Phytostabilization of copper mine tailings with biosolids: implications for metal uptake and productivity of Lolium perenne.

A greenhouse pot experiment was conducted to evaluate the feasibility of using biosolids and Lolium perenne for the phytostabilization of copper mine tailings and to evaluate the patterns of metal accumulation and translocation in plants. Biosolids were applied either on the surface or mixed with the tailings at rates of 0, 6, and 12% w/w. All pots were seeded with L. perenne and after six months, the plants were harvested and separated into roots and shoots for metal concentrations analyses as well as some physiological characteristics of the plants. In order to correlate the metal content in plant tissues with some chemical properties, the pore-water of the substrates was analyzed for metals, pH and dissolved organic carbon. Results showed that biosolids application increased the dry biomass production of L. perenne and the shoot concentrations of N and chlorophyll. On the other hand, biosolids increased the concentration of Cu and Zn in the pore-water and in plant tissues. Despite this, there were no evident symptoms of phytotoxicity and the concentration of metals was within the normal ranges described for plants and below the maximum tolerable level for animals. In addition, plant tissue analysis showed that the application of biosolids could significantly reduce Mo uptake and shoot accumulation in plants. The metals were taken up by plants in the following order: Cu>Zn>Mo>Cd. The distribution patterns of metals in plants showed that metals were mainly accumulated in the roots and only a small amount of them were transported to the shoots. These results suggest that mixed application of biosolids (6%) and the use of L. perenne could be appropriate for use in programs of phytostabilization of copper mine tailings. However, these results should be tested under field conditions in order to confirm their efficacy under semi-arid Mediterranean climate conditions.

Omics Approaches for Understanding Grapevine Berry Development: Regulatory Networks Associated with Endogenous Processes and Environmental Responses.

Grapevine fruit development is a dynamic process that can be divided into three stages: formation (I), lag (II), and ripening (III), in which physiological and biochemical changes occur, leading to cell differentiation and accumulation of different solutes. These stages can be positively or negatively affected by multiple environmental factors. During the last decade, efforts have been made to understand berry development from a global perspective. Special attention has been paid to transcriptional and metabolic networks associated with the control of grape berry development, and how external factors affect the ripening process. In this review, we focus on the integration of global approaches, including proteomics, metabolomics, and especially transcriptomics, to understand grape berry development. Several aspects will be considered, including seed development and the production of seedless fruits; veraison, at which anthocyanin accumulation begins in the berry skin of colored varieties; and hormonal regulation of berry development and signaling throughout ripening, focusing on the transcriptional regulation of hormone receptors, protein kinases, and genes related to secondary messenger sensing. Finally, berry responses to different environmental factors, including abiotic (temperature, water-related stress and UV-B radiation) and biotic (fungi and viruses) stresses, and how they can significantly modify both, development and composition of vine fruit, will be discussed. Until now, advances have been made due to the application of Omics tools at different molecular levels. However, the potential of these technologies should not be limited to the study of single-level questions; instead, data obtained by these platforms should be integrated to unravel the molecular aspects of grapevine development. Therefore, the current challenge is the generation of new tools that integrate large-scale data to assess new questions in this field, and to support agronomical practices.

Efficacy of lime, biosolids, and mycorrhiza for the phytostabilization of sulfidic copper tailings in Chile: a greenhouse experiment.

Inadequate abandonment of copper mine tailings under semiarid Mediterranean climate type conditions has posed important environmental risks in Chile due to wind and rain erosion. There are cost-effective technologies for tailings stabilization such as phytostabilization. However, this technology has not been used in Chile yet. This study evaluated in a greenhouse assay the efficacy of biosolids, lime, and a commercial mycorrhiza to improve adverse conditions of oxidized Cu mine tailings for adequate establishment and grow of Lolium perenne L. var nui. Chemical characterization of experimental substrates and pore water samples were performed; plant density, biomass production, chlorophyll content, and metal content in shoots was evaluated in rye grass plants after an eight-week growth period. Results showed that neutralization of tailings and superficial application of biosolids increased both aerial biomass production and chlorophyll content of rye grass. Increased Cu solubilization and translocation to shoots occurred after biosolids application (mixed), particularly on unlimed tailings, due to formation of soluble organometallic complexes with dissolved organic carbon (DOC) which can be readily absorbed by plant roots. Positive effects of mycorrhizal inoculation on rye grass growth were restricted to treatments with superficial application of biosolids, probably due to Cu toxicity effects on commercial mycorrhiza used (Glomulus intraradices).

Simultaneous determination of parathion and p-nitrophenol in vegetable tissues by derivative spectrophotometry.

A first derivative spectrophotometric method has been developed for the determination of parathion and p-nitrophenol in vegetable tissues. Ethanol was used as solvent for extracting the compounds from the tissues and subsequently the samples were evaluated against a vegetable tissue blank, directly by derivative spectrophotometry. The simultaneous determination of these compounds can be carried out using the zero-crossing approach for parathion at 253.0 nm and for p-nitrophenol at 273.1 nm. In the samples each analyte was determined in the presence of one another in the ranges between 4.9 to 3883.5 microg g(-1) for parathion and 4.9 to 3285.3 microg g(-1) for p-nitrophenol. The detection limits (3a) were found to be 1.5 and 1.4 microg g(-1) for parathion and p-nitrophenol, respectively. The relative standard deviations were in all instances less than 1.8%. The proposed method was applied to the determination of the analytes in spiked leaves of corn. The results show a good recovery and they are in agreement with those obtained by polarography.