Publications by authors named "Naoko Ohkama-Ohtsu"

43 Publications

Influence of potassium-solubilizing bacteria on the growth and radiocesium phyto-transfer of Brassica rapa L. var. perviridis grown in contaminated Fukushima soils.

J Environ Radioact 2021 Jun 17;237:106682. Epub 2021 Jun 17.

Institute of Agriculture, Tokyo University of Agriculture and Technology, Saiwaicho 3-5-8, Fuchu, Tokyo, 183-12 8509, Japan; The Faculty of Food and Agricultural Science, Fukushima University, Kanayagawa, Fukushima City, Fukushima, 960-1296, Japan.

The supply of K, being the chemical analog of Cs, affects the phytotransfer of radiocesium such as Cs from contaminated soils and its accumulation in plant tissues. Since K and Cs have high affinity to the same clay particle surfaces, the presence of potassium-solubilizing bacteria (KSB) could increase the availability of not only K in the rhizosphere but also of radiocesium. In this study, we obtained five KSB isolates with the highest solubilization capacities from soybean rhizosphere on modified Aleksandrov medium containing sericite as K source. Based on biochemical and 16S rRNA gene sequence analysis, we identified the bacteria as Bacillus aryabhattai MG774424, Pseudomonas umsongensis MG774425, P. frederiksbergensis MG774426, Burkholderia sabiae MG774427, and P. mandelii MG774428. We evaluated the KSB isolates based on plant growth promotion and Cs accumulation in komatsuna (Brassica rapa L. var. Perviridis) grown in three soils collected from Miyanoiri, Takanishi, and Ota contaminated by Cs from the Fukushima accident. Inoculation with KSB showed beneficial effects on plant growth and increased the overall plant biomass production (~40%). On the average, KSB inoculation resulted in the removal of 0.07 ± 0.04% of Cs from the soil, more than twice the control. But similar to the effect of KSB inoculation on komatsuna biomass production, different KSBs performed variably and exhibited site-specific responses independent of their K-solubilizing capacities, with higher Cs phyto-transfer in roots than in shoots. In terms of root transfer factor (TF), values were highest in komatsuna plants grown in Miyanoiri and Ota soils inoculated with P. frederiksbergensis and Burkholderia sabiae, while they were highest in Takanishi soils inoculated with Bacillus aryabhattai and P. umsongensis. These TF values were also much higher than previously reported values for komatsuna grown in Cs-contaminated Fukushima soils inoculated with other rhizobacteria. Thus, KSB inoculation significantly enhance not only the growth of komatsuna but Cs uptake.
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http://dx.doi.org/10.1016/j.jenvrad.2021.106682DOI Listing
June 2021

Genetic Diversity and Characterization of Symbiotic Bacteria Isolated from Endemic Phaseolus Cultivars Located in Contrasting Agroecosystems in Venezuela.

Microbes Environ 2021 ;36(2)

Institute of Agriculture, Tokyo University of Agriculture and Technology (TUAT).

Phaseolus vulgaris is a grain cultivated in vast areas of different countries. It is an excellent alternative to the other legumes in the Venezuelan diet and is of great agronomic interest due to its resistance to soil acidity, drought, and high temperatures. Phaseolus establishes symbiosis primarily with Rhizobium and Ensifer species in most countries, and this rhizobia-legume interaction has been studied in Asia, Africa, and the Americas. However, there is currently no evidence to show that rhizobia nodulate the endemic cultivars of P. vulgaris in Venezuela. Therefore, we herein investigated the phylogenetic diversity of plant growth-promoting and N-fixing nodulating bacteria isolated from the root nodules of P. vulgaris cultivars in a different agroecosystem in Venezuela. In comparisons with other countries, higher diversity was found in isolates from P. vulgaris nodules, ranging from α- and β-proteobacteria. Some isolates belonging to several new phylogenetic lineages within Bradyrhizobium, Ensifer, and Mesorhizobium species were also specifically isolated at some topographical regions. Additionally, some isolates exhibited tolerance to high temperature, acidity, alkaline pH, salinity stress, and high Al levels; some of these characteristics may be related to the origin of the isolates. Some isolates showed high tolerance to Al toxicity as well as strong plant growth-promoting and antifungal activities, thereby providing a promising agricultural resource for inoculating crops.
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http://dx.doi.org/10.1264/jsme2.ME20157DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8209454PMC
January 2021

Retrograde sulfur flow from glucosinolates to cysteine in .

Proc Natl Acad Sci U S A 2021 Jun;118(22)

Metabolic Systems Research Team, RIKEN Center for Sustainable Resource Science, Yokohama 230-0045, Japan;

Specialized (secondary) metabolic pathways in plants have long been considered one-way routes of leading primary metabolite precursors to bioactive end products. Conversely, endogenous degradation of such "end" products in plant tissues has been observed following environmental stimuli, including nutrition stress. Therefore, it is of general interest whether specialized metabolites can be reintegrated into primary metabolism to recover the invested resources, especially in the case of nitrogen- or sulfur-rich compounds. Here, we demonstrate that endogenous glucosinolates (GLs), a class of sulfur-rich plant metabolites, are exploited as a sulfur source by the reallocation of sulfur atoms to primary metabolites such as cysteine in Tracer experiments using S- or deuterium-labeled GLs depicted the catabolic processing of GL breakdown products in which sulfur is mobilized from the thioglucoside group in GL molecules, potentially accompanied by the release of the sulfate group. Moreover, we reveal that beta-glucosidases BGLU28 and BGLU30 are the major myrosinases that initiate sulfur reallocation by hydrolyzing particular GL species, conferring sulfur deficiency tolerance in , especially during early development. The results delineate the physiological function of GL as a sulfur reservoir, in addition to their well-known functions as defense chemicals. Overall, our findings demonstrate the bidirectional interaction between primary and specialized metabolism, which enhances our understanding of the underlying metabolic mechanisms via which plants adapt to their environments.
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http://dx.doi.org/10.1073/pnas.2017890118DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8179156PMC
June 2021

Shoot base responds to root-applied glutathione and functions as a critical region to inhibit cadmium translocation from the roots to shoots in oilseed rape (Brassica napus).

