15
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      From Laboratory to Field: OsNRAMP5-Knockdown Rice Is a Promising Candidate for Cd Phytoremediation in Paddy Fields

      research-article

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Previously, we reported that OsNRAMP5 functions as a manganese, iron, and cadmium (Cd) transporter. The shoot Cd content in OsNRAMP5 RNAi plants was higher than that in wild-type (WT) plants, whereas the total Cd content (roots plus shoots) was lower. For efficient Cd phytoremediation, we produced OsNRAMP5 RNAi plants using the natural high Cd-accumulating cultivar Anjana Dhan (A5i). Using a positron-emitting tracer imaging system, we assessed the time-course of Cd absorption and accumulation in A5i plants. Enhanced 107Cd translocation from the roots to the shoots was observed in A5i plants. To evaluate the phytoremediation capability of A5i plants, we performed a field experiment in a Cd-contaminated paddy field. The biomass of the A5i plants was unchanged by the suppression of OsNRAMP5 expression; the A5i plants accumulated twice as much Cd in their shoots as WT plants. Thus, A5i plants could be used for rapid Cd extraction and the efficient phytoremediation of Cd from paddy fields, leading to safer food production.

          Related collections

          Most cited references35

          • Record: found
          • Abstract: found
          • Article: not found

          Nramp5 is a major transporter responsible for manganese and cadmium uptake in rice.

          Paddy rice (Oryza sativa) is able to accumulate high concentrations of Mn without showing toxicity; however, the molecular mechanisms underlying Mn uptake are unknown. Here, we report that a member of the Nramp (for the Natural Resistance-Associated Macrophage Protein) family, Nramp5, is involved in Mn uptake and subsequently the accumulation of high concentrations of Mn in rice. Nramp5 was constitutively expressed in the roots and encodes a plasma membrane-localized protein. Nramp5 was polarly localized at the distal side of both exodermis and endodermis cells. Knockout of Nramp5 resulted in a significant reduction in growth and grain yield, especially when grown at low Mn concentrations. This growth reduction could be partially rescued by supplying high concentrations of Mn but not by the addition of Fe. Mineral analysis showed that the concentration of Mn and Cd in both the roots and shoots was lower in the knockout line than in wild-type rice. A short-term uptake experiment revealed that the knockout line lost the ability to take up Mn and Cd. Taken together, Nramp5 is a major transporter of Mn and Cd and is responsible for the transport of Mn and Cd from the external solution to root cells.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Rice plants take up iron as an Fe3+-phytosiderophore and as Fe2+.

            Only graminaceous monocots possess the Strategy II iron (Fe)-uptake system in which Fe is absorbed by roots as an Fe3+-phytosiderophore. In spite of being a Strategy II plant, however, rice (Oryza sativa) contains the previously identified Fe2+ transporter OsIRT1. In this study, we isolated the OsIRT2 gene from rice, which is highly homologous to OsIRT1. Real-time PCR analysis revealed that OsIRT1 and OsIRT2 are expressed predominantly in roots, and these transporters are induced by low-Fe conditions. When expressed in yeast (Saccharomyces cerevisiae) cells, OsIRT2 cDNA reversed the growth defects of a yeast Fe-uptake mutant. This was similar to the effect of OsIRT1 cDNA. OsIRT1- and OsIRT2-green fluorescent protein fusion proteins localized to the plasma membrane when transiently expressed in onion (Allium cepa L.) epidermal cells. OsIRT1 promoter-GUS analysis revealed that OsIRT1 is expressed in the epidermis and exodermis of the elongating zone and in the inner layer of the cortex of the mature zone of Fe-deficient roots. OsIRT1 expression was also detected in the ccompanion cells. Analysis using the positron-emitting tracer imaging system showed that rice plants are able to take up both an Fe3+-phytosiderophore and Fe2+. This result indicates that, in addition to absorbing an Fe3+-phytosiderophore, rice possesses a novel Fe-uptake system that directly absorbs the Fe2+, a strategy that is advantageous for growth in submerged conditions.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Mobilization of vacuolar iron by AtNRAMP3 and AtNRAMP4 is essential for seed germination on low iron.

              Iron (Fe) is necessary for all living cells, but its bioavailability is often limited. Fe deficiency limits agriculture in many areas and affects over a billion human beings worldwide. In mammals, NRAMP2/DMT1/DCT1 was identified as a major pathway for Fe acquisition and recycling. In plants, AtNRAMP3 and AtNRAMP4 are induced under Fe deficiency. The similitude of AtNRAMP3 and AtNRAMP4 expression patterns and their common targeting to the vacuole, together with the lack of obvious phenotype in nramp3-1 and nramp4-1 single knockout mutants, suggested a functional redundancy. Indeed, the germination of nramp3 nramp4 double mutants is arrested under low Fe nutrition and fully rescued by high Fe supply. Mutant seeds have wild type Fe content, but fail to retrieve Fe from the vacuolar globoids. Our work thus identifies for the first time the vacuole as an essential compartment for Fe storage in seeds. Our data indicate that mobilization of vacuolar Fe stores by AtNRAMP3 and AtNRAMP4 is crucial to support Arabidopsis early development until efficient systems for Fe acquisition from the soil take over.
                Bookmark

                Author and article information

                Contributors
                Role: Editor
                Journal
                PLoS One
                PLoS ONE
                plos
                plosone
                PLoS ONE
                Public Library of Science (San Francisco, USA )
                1932-6203
                2014
                5 June 2014
                : 9
                : 6
                : e98816
                Affiliations
                [1 ]Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
                [2 ]Graduate School of Science, Tohoku University, Aoba-ku, Sendai, Miyagi, Japan
                [3 ]Agrogenomics Research Center, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan
                [4 ]Quantum Beam Science Directorate, Japan Atomic Energy Agency, Takasaki, Gunma, Japan
                [5 ]Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, Nonoichi-shi, Ishikawa, Japan
                Universidade Federal do Rio Grande do Sul, Brazil
                Author notes

                Competing Interests: Mr. H. Suto (Tokyo Nuclear Services Co., Ltd., Tsukuba, Japan) provided technical assistance in producing 107Cd by irradiation. There are no patents, products in development or marketed products to declare. This does not alter the authors’ adherence to all the PLOS ONE policies on sharing data and materials.

                Conceived and designed the experiments: YI NKN HN. Performed the experiments: RT YI HS TS NS NK SI Y-GY SF HN. Analyzed the data: RT YI KB NKN HN. Contributed reagents/materials/analysis tools: KS KO MY. Wrote the paper: RT KB NKN HN.

                Article
                PONE-D-14-02830
                10.1371/journal.pone.0098816
                4047016
                24901230
                281db034-813a-40ed-8237-aeb337997622
                Copyright @ 2014

                This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

                History
                : 22 January 2014
                : 6 May 2014
                Page count
                Pages: 7
                Funding
                This study was supported by the Program for Promotion of Basic Research Activities for Innovative Biosciences and by a grant from the Ministry of Agriculture, Forestry, and Fisheries of Japan (Genomics for Agricultural Innovation, GMB0001). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
                Categories
                Research Article
                Biology and Life Sciences
                Agriculture
                Agricultural Biotechnology
                Genetically Modified Organisms
                Transgenic Plants
                Crops
                Cereal Crops
                Rice
                Biotechnology
                Applied Microbiology
                Bioremediation
                Environmental Biotechnology
                Plant Biotechnology
                Plant Science
                Toxicology
                Toxic Agents
                Toxins
                Heavy Metals
                Physical Sciences
                Chemistry
                Environmental Chemistry
                Pollutants

                Uncategorized
                Uncategorized

                Comments

                Comment on this article