Microarray analysis of Arabidopsis under gold exposure to identify putative genes involved in the synthesis of gold nanoparticles (AuNPs)

AbstractVery little is known about the genes responsible for Au uptake, reduction and detoxification in plants, which indeed essential to understand the complex trait of AuNP biosynthesis. We designed a targeted experiment to elucidate the response of plant at transcriptional level under Au exposure, and a microarray was performed on root tissue treated with AuCl4− in the absence of nutrient media to record specific gene expression signature. Here, we describe the experimental procedures and data analysis in detail to reproduce the results (available at GEO database under GSE55436) published by Shukla et al. (2014) [1] in the Frontiers in Plant Sciences. The data produced from this study provide significant information of genes which may be used to enhance the AuNP biosynthesis

Differential responses of Duo grass (Lolium × Festuca), a phosphorus hyperaccumulator to high phosphorus and poultry manure treatments

Use of suitable plants to extract and concentrate excess phosphorus (P) from contaminated soil serves as an attractive method of phyto-remediation. Plant species vary considerably in their potential to assimilate different organic and inorganic P substrates. Duo grass (a hybrid of Lolium × Festuca) seedlings were grown in liquid nutrient media supplemented with various concentrations of potassium dihydrogen phosphate (KH2PO4) and phytate to study their P-accumulation potential. Plants that received extra P showed significantly greater plant biomass and accumulated more shoot P compared to the plants that were supplied with normal P. Duo was also grown in poultry manure amended soil and liquid media to evaluate their ability to grow and accumulate biomass in poultry manure impacted soils. Thus this grass species may be utilized as a P hyper-accumulator for phyto-extraction of excess P into their biomass from soils. Duo grass can utilize both organic (phytate), as well as, inorganic P from the growth medium as evidenced in the results.Keywords: Duo grass, phosphorus, phosphorus substrates, phytate, phosphorus accumulation, phytoremediationAfrican Journal of Biotechnology Vol. 12(21), pp. 3191-319

Comparative transcriptome and proteome analysis to reveal the biosynthesis of gold nanoparticles in Arabidopsis

© 2016, Nature Publishing Group. All rights reserved. A large number of plants have been tested and exploited in search of a green chemistry approach for the fabrication of gold or other precious metal nanomaterials. Despite the potential of plant based methods, very little is known about the underlying biochemical reactions and genes involved in the biotransformation mechanism of AuCl4 into gold nanoparticles (AuNPs). In this research, we thus focused on studying the effect of Au on growth and nanoparticles formation by analyses of transcriptome, proteome and ionome shift in Arabidopsis. Au exposure favored the growth of Arabidopsis seedling and induced formation of nanoparticles in root and shoot, as indicated by optical and hyperspectral imaging. Root transcriptome analysis demonstrated the differential expression of the members of WRKY, MYB and BHLH gene families, which are involved in the Fe and other essential metals homeostasis. The proteome analysis revealed that Glutathione S-transferases were induced in the shoot and suggested its potential role in the biosynthesis AuNPs. This study also demonstrated the role of plant hormone auxin in determining the Au induced root system architecture. This is the first study using an integrated approach to understand the in planta biotransformation of KAuCl4 into AuNPs

Advances in Cancer Therapeutics: Conventional Thermal Therapy to Nanotechnology-Based Photothermal Therapy

In this review, advancement in cancer therapy that shows a transition from conventional thermal therapies to laser-based photothermal therapies is discussed. Laser-based photothermal therapies are gaining popularity in cancer therapeutics due to their overall outcomes. In photothermal therapy, light is converted into heat to destruct the various types of cancerous growth. The role of nanoparticles as a photothermal agent is emphasized in this review article. Magnetic, as well as non-magnetic, nanoparticles have been effectively used in the photothermal-based cancer therapies. The discussion includes a critical appraisal of in vitro and in vivo, as well as the latest clinical studies completed in this area. Plausible evidence suggests that photothermal therapy is a promising avenue in the treatment of cancer

Interactive Effects of Lead, Copper, Nickel and Zinc on Growth, Metal Uptake and Antioxidative Metabolism of Sesbania drummondii

Sesbania drummondii seedlings were grown in a medium to which lead (Pb), copper (Cu), nickel (Ni) and zinc (Zn) were added singly and in combinations in order to assess the effects of metal interactions on seedling growth, metal accumulation and anti-oxidative system. S. drummondii growth was significantly inhibited with metal treatments. S. drummondii accumulated substantially higher concentrations of metals in the roots than shoots. The uptake of metals followed the order Pb \u3e Cu \u3e Zn \u3e Ni in roots and Pb \u3e Zn \u3e Cu \u3e Ni in shoots. In addition, uptake of a single metal by S. drummondii was affected by the presence of a second metal, suggesting an antagonistic effect or competition between metals at the plant uptake site. A significant increase in both enzymatic [superoxide dismutase (SOD), ascorbate peroxidase (APX), glutathione reductase (GR)] and non-enzymatic (glutathione) antioxidant was observed in the S. drummondii seedlings exposed to different metal treatments. The enhancement in enzyme activities followed the order of Cu \u3e Ni \u3e Pb \u3e Zn. However, compared to the effect of individual metal, metals in combination increased the enzyme activities to varying degrees

Remediation of acid mine drainage-impacted water by vetiver grass (Chrysopogon zizanioides): A multiscale long-term study

Acid mine drainage (AMD) is an acidic discharge from mining sites that contains elevated levels of metals and sulfate (SO42−). AMD can inflict health and environmental dangers through metal toxicity and physical stress. Current methods for AMD treatment, including chemical or passive biological treatments, are often non-sustainable owing to expense, require continuous maintenance, or are unsuitable for prolonged treatment. Our ultimate goal is to develop a cost efficient and sustainable floating treatment wetland system using vetiver grass (Chrysopogon zizanioides). Year-long large- and small-scale hydroponic experiments were used to determine the effectiveness of vetiver for treating AMD-impacted waters from the Tab-Simco mine site in southern Illinois. For the large-scale mesocosmic study, vetiver rafts were suspended in 100-gallon containers. Water quality was monitored by chemical analysis of samples every 28 days and at the end of the experiment (364 days); plant health was monitored by measuring changes in biomass and recording visual changes in root and shoot coloration and morphology. There was higher net removal of Fe (81%) and Pb (81%) with lower removal of Ni (38%), Zn (35%), SO42− (28%), Mn (27%), Cr (21%), Al (11%) and Cu (8.0%). Metals were mainly localized on the root surface as Fe plaques, whereas Mn and Zn showed greater translocation from root to shoot. Furthermore, toxicity characteristic leaching procedure showed that vetiver biomass was not hazardous waste as a result of metal accumulation. From the small-scale experiment, there was near complete removal of SO42− (91%) and metals (90–100%) with the exception of Pb (15%) and Cu (0.0%). These experiments demonstrate that vetiver can effectively remediate AMD-impacted waters over an extended period of time