Plant Sci 2021 Apr 24;305:110822. Epub 2021 Jan 24.

Department of Biological Production, Faculty of Bioresource Sciences, Akita Prefectural University, 241-438 Kaidobata-Nishi, Shimoshinjo-Nakano, Akita-shi, Akita, 010-0195, Japan; Department of Bioscience, Faculty of Life Sciences, Tokyo University of Agriculture, 1-1-1 Sakuragaoka Setagaya-ku, Tokyo, 156-8502, Japan. Electronic address:

Glutathione (GSH) is a tripeptide involved in controlling heavy metal movement in plants. Our previous study showed that GSH, when site-specifically applied to plant roots, inhibits Cd translocation from the roots to shoots in hydroponically cultured oilseed rape (Brassica napus) plants. A factor that led to this inhibitory effect was the activation of Cd efflux from root cells. To further investigate the molecular mechanism triggered by root-applied GSH, Cd movement was non-invasively monitored using a positron-emitting tracer imaging system. The Cd absorption and efflux process in the roots were visualized successfully. The effects of GSH on Cd efflux from root cells were estimated by analyzing imaging data. Reanalysis of image data suggested that GSH applied to roots, at the shoot base, activated Cd return. Cutting the shoot base significantly inhibited Cd efflux from root cells. These experimental results demonstrate that the shoot base plays an important role in distributing Cd throughout the plant body. Furthermore, microarray analysis revealed that about 400 genes in the roots responded to root-applied GSH. Among these, there were genes for transporter proteins related to heavy metal movement in plants and proteins involved in the structure modification of cell walls.
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http://dx.doi.org/10.1016/j.plantsci.2021.110822DOI Listing
April 2021

Glutathione and Its Biosynthetic Intermediates Alleviate Cesium Stress in Arabidopsis.

Front Plant Sci 2019 21;10:1711. Epub 2020 Jan 21.

RIKEN Center for Sustainable Resource Science, Yokohama, Japan.

Phytoremediation is optimized when plants grow vigorously while accumulating the contaminant of interest. Here we show that sulphur supply alleviates aerial chlorosis and growth retardation caused by cesium stress without reducing cesium accumulation in . This alleviation was not due to recovery of cesium-induced potassium decrease in plant tissues. Sulphur supply also alleviated sodium stress but not potassium deficiency stress. Cesium-induced root growth inhibition has previously been demonstrated as being mediated through jasmonate biosynthesis and signalling but it was found that sulphur supply did not decrease the levels of jasmonate accumulation or jasmonate-responsive transcripts. Instead, induction of a glutathione synthetase gene and reduction of a phytochelatin synthase gene as well as increased accumulation of glutathione and cysteine were observed in response to cesium. Exogenous application of glutathione or concomitant treatments of its biosynthetic intermediates indeed alleviated cesium stress. Interestingly, concomitant treatments of glutathione biosynthetic intermediates together with a glutathione biosynthesis inhibitor did not cancel the alleviatory effects against cesium suggesting the existence of a glutathione-independent pathway. Taken together, our findings demonstrate that plants exposed to cesium increase glutathione accumulation to alleviate the deleterious effects of cesium and that exogenous application of sulphur-containing compounds promotes this innate process.
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http://dx.doi.org/10.3389/fpls.2019.01711DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6985154PMC
January 2020

SLIM1 Transcription Factor Promotes Sulfate Uptake and Distribution to Shoot, Along with Phytochelatin Accumulation, Under Cadmium Stress in Arabidopsis thaliana.

Plants (Basel) 2020 Jan 29;9(2). Epub 2020 Jan 29.

Department of Bioscience and Biotechnology, Graduate School of Bioresource and Bioenvironmental Sciences, Faculty of Agriculture, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.

Sulfur (S) assimilation, which is initiated by sulfate uptake, generates cysteine, the substrate for glutathione (GSH) and phytochelatin (PC) synthesis. GSH and PC contribute to cadmium (Cd) detoxification by capturing it for sequestration. Although Cd exposure is known to induce the expression of S-assimilating enzyme genes, including sulfate transporters (SULTRs), mechanisms of their transcriptional regulation are not well understood. Transcription factor SLIM1 controls transcriptional changes during S deficiency (-S) in Arabidopsis thaliana. We examined the potential involvement of SLIM1 in inducing the S assimilation pathway and PC accumulation. Cd treatment reduced the shoot fresh weight in the sulfur limitation1 (slim1) mutant but not in the parental line (1;2PGN). Cd-induced increases of sulfate uptake and SULTR1;2 expressions were diminished in the slim1 mutant, suggesting that SLIM1 is involved in inducing sulfate uptake during Cd exposure. The GSH and PC levels were lower in slim1 than in the parental line, indicating that SLIM1 was required for increasing PC during Cd treatment. Hence, SLIM1 indirectly contributes to Cd tolerance of plants by inducing -S responses in the cell caused by depleting the GSH pool, which is consumed by enhanced PC synthesis and sequestration to the vacuole.
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http://dx.doi.org/10.3390/plants9020163DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7076661PMC
January 2020

Characterization of Rhizobia for the Improvement of Soybean Cultivation at Cold Conditions in Central Europe.

Microbes Environ 2020 ;35(1)

Institute of Global Innovation Research (GIR), Tokyo University of Agriculture and Technology.

In central Europe, soybean cultivation is gaining increasing importance to reduce protein imports from overseas and make cropping systems more sustainable. In the field, despite the inoculation of soybean with commercial rhizobia, its nodulation is low. In many parts of Europe, limited information is currently available on the genetic diversity of rhizobia and, thus, biological resources for selecting high nitrogen-fixing rhizobia are inadequate. These resources are urgently needed to improve soybean production in central Europe. The objective of the present study was to identify strains that have the potential to increase nitrogen fixation by and the yield of soybean in German soils. We isolated and characterized 77 soybean rhizobia from 18 different sampling sites. Based on a multilocus sequence analysis (MLSA), 71% of isolates were identified as Bradyrhizobium and 29% as Rhizobium. A comparative analysis of the nodD and nifH genes showed no significant differences, which indicated that the soybean rhizobia symbiotic genes in the present study belong to only one type. One isolate, GMF14 which was tolerant of a low temperature (4°C), exhibited higher nitrogen fixation in root nodules and a greater plant biomass than USDA 110 under cold conditions. These results strongly suggest that some indigenous rhizobia enhance biological nitrogen fixation and soybean yield due to their adaption to local conditions.
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http://dx.doi.org/10.1264/jsme2.ME19124DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7104276PMC
March 2020

Phylogenetic Analysis of Symbiotic Bacteria Associated with Two Vigna Species under Different Agro-Ecological Conditions in Venezuela.

