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ADVERTISEMENT RETURN TO ISSUEPREVCorrespondence/Rebut...Correspondence/RebuttalNEXTResponse to the Comment by Van Geen and DuxburyF. J. Zhao, S. P. McGrath, and A. A. MehargView Author Information Soil Science Department, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, U.K. School of Biological Sciences, University of Aberdeen, Cruickshank Building, St. Machar Drive, Aberdeen, AB24 3UU, U.K.Cite this: Environ. Sci. Technol. 2009, 43, 10, 3972–3973Publication Date (Web):April 3, 2009Publication History Received4 March 2009Published online3 April 2009Published inissue 15 May 2009https://pubs.acs.org/doi/10.1021/es900679uhttps://doi.org/10.1021/es900679uarticle-commentaryACS PublicationsCopyright © 2009 American Chemical Society. This publication is available under these Terms of Use. Request reuse permissions This publication is free to access through this site. Learn MoreArticle Views680Altmetric-Citations2LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail PDF (56 KB) Get e-AlertscloseSUBJECTS:Environmental science,Genetics,Grain,Plant derived food,Soils Get e-Alerts
Tea is a major dietary source of aluminium (Al) to humans. There is a need to understand how environmental factors influence Al accumulation in tea leaves
Deficiency of sulphur (S) has been recognised as a limiting factor for crop production in many regions in the world. In particular, incidence of S deficiency has increasingly been reported in Brassica and cereal crops in Western Europe over the last decade, mainly as a consequence of a massive decrease of atmospheric S inputs. The S requirement of wheat is about 15–20 kg/ha for optimum growth. Reproductive growth of wheat appears to be more sensitive to S deficiency than vegetative growth, with decreased grain size under S-limiting conditions. In addition to the effects on yields, the S status of wheat grain is an important parameter for the quality of wheat products. Limiting S availability has been shown to favour the synthesis and accumulation of S-poor or low-S storage proteins such as ω-gliadin and high molecular weight (HMW) subunits of glutenin at the expense of S-rich proteins. Sulphur deficiency also decreases the proportion of polymeric proteins in total proteins, but shifts the distribution of polymeric proteins toward lower molecular weight. These changes in protein composition are associated with alterations of dough rheology. Significant responses of breadmaking quality to the addition of S fertilisers have been established under field conditions. Recent studies have also shown that breadmaking quality correlated more closely with grain S concentration than with N concentration. Recent progress in cloning genes encoding components involved in sulphate uptake and assimilation has substantially increased our understanding of plant S nutrition and its regulation, and opened up opportunities for manipulation of S uptake and metabolism in plants.
Insufficient iron (Fe) is one of the most prevalent micronutrient deficiencies in humans, with billions of people affected. Cereal grains are an important source of Fe for humans but the bioavailability of Fe in cereals is generally low. Information regarding the cellular and sub-cellular localisation of Fe in wheat grain will aid optimising nutrient delivery for human health. In this study high resolution secondary ion mass spectrometry (NanoSIMS) was used to map the distribution of Fe in the aleurone layer and in the endosperm of immature wheat grain. Iron was shown to be localised strongly in the phytin globoids in the aleurone cells and to a lesser extent in the cytoplasm around the starch granules in the endosperm.
The bulk of this book is devoted to the arsenic biogeochemical cycles in the paddy rice systems, the mechanisms of arsenic uptake and accumulation by rice plants, dietary arsenic intake from rice and potential mitigation methods to reduce arsenic accumulation in...
