Time filter

Source Type

News Article | November 4, 2016
Site: www.eurekalert.org

In research published in The Plant Journal, a group of scientists led by researchers from the RIKEN Center for Sustainable Resource Science in Japan have decoded the genome of Glycyrrhiza uralensis, or Chinese licorice, a plant that is important for its use in Chinese medicine and as a natural sweetener. Chinese licorice, which is closely related to the plant--Glycyrrhiza glabra--used for licorice candy, is an important component of Chinese traditional medicine. According to Kazuki Saito of CSRS, who led the team, "It is incorporated in approximately 70 percent of the 200 major formulations used in traditional Kampo medicine in Japan. Considering that 90 percent of Japanese physicians prescribe Kampo medicine in their practices, it is easy to see the importance of this plant." The team chose to examine the genome of Chinese licorice rather than other related species partly because it is known to contain the highest concentration of glycyrrhizin, a compound that is associated with the medical properties of the plant, which include anti-inflammatory, anti-cancer, anti-allergic, and anti-viral activities. To conduct the screening, they chose a strain of G. uralensis kept at the Takeda Garden for Medicinal Plant Conservation in Kyoto. Using a combination of long read and short read sequencing, and by