Microbes Environ 2020 ;35(1)

Institute of Agriculture, Tokyo University of Agriculture and Technology (TUAT).

Vigna is a genus of legumes cultivated in specific areas of tropical countries. Species in this genus are important crops worldwide. Vigna species are of great agronomic interest in Venezuela because Vigna beans are an excellent alternative to other legumes. However, this type of crop has some cultivation issues due to sensitivity to acidic soils, high temperatures, and salinity stress, which are common in Venezuela. Vigna species establish symbioses mainly with Bradyrhizobium and Ensifer, and Vigna-rhizobia interactions have been examined in Asia, Africa, and America. However, the identities of the rhizobia associated with V. radiata and V. unguiculata in Venezuela remain unknown. In the present study, we isolated Venezuelan symbiotic rhizobia associated with Vigna species from soils with contrasting agroecosystems or from fields in Venezuela. Several types of soils were used for bacterial isolation and nodules were sampled from environments characterized by abiotic stressors, such as high temperatures, high concentrations of NaCl, and acidic or alkaline pH. Venezuelan Vigna-rhizobia were mainly fast-growing. Sequencing of several housekeeping genes showed that in contrast to other continents, Venezuelan Vigna species were nodulated by rhizobia genus including Burkholderia, containing bacteria from several new phylogenetic lineages within the genus Bradyrhizobium. Some Rhizobium and Bradyrhizobium isolates were tolerant of high salinity and Al toxicity. The stress tolerance of strains was dependent on the type of rhizobia, soil origin, and cultivation history. An isolate classified as R. phaseoli showed the highest plant biomass, nitrogen fixation, and excellent abiotic stress response, suggesting a novel promising inoculant for Vigna cultivation in Venezuela.
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http://dx.doi.org/10.1264/jsme2.ME19120DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7104274PMC
January 2020

Effects of enhancing endogenous and exogenous glutathione in roots on cadmium movement in Arabidopsis thaliana.

Plant Sci 2020 Jan 21;290:110304. Epub 2019 Oct 21.

Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, 3-5-8, Saiwai-cho, Fuchu-shi, Tokyo, 183-8509, Japan; Institute of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8, Saiwai-cho, Fuchu-shi, Tokyo, 183-8509, Japan.

Glutathione (GSH) is a thiol-containing compound involved in many aspects of plant metabolism. In the present study, we investigated how enhancing endogenous and exogenous GSH affects cadmium (Cd) movement and distribution in Arabidopsis plants cultured hydroponically. Transgenic Arabidopsis plants with a strong ability to synthesize GSH in roots were generated by transforming the gene encoding the bifunctional γ-glutamylcysteine synthetase-glutathione synthetase enzyme from Streptococcus thermophiles (StGCS-GS). Enhancing endogenous and exogenous GSH decreased the Cd translocation ratio in different ways. Only exogenous GSH significantly inhibited Cd translocation from roots to shoots in wild-type and transgenic Arabidopsis plants. Our study demonstrated that GSH mainly functions outside root cells to inhibit Cd translocation from roots to shoots.
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http://dx.doi.org/10.1016/j.plantsci.2019.110304DOI Listing
January 2020

Isolation and Screening of Indigenous Plant Growth-promoting Rhizobacteria from Different Rice Cultivars in Afghanistan Soils.

Microbes Environ 2019 Dec 14;34(4):347-355. Epub 2019 Sep 14.

Institute of Agriculture, Tokyo University of Agriculture and Technology.

To develop biofertilizers for rice in Afghanistan, 98 plant growth-promoting rhizobacteria were isolated from rice plants and their morphological and physiological characteristics, such as indole-3-acetic acid production, acetylene reduction, phosphate and potassium solubilization, and siderophore production, were evaluated. The genetic diversity of these bacteria was also analyzed based on 16S rRNA gene sequences. Of 98 bacteria, 89.7% produced IAA, 54.0% exhibited nitrogenase activity, and 40% showed phosphate solubilization and siderophore production. Some isolates assigned to Pseudomonas (brassicacearum, chengduensis, plecoglossicida, resinovorans, and straminea) formed a relationship with rice, and P. resinovorans and P. straminea showed nitrogen fixation. Rhizobium borbori and R. rosettiformans showed a relationship with rice plants and nitrogen fixation. Among the isolates examined, AF134 and AF137 belonging to Enterobacter ludwigii and P. putida produced large amounts of IAA (92.3 μg mL) and exhibited high nitrogenase activity (647.4 nmol CH h), respectively. In the plant growth test, more than 70% of the inoculated isolates showed significantly increased root and shoot dry weights. Highly diverse bacterial isolates showing promising rice growth-promoting traits were obtained from Afghanistan alkaline soils.
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http://dx.doi.org/10.1264/jsme2.ME18168DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6934389PMC
December 2019

Phloem-specific overexpression of AtOPT6 in Arabidopsis enhances Zn transport into shoots.

Plant Sci 2019 Aug 30;285:91-98. Epub 2019 Apr 30.

Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, Tokyo, 183-8509, Japan; Institute of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, 183-8509, Japan. Electronic address:

The Arabidopsis oligopeptide transporter AtOPT6 is membrane transport protein that mediated transport of glutathione in both the reduced (GSH) and oxidized (GSSG) forms. In this study, the role of AtOPT6 in glutathione distribution throughout the plant was investigated. We found that transgenic Arabidopsis overexpressing AtOPT6 under the control of a phloem-specific promoter of sucrose-proton symporter 2 (pSUC2), remarkably increased AtOPT6 transcript levels, ranging from 30- to 40-fold in shoots and 6- to 10-fold in roots, relative to the wild type. AtOPT6-overexpressing lines could elevate the foliar glutathione content; however, glutathione content in the phloem did not change. We observed that the ratio of shoot glutathione content to total glutathione content increased in AtOPT6-overexpressing lines, but not in transgenic Arabidopsis with elevated foliar GSH synthesis. These results indicate the possibility that loading and unloading of glutathione in phloem tissues are enhanced in AtOPT6-overexpressing lines under the control of pSUC2. The results of heavy metal analysis revealed that transgenic Arabidopsis overexpressing AtOPT6 under the control of pSUC2 could promote the transport of Zn into shoots as effectively as transgenic Arabidopsis with elevated foliar GSH synthesis, or wild-type plants with exogenous foliar application of GSH.
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http://dx.doi.org/10.1016/j.plantsci.2019.04.022DOI Listing
August 2019

Foliar-applied glutathione activates zinc transport from roots to shoots in oilseed rape.

Plant Sci 2019 Jun 13;283:424-434. Epub 2018 Nov 13.

Institute of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo, 183-8509, Japan.

Glutathione is a tripeptide involved in diverse aspects of plant metabolism. We investigated how the reduced form of glutathione, GSH, applied site-specifically to plants, affects zinc (Zn) distribution and behavior in oilseed rape plants (Brassica napus) cultured hydroponically. Foliar-applied GSH significantly increased the Zn content in shoots and the root-to-shoot Zn translocation ratio; furthermore, this treatment raised the Zn concentration in the cytosol of root cells and substantially enhanced Zn xylem loading. Notably, microarray analysis revealed that the gene encoding pectin methylesterase was upregulated in roots following foliar GSH treatment. We conclude that certain physiological signals triggered in response to foliar-applied GSH were transported via sieve tubes and functioned in root cells, which, in turn, increased Zn availability in roots by releasing Zn from their cell wall. Consequently, root-to-shoot translocation of Zn was activated and Zn accumulation in the shoot was markedly increased.
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http://dx.doi.org/10.1016/j.plantsci.2018.10.018DOI Listing
June 2019

Elevated glutathione synthesis in leaves contributes to zinc transport from roots to shoots in Arabidopsis.

Plant Sci 2019 Jun 13;283:416-423. Epub 2018 Nov 13.

Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan; Institute of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan. Electronic address:

Glutathione (GSH) is a vital compound involved in several plant metabolic pathways. Our previous study indicated that foliar GSH application can increase zinc (Zn) levels in leafy vegetables. The objective of this study was to determine the mode of action of GSH as it relates to Zn transport from roots to shoots. Two types of transgenic Arabidopsis plants with genes for GSH synthesis, including StGCS-GS or AtGSH1 driven by the leaf-specific promoter of chlorophyll a/b-binding protein (pCab3) gene were generated. Both types of transgenic Arabidopsis plants showed significant increases in shoot GSH concentrations compared to the wild type (WT). Monitoring Zn movement by positron-emitting tracer imaging system (PETIS) analysis indicated that the Zn amount in the shoots of both types of transgenic Arabidopsis plants were higher than that in the WT. GSH concentration in phloem sap was increased significantly in WT with foliar applications of 10 mM GSH (WT-GSH), but not in transgenic Arabidopsis with elevated foliar GSH synthesis. Both types of transgenic Arabidopsis with elevated foliar GSH synthesis and WT-GSH exhibited increased shoot Zn concentrations and Zn translocation ratios. These results suggest that enhancement of endogenous foliar GSH synthesis and exogenous foliar GSH application affect root-to-shoot transport of Zn.
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http://dx.doi.org/10.1016/j.plantsci.2018.11.003DOI Listing
June 2019

Complete Genome Sequence of Plant Growth-Promoting Bacillus pumilus TUAT1.

Microbiol Resour Announc 2019 May 23;8(21). Epub 2019 May 23.

Institute of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, Japan

TUAT1 was isolated from soil in a university research field. Strain TUAT1 has the ability to promote the growth of plants, including that of rice, and has been commercialized as a biofertilizer. Here, we sequenced and annotated the genome of TUAT1 to understand the molecular mechanisms underlying its plant growth promotion.
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http://dx.doi.org/10.1128/MRA.00076-19DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6533381PMC
May 2019

Effects of Thiosulfate as a Sulfur Source on Plant Growth, Metabolites Accumulation and Gene Expression in Arabidopsis and Rice.

Plant Cell Physiol 2019 Aug;60(8):1683-1701

Institute of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, Japan.

Plants are considered to absorb sulfur from their roots in the form of sulfate. In bacteria like Escherichia coli, thiosulfate is a preferred sulfur source. It is converted into cysteine (Cys). This transformation consumes less NADPH and ATP than sulfate assimilation into Cys. In Saccharomyces cerevisiae, thiosulfate promoted growth more than sulfate. In the present study, the availability of thiosulfate, the metabolite transformations and gene expressions it induces were investigated in Arabidopsis and rice as model dicots and monocots, respectively. In Arabidopsis, the thiosulfate-amended plants had lower biomass than those receiving sulfate when sulfur concentrations in the hydroponic medium were above 300 μM. In contrast, rice biomass was similar for plants raised on thiosulfate and sulfate at 300 μM sulfur. Therefore, both plants can use thiosulfate but it is a better sulfur source for rice. In both plants, thiosulfate levels significantly increased in roots following thiosulfate application, indicating that the plants absorbed thiosulfate into their root cells. Thiosulfate is metabolized in plants by a different pathway from that used for sulfate metabolism. Thiosulfate increases plant sulfide and cysteine persulfide levels which means that plants are in a more reduced state with thiosulfate than with sulfate. The microarray analysis of Arabidopsis roots revealed that 13 genes encoding Cys-rich proteins were upregulated more with thiosulfate than with sulfate. These results together with those of the widely targeted metabolomics analysis were used to proposes a thiosulfate assimilation pathway in plants.
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http://dx.doi.org/10.1093/pcp/pcz082DOI Listing
August 2019

Burkholderia and Paraburkholderia are Predominant Soybean Rhizobial Genera in Venezuelan Soils in Different Climatic and Topographical Regions.

