into the environment have raised concerns over their effects on living organisms, including plants. These nanoparticles are the source of their respective metal ions and although plants require both Fe and Zn ions for proper growth, excessive levels of these metals are toxic to them. A better understanding of the effects of these nanoparticles on plants also offers an opportunity for their useful applications in agriculture. The present work evaluates the changes in seed germination, plant growth, photosynthetic capacity, levels of biomolecules and antioxidant enzymes in Vigna radiata (L.) Wilczek when grown in the presence of nFe3O4 (size 1–4 nm) and nZnO (size 10–20 nm) and compared to the control plants. The plants were raised hydroponically for up to 14 days at two different concentrations of nanoparticles, viz. 10 and 100 mg/L. Inductively coupled plasma mass spectrometry (ICP-MS) results established that V. radiata can accumulate Fe and Zn in shoots with high efficiency. The results indicated that nFe3O4 had a favourable effect on V. radiata, whereas no apparent benefit or toxicity of nZnO was observed at the tested concentrations

Nano-Iron and Nano-Zinc Induced Growth and Metabolic Changes in Vigna radiata

The widespread industrial use and consequent release of nanosized iron (nFe3O4) and zinc oxide (nZnO) particles into the environment have raised concerns over their effects on living organisms, including plants. These nanoparticles are the source of their respective metal ions and although plants require both Fe and Zn ions for proper growth, excessive levels of these metals are toxic to them. A better understanding of the effects of these nanoparticles on plants also offers an opportunity for their useful applications in agriculture. The present work evaluates the changes in seed germination, plant growth, photosynthetic capacity, levels of biomolecules and antioxidant enzymes in Vigna radiata (L.) Wilczek when grown in the presence of nFe3O4 (size 1&ndash;4 nm) and nZnO (size 10&ndash;20 nm) and compared to the control plants. The plants were raised hydroponically for up to 14 days at two different concentrations of nanoparticles, viz. 10 and 100 mg/L. Inductively coupled plasma mass spectrometry (ICP-MS) results established that V. radiata can accumulate Fe and Zn in shoots with high efficiency. The results indicated that nFe3O4 had a favourable effect on V. radiata, whereas no apparent benefit or toxicity of nZnO was observed at the tested concentrations

Early loss of Histone H2B monoubiquitylation alters chromatin accessibility and activates key immune pathways that facilitate progression of ovarian cancer.

Recent insights supporting the fallopian tube epithelium (FTE) and serous tubal intraepithelial carcinomas (STIC) as the tissue of origin and the precursor lesion, respectively, for the majority of high-grade serous ovarian carcinomas (HGSOC) provide the necessary context to study the mechanisms that drive the development and progression of HGSOC. Here we investigate the role of the E3 ubiquitin ligase RNF20 and histone H2B monoubiquitylation (H2Bub1) in serous tumorigenesis and report that heterozygous loss of RNF20 defines the majority of HGSOC tumors. At the protein level, H2Bub1 was lost or downregulated in a large proportion of STIC and invasive HGSOC tumors, implicating RNF20/H2Bub1 loss as an early event in the development of serous ovarian carcinoma. Knockdown of RNF20, with concomitant loss of H2Bub1, was sufficient to enhance cell migration and clonogenic growth of FTE cells. To investigate the mechanisms underlying these effects, we performed ATAC-seq and RNA-seq in RNF20 knockdown FTE cell lines. Loss of RNF20 and H2Bub1 was associated with a more open chromatin conformation leading to upregulation of immune signaling pathways, including interleukin 6 (IL6). IL6 was one of the key cytokines significantly upregulated in RNF20- and H2Bub1-depleted FTE cells and imparted upon these cells an enhanced migratory phenotype. These studies provide mechanistic insight into the observed oncogenic phenotypes triggered by the early loss of H2Bub1