Selenium (Se) intake has decreased substantially in the UK population since 1970s. To investigate whether Se concentration in wheat grain has changed as a result of yield improvement or environmental changes, we analyzed archived wheat grain from the Broadbalk Wheat Experiment at Rothamsted, England, which has been run continuously for over 160 years. Wheat grain and soil samples were selected from plots receiving different fertilizer or manure treatments. Grain Se concentration varied from 11 to 236 ng g−1, with a mean and median of 44 and 32 ng g−1, respectively. Grain samples from the unfertilized control plot had significantly higher concentrations of Se than those from fertilized or manured plots; the latter received various amounts of S and also had higher grain yield. No significant trends in grain Se concentrations were detected in the fertilized or manured plots, in spite of a dramatic increase in grain yield since the introduction of modern short-straw cultivars in the mid 1960s. In the control plot, grain samples had higher Se concentrations in the periods before 1920 or after 1970 than those during 1920–1970. This temporal pattern mirrored that of SO2 emissions and atmospheric S deposition. Soil Se concentrations showed an increasing trend in all plots over 160 years. The results show that the Se concentration of wheat grain from the Broadbalk experiment was influenced by S inputs from fertilizers and atmospheric deposition, and that improving grain yield through plant breeding has not resulted in a significant decrease in grain Se concentration in the fertilized plots.
*When supplied with arsenate (As(V)), plant roots extrude a substantial amount of arsenite (As(III)) to the external medium through as yet unidentified pathways. The rice (Oryza sativa) silicon transporter Lsi1 (OsNIP2;1, an aquaporin channel) is the major entry route of arsenite into rice roots. Whether Lsi1 also mediates arsenite efflux was investigated. *Expression of Lsi1 in Xenopus laevis oocytes enhanced arsenite efflux, indicating that Lsi1 facilitates arsenite transport bidirectionally. *Arsenite was the predominant arsenic species in arsenate-exposed rice plants. During 24-h exposure to 5 mum arsenate, rice roots extruded arsenite to the external medium rapidly, accounting for 60-90% of the arsenate uptake. A rice mutant defective in Lsi1 (lsi1) extruded significantly less arsenite than the wild-type rice and, as a result, accumulated more arsenite in the roots. By contrast, Lsi2 mutation had little effect on arsenite efflux to the external medium. *We conclude that Lsi1 plays a role in arsenite efflux in rice roots exposed to arsenate. However, this pathway accounts for only 15-20% of the total efflux, suggesting the existence of other efflux transporters.
The first solid food that most humans eat as weaning babies is rice, because of its blandness, lack of allergen reactions and material properties that give rise to a palatable porridge (Meharg et al. 2008). It is also the dietary staple for half the world’s...
The agronomic application of nanotechnology in plants (phytonanotechnology) has the potential to alter conventional plant production systems, allowing for the controlled release of agrochemicals (e.g., fertilizers, pesticides, and herbicides) and target-specific delivery of biomolecules (e.g., nucleotides, proteins, and activators). An improved understanding of the interactions between nanoparticles (NPs) and plant responses, including their uptake, localization, and activity, could revolutionize crop production through increased disease resistance, nutrient utilization, and crop yield. Herewith, we review potential applications of phytonanotechnology and the key processes involved in the delivery of NPs to plants. To ensure both the safe use and social acceptance of phytonanotechnology, the adverse effects, including the risks associated with the transfer of NPs through the food chain, are discussed.
A pot experiment was conducted to compare two strategies of phytoremediation: natural phytoextraction using the Zn and Cd hyperaccumulator Thlaspi caerulescens J. Presl & C. Presl versus chemically enhanced phytoextraction using maize (Zea mays L.) treated with ethylenediaminetetraacetic acid (EDTA). The study used an industrially contaminated soil and an agricultural soil contaminated with metals from sewage sludge. Three crops of T. caerulescens grown over 391 d removed more than 8 mg kg(-1) Cd and 200 mg kg(-1) Zn from the industrially contaminated soil, representing 43 and 7% of the two metals in the soil. In contrast, the high concentration of Cu in the agricultural soil severely reduced the growth of T. caerulescens, thus limiting its phytoextraction potential. The EDTA treatment greatly increased the solubility of heavy metals in both soils, but this did not result in a large increase in metal concentrations in the maize shoots. Phytoextraction of Cd and Zn by maize + EDTA was much smaller than that by T. caerulescens from the industrially contaminated soil, and was either smaller (Cd) or similar (Zn) from the agricultural soil. After EDTA treatment, soluble heavy metals in soil pore water occurred mainly as metal-EDTA complexes, which were persistent for several weeks. High concentrations of heavy metals in soil pore water after EDTA treatment could pose an environmental risk in the form of ground water contamination.