Microbes Environ 2019 Mar 15;34(1):43-58. Epub 2019 Feb 15.

Institute of Agriculture, Tokyo University of Agriculture and Technology (TUAT).

The climate, topography, fauna, and flora of Venezuela are highly diverse. However, limited information is currently available on the characterization of soybean rhizobia in Venezuela. To clarify the physiological and genetic diversities of soybean rhizobia in Venezuela, soybean root nodules were collected from 11 soil types located in different topographical regions. A total of 395 root nodules were collected and 120 isolates were obtained. All isolates were classified in terms of stress tolerance under different concentrations of NaCl and Al. The tolerance levels of isolates to NaCl and Al varied. Based on sampling origins and stress tolerance levels, 44 isolates were selected for further characterization. An inoculation test indicated that all isolates showed the capacity for root nodulation on soybean. Based on multilocus sequence typing (MLST), 20 isolates were classified into the genera Rhizobium and Bradyrhizobium. The remaining 24 isolates were classified into the genus Burkholderia or Paraburkholderia. There is currently no evidence to demonstrate that the genera Burkholderia and Paraburkholderia are the predominant soybean rhizobia in agricultural fields. Of the 24 isolates classified in (Para) Burkholderia, the nodD-nodB intergenic spacer regions of 10 isolates and the nifH gene sequences of 17 isolates were closely related to the genera Rhizobium and Bradyrhizobium, respectively. The root nodulation numbers of five (Para) Burkholderia isolates were higher than those of the 20 α-rhizobia. Furthermore, among the 44 isolates tested, one Paraburkholderia isolate exhibited the highest nitrogen-fixation activity in root nodules.
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http://dx.doi.org/10.1264/jsme2.ME18076DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6440732PMC
March 2019

Evaluation of Immune Responses Induced by Simultaneous Inoculations of Soybean (Glycine max [L.] Merr.) with Soil Bacteria and Rhizobia.

Microbes Environ 2019 Mar 5;34(1):64-75. Epub 2019 Feb 5.

Institute of Agriculture, TUAT.

Legumes form root nodules and fix atmospheric nitrogen by establishing symbiosis with rhizobia. However, excessive root nodules are harmful to plants because of the resulting overconsumption of energy from photosynthates. The delay of an inoculation of the soybean super-nodulation mutant NOD1-3 with Bradyrhizobium diazoefficiens USDA110 by 5 d after an inoculation with several soil bacteria confirmed that one bacterial group significantly decreased root nodules throughout the study period. Moreover, no significant changes were observed in nitrogen fixation by root nodules between an inoculation with USDA 110 only and co-inoculation treatments. To clarify the potential involvement of PR proteins in the restriction of nodule formation in the plants tested, the relative expression levels of PR-1, PR-2, PR-5, and PDF1.2 in NOD1-3 roots were measured using real-time PCR. One group of soil bacteria (Gr.3), which markedly reduced nodule numbers, significantly induced the expression of PR-1, PR-5 and PDF1.2 genes by day 5 after the inoculation. By days 7, 10, and 20 after the inoculation, the expression levels of PR-2 and PR-5 were lower than those with the uninoculated treatment. Inoculations with this group of soil bacteria resulted in lower root nodule numbers than with other tested soil bacteria exerting weak inhibitory effects on nodulation, and were accompanied by the induction of plant defense-related genes. Thus, PR genes appear to play important roles in the mechanisms that suppresses nodule formation on soybean roots.
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http://dx.doi.org/10.1264/jsme2.ME18110DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6440728PMC
March 2019

AtOPT6 Protein Functions in Long-Distance Transport of Glutathione in Arabidopsis thaliana.

Plant Cell Physiol 2018 Jul;59(7):1443-1451

Institute of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo, Japan.

The involvement of the Arabidopsis oligopeptide transporter AtOPT6, which was previously shown to take up glutathione (GSH) when expressed in yeast cells or in Xenopus laevis oocytes, in GSH transport was analyzed using opt6 knockout mutant lines. The concentration of GSH in flowers or siliques was lower in opt6 mutants relative to wild-type plants, suggesting involvement of AtOPT6 in long-distance transport of GSH. The GSH concentration in phloem sap was similar between opt6 mutants and wild-type plants. These results, combined with earlier reports showing expression of AtOPT6 in the vascular bundle, especially in the cambial zone, suggest that AtOPT6 functions to transport GSH into cells surrounding the phloem in sink organs. The opt6 mutant plants showed delayed bolting, implying the importance of AtOPT6 for regulation of the transition from vegetative to reproductive growth. After cadmium (Cd) treatment, the concentration of the major phytochelatin PC2 was lower in flowers in the opt6 mutants and Cd was accumulated in roots of opt6 mutant plants compared with wild-type plants. These results suggest that AtOPT6 is likely to be involved in transporting GSH, PCs and Cd complexed with these thiols into sink organs.
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http://dx.doi.org/10.1093/pcp/pcy074DOI Listing
July 2018

In vitro rhizobia response and symbiosis process under aluminum stress.

Can J Microbiol 2018 Aug 5;64(8):511-526. Epub 2018 Apr 5.

c Institute of Agriculture, Tokyo University of Agriculture and Technology, Saiwai-cho 3-5-8, Fuchu, Tokyo, Japan.

Aluminum (Al) toxicity is a major problem affecting soil fertility, microbial diversity, and nutrient uptake of plants. Rhizobia response and legume interaction under Al conditions are still unknown; it is important to understand how to develop and improve legume cultivation under Al stress. In this study, rhizobia response was recorded under different Al concentrations. Al effect on rhizobial cells was characterized by combination with different two pH conditions. Symbiosis process was compared between α- and β-rhizobia inoculated onto soybean varieties. Rhizobial cell numbers was decreased as Al concentration increased. However, induced Al tolerance considerably depended on rhizobia types and their origins. Accordingly, organic acid results were in correlation with growth rate and cell density which suggested that citric acid might be a positive selective force for Al tolerance and plant interaction on rhizobia. Al toxicity delayed and interrupted the plant-rhizobia interaction and the effect was more pronounced under acidic conditions. Burkholderia fungorum VTr35 significantly improved plant growth under acid-Al stress in combination with all soybean varieties. Moreover, plant genotype was an important factor to establish an effective nodulation and nitrogen fixation under Al stress. Additionally, tolerant rhizobia could be applied as an inoculant on stressful agroecosystems. Furthermore, metabolic pathways have still been unknown under Al stress.
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http://dx.doi.org/10.1139/cjm-2018-0019DOI Listing
August 2018

Identification of C-terminal Regions in Arabidopsis thaliana Phytochelatin Synthase 1 Specifically Involved in Activation by Arsenite.

Plant Cell Physiol 2018 Mar;59(3):500-509

Department of Public Health, School of Pharmacy, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo, 108-8641 Japan.

Phytochelatins (PCs) are major chelators of toxic elements including inorganic arsenic (As) in plant cells. Their synthesis confers tolerance and influences within-plant mobility. Previous studies had shown that various metal/metalloid ions differentially activate PC synthesis. Here we identified C-terminal parts involved in arsenite- [As(III)] dependent activation of AtPCS1, the primary Arabidopsis PC synthase. The T-DNA insertion in the AtPCS1 mutant cad1-6 causes a truncation in the C-terminal regulatory domain that differentially affects activation by cadmium (Cd) and zinc (Zn). Comparisons of cad1-6 with the AtPCS1 null mutant cad1-3 and the double mutant of tonoplast PC transporters abcc1/2 revealed As(III) hypersensitivity of cad1-6 equal to that of cad1-3. Both cad1-6 and cad1-3 showed increased As distribution to shoots compared with Col-0, whereas Zn accumulation in shoots was equally lower in cad1-6 and cad1-3. Supporting these phenotypes of cad1-6, PC accumulation in the As(III)-exposed plants were at trace level in both cad1-6 and cad1-3, suggesting that the truncated AtPCS1 of cad1-6 is defective in PCS activity in response to As(III). Analysis of a C-terminal deletion series of AtPCS1 using the PCS-deficient mutant of fission yeast suggested important regions within the C-terminal domain for As(III)-dependent PC synthesis, which were different from the regions previously suggested for Cd- or Zn-dependent activation. Interestingly, we identified a truncated variant more strongly activated than the wild-type protein. This variant could potentially be used as a tool to better restrict As mobility in plants.
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http://dx.doi.org/10.1093/pcp/pcx204DOI Listing
March 2018

Phytochelatin Synthase has Contrasting Effects on Cadmium and Arsenic Accumulation in Rice Grains.

Plant Cell Physiol 2017 Oct;58(10):1730-1742

Department of Plant Physiology, University of Bayreuth, Universitätsstrasse 30, D-95440 Bayreuth, Germany.

Phytochelatin (PC) synthesis has been well demonstrated as a major metal tolerance mechanism in Arabidopsis thaliana, whereas its contribution to long-distance element transport especially in monocots remains elusive. Using rice as a cereal model, we examined physiological roles of Oryza sativa phytochelatin synthase 1 (OsPCS1) in the distribution and detoxification of arsenic (As) and cadmium (Cd), two toxic elements associated with major food safety concerns. First, we isolated four different transcript variants of OsPCS1 as well as one from OsPCS2. Quantitative real-time reverse transcription-PCR (RT-PCR) of each OsPCS transcript in rice seedlings suggested that expression of OsPCS1full, the longest OsPCS1 variant, was most abundant, followed by OsPCS2. Heterologous expression of OsPCS variants in PCS-deficient mutants of Schizosaccharomyces pombe and A. thaliana suggested that OsPCS1full possessed PCS activity in response to As(III) and Cd while the activity of other PCS variants was very low. To address physiological functions in toxic element tolerance and accumulation, two independent OsPCS1 mutant rice lines (a T-DNA and a Tos17 insertion line) were identified. The OsPCS1 mutants exhibited increased sensitivity to As(III) and Cd in hydroponic experiments, showing the importance of OsPCS1-dependent PC synthesis for rice As(III) and Cd tolerance. Elemental analyses of rice plants grown in soil with environmentally relevant As and Cd concentrations showed increased As accumulation and decreased Cd accumulation in grains of the T-DNA line. The Tos17 mutant also exhibited the reduced Cd accumulation phenotype. These contrasting effects on As and Cd distribution to grains suggest the existence of at least partially distinct PC-dependent pathways for As and Cd.
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http://dx.doi.org/10.1093/pcp/pcx114DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5914395PMC
October 2017

Plants prioritize phytochelatin synthesis during cadmium exposure even under reduced sulfate uptake caused by the disruption of SULTR1;2.

Plant Signal Behav 2017 05 9;12(5):e1325053. Epub 2017 May 9.

a Graduate School of Agricultural Science , Kyushu University , Hakozaki, Higashi-ku, Fukuoka , Japan.

Glutathione and phytochelatins are sulfur containing compounds playing an important role in cadmium (Cd) detoxification. We examined the Cd-induced changes in the percentage of sulfur containing compounds to total sulfur in wild-type and sulfate transporter 1;2 knockout mutant, sel1-10. Cd treatment increased the proportion of sulfate and thiols in the total sulfur content. Among the thiols analyzed, the proportion of cysteine and glutathione were decreased by the Cd treatment and that of the phytochelatins were increased. Although the total sulfur content in sel1-10 was decreased compared with that in wild-type, the percentages of individual thiol in the total thiol content were similarly maintained between sel1-10 and wild-type, suggesting that plants tightly controlled the balance of each thiol under Cd treatment.
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http://dx.doi.org/10.1080/15592324.2017.1325053DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5501232PMC
May 2017

Genetic Characterization of Soybean Rhizobia Isolated from Different Ecological Zones in North-Eastern Afghanistan.

Microbes Environ 2017 Mar 17;32(1):71-79. Epub 2017 Mar 17.

United Graduate School of Agriculture, Tokyo University of Agriculture and Technology.

Seventy rhizobial isolates were obtained from the root nodules of two soybean (Glycine max) cultivars: Japanese cultivar Enrei and USA cultivar Stine3300, which were inoculated with different soil samples from Afghanistan. In order to study the genetic properties of the isolates, the DNA sequences of the 16S rRNA gene and symbiotic genes (nodD1 and nifD) were elucidated. Furthermore, the isolates were inoculated into the roots of two soybean cultivars, and root nodule numbers and nitrogen fixation abilities were subsequently evaluated in order to assess symbiotic performance. Based on 16S rRNA gene sequences, the Afghanistan isolates obtained from soybean root nodules were classified into two genera, Bradyrhizobium and Ensifer. Bradyrhizobium isolates accounted for 54.3% (38) of the isolates, and these isolates had a close relationship with Bradyrhizobium liaoningense and B. yuanmingense. Five out of the 38 Bradyrhizobium isolates showed a novel lineage for B. liaoningense and B. yuanmingense. Thirty-two out of the 70 isolates were identified as Ensifer fredii. An Ensifer isolate had identical nodD1 and nifD sequences to those in B. yuanmingense. This result indicated that the horizontal gene transfer of symbiotic genes occurred from Bradyrhizobium to Ensifer in Afghanistan soil. The symbiotic performance of the 14 tested isolates from the root nodules of the two soybean cultivars indicated that Bradyrhizobium isolates exhibited stronger acetylene reduction activities than Ensifer isolates. This is the first study to genetically characterize soybean-nodulating rhizobia in Afghanistan soil.
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http://dx.doi.org/10.1264/jsme2.ME16119DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5371078PMC
March 2017

Post-Translational Regulation of the Dicing Activities of Arabidopsis DICER-LIKE 3 and 4 by Inorganic Phosphate and the Redox State.

Plant Cell Physiol 2017 03;58(3):485-495

Department of Applied Biological Sciences, Tokyo University of Agriculture and Technology, Saiwaicho, Fuchu, Tokyo, Japan.

In Arabidopsis thaliana, small interfering RNAs (siRNAs) generated by two Dicer isoforms, DCL3 and DCL4, function in distinct epigenetic processes, i.e. RNA-directed DNA methylation and post-transcriptional gene silencing, respectively. Plants often respond to their environment by producing a distinct set of small RNAs; however, the mechanism for controlling the production of different siRNAs from the same dsRNA substrate remains unclear. We established a simple biochemical method to visualize the dsRNA-cleaving activities of DCL3 and DCL4 in cell-free extracts prepared from Arabidopsis seedlings. Here, we demonstrate that different nutrient statuses of a host plant affect the post-translational regulation of the dicing activity of DCL3 and DCL4. Phosphate deficiency inhibited DCL3, and the activity of DCL3 was directly activated by inorganic phosphate. Sulfur deficiency inhibited DCL4 but not DCL3, and the activity of DCL4 was recovered by supplementation of the cell-free extracts with reductants containing a thiol group. Immunopurified DCL4 was activated by recombinant Arabidopsis thioredoxin-h1 with dithiothreitol. Therefore, DCL4 is subject to redox regulation. These results demonstrate that post-translational regulation of DCL activities fine-tunes the balance between branches of the gene silencing pathway according to the growth environment.
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http://dx.doi.org/10.1093/pcp/pcw226DOI Listing
March 2017

Effects of Cadmium Treatment on the Uptake and Translocation of Sulfate in Arabidopsis thaliana.

Plant Cell Physiol 2016 Nov 1;57(11):2353-2366. Epub 2016 Sep 1.

Graduate School of Agricultural Science, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan

Cadmium (Cd) is a highly toxic and non-essential element for plants, whereas phytochelatins and glutathione are low-molecular-weight sulfur compounds that function as chelators and play important roles in detoxification. Cadmium exposure is known to induce the expression of sulfur-assimilating enzymes and sulfate uptake by roots. However, the molecular mechanism underlying Cd-induced changes remains largely unknown. Accordingly, we analyzed the effects of Cd treatment on the uptake and translocation of sulfate and accumulation of thiols in Arabidopsis thaliana Both wild type (WT) and null mutant (sel1-10 and sel1-18) plants of the sulfate transporter SULTR1;2 exhibited growth inhibition when treated with CdCl However, the mutant plants exhibited a lower growth rate and lower Cd accumulation. Cadmium treatment also upregulated the transcription of SULTR1;2 and sulfate uptake activity in WT plants, but not in mutant plants. In addition, the sulfate, phytochelatin and total sulfur contents were preferentially accumulated in the shoots of both WT and mutant plants treated with CdCl, and sulfur K-edge XANES spectra suggested that sulfate was the main compound responsible for the increased sulfur content in the shoots of CdCl-treated plants. Our results demonstrate that Cd-induced sulfate uptake depends on SULTR1;2 activity, and that CdCl treatment greatly shifts the distribution of sulfate to shoots, increases the sulfate concentration of xylem sap and upregulates the expression of SULTRs involved in root-to-shoot sulfate transport. Therefore, we conclude that root-to-shoot sulfate transport is stimulated by Cd and suggest that the uptake and translocation of sulfate in CdCl-treated plants are enhanced by demand-driven regulatory networks.
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http://dx.doi.org/10.1093/pcp/pcw156DOI Listing
November 2016

Growth Rate of and Gene Expression in Bradyrhizobium diazoefficiens USDA110 due to a Mutation in blr7984, a TetR Family Transcriptional Regulator Gene.

Microbes Environ 2016 Sep 5;31(3):249-59. Epub 2016 Jul 5.

Institute of Agriculture, Tokyo University of Agriculture and Technology.

Previous transcriptome analyses have suggested that a gene cluster including a transcriptional regulator (blr7984) of the tetracycline repressor family was markedly down-regulated in symbiosis. Since blr7984 is annotated to be the transcriptional repressor, we hypothesized that it is involved in the repression of genes in the genomic cluster including blr7984 in symbiotic bacteroids. In order to examine the function and involvement of the blr7984 gene in differentiation into bacteroids, we compared the free-living growth/symbiotic phenotype and gene expression between a blr7984-knockout mutant and the wild-type strain of Bradyrhizobium diazoefficiens USDA110. The mutant transiently increased the cell growth rate under free-living conditions and nodule numbers over those with the wild-type strain USDA110. The expression of three genes adjacent to the disrupted blr7984 gene was strongly up-regulated in the mutant in free-living and symbiotic cells. The mutant also induced the expression of genes for glutathione S-transferase, cytochrome c oxidases, ABC transporters, PTS sugar transport systems, and flagella synthesis under free-living conditions. bll7983 encoding glutathione S-transferase was up-regulated the most by the blr7984 disruption. Since redox regulation by glutathione is known to be involved in cell division in prokaryotes and eukaryotes, the strong expression of glutathione S-transferase encoded by the bll7983 gene may have caused redox changes in mutant cells, which resulted in higher rates of cell division.
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http://dx.doi.org/10.1264/jsme2.ME16056DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5017801PMC
September 2016

Genotypic difference in (137)Cs accumulation and transfer from the contaminated field in Fukushima to azuki bean (Vigna angularis).

J Environ Radioact 2016 Jul 19;158-159:138-47. Epub 2016 Apr 19.

Instutute of Agriculture, Tokyo University of Agriculture and Technology, Saiwaicho 3-5-8, Fuchu, Tokyo, 183-8509, Japan. Electronic address:

The screening of mini-core collection of azuki bean accessions (Vigna angularis (Willd.) Ohwi & Ohashi) for comparative uptake of (137)Cs in their edible portions was done in field trials on land contaminated by the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. Ninety seven azuki bean accessions including their wild relatives from a Japanese gene bank, were grown in a field in the Fukushima prefecture, which is located approximately 51 km north of FDNPP. The contamination level of the soil was 3665 ± 480 Bq kg(-1) dry weight ((137)Cs, average ± SD). The soil type comprised clay loam, where the sand: silt: clay proportion was 42:21:37. There was a significant varietal difference in the biomass production, radiocaesium accumulation and transfer factor (TF) of radiocaesium from the soil to edible portion. Under identical agricultural practice, the extent of (137)Cs accumulation by seeds differed between the accessions by as much as 10-fold. Inter-varietal variation was expressed at the ratio of the maximum to minimum observed (137)Cs transfer factor for seeds ranged from 0.092 to 0.009. The total biomass, time to flowering and maturity, and seed yield had negative relationship to (137)Cs activity concentration in seeds. The results suggest that certain variety/varieties of azuki bean which accumulated less (137)Cs in edible portion with preferable agronomic traits are suitable to reduce the (137)Cs accumulation in food chain on contaminated land.
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http://dx.doi.org/10.1016/j.jenvrad.2016.04.011DOI Listing
July 2016

Growth and (137)Cs uptake and accumulation among 56 Japanese cultivars of Brassica rapa, Brassica juncea and Brassica napus grown in a contaminated field in Fukushima: Effect of inoculation with a Bacillus pumilus strain.

J Environ Radioact 2016 Jun 14;157:27-37. Epub 2016 Mar 14.

Institute of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan. Electronic address:

Fifty six local Japanese cultivars of Brassica rapa (40 cultivars), Brassica juncea (10 cultivars) and Brassica napus (6 cultivars) were assessed for variability in growth and (137)Cs uptake and accumulation in association with a Bacillus pumilus strain. Field trial was conducted at a contaminated farmland in Nihonmatsu city, in Fukushima prefecture. Inoculation resulted in different responses of the cultivars in terms of growth and radiocesium uptake and accumulation. B. pumilus induced a significant increase in shoot dry weight in 12 cultivars that reached up to 40% in one B. rapa and three B. juncea cultivars. Differences in radiocesium uptake were observed between the cultivars of each Brassica species. Generally, inoculation resulted in a significant increase in (137)Cs uptake in 22 cultivars, while in seven cultivars it was significantly decreased. Regardless of plant cultivar and bacterial inoculation, the transfer of (137)Cs to the plant shoots (TF) varied by a factor of up to 5 and it ranged from to 0.011 to 0.054. Five inoculated cultivars, showed enhanced shoot dry weights and decreased (137)Cs accumulations, among which two B. rapa cultivars named Bitamina and Nozawana had a significantly decreased (137)Cs accumulation in their shoots. Such cultivars could be utilized to minimize the entry of radiocesium into the food chain; however, verifying the consistency of their radiocesium accumulation in other soils is strongly required. Moreover, the variations in growth and radiocesium accumulation, as influenced by Bacillus inoculation, could help selecting well grown inoculated Brassica cultivars with low radiocesium accumulation in their shoots.
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http://dx.doi.org/10.1016/j.jenvrad.2016.02.024DOI Listing
June 2016

Relations of fine-root morphology on (137)Cs uptake by fourteen Brassica species.

J Environ Radioact 2015 Dec 7;150:203-12. Epub 2015 Sep 7.

Leibniz Centre for Agricultural Landscape Research, Institute of Land Use Systems, Eberswalder str. 84, 15374, Muencheberg, Germany. Electronic address:

Fourteen Brassica species consisting of seven leafy vegetables and seven root vegetables were examined for (137)Cs uptake differences in relation to their fine-root morphological characters. A pot experiment was conducted from November 2014 to February 2015 in a Phytroton using a contaminated soil of Fukushima prefecture. Leafy vegetables showed bigger root diameters, larger root surface area and larger root volume. Consequently, leafy vegetables had higher (137)Cs uptake compared to root vegetables. Among the three fine-root parameters, only root surface area was observed as a significant contributing factor to higher (137)Cs uptake in terms of transfer factor (TF, dry weight basis). Kakina exhibited higher (137)Cs TF value (0.20) followed by Chinese cabbage (0.18) and mizuna (0.17). Lower TF values were observed in turnip (0.059), rutabaga (Kitanoshou) (0.062) and radish (Ha daikon) (0.064).
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http://dx.doi.org/10.1016/j.jenvrad.2015.08.023DOI Listing
December 2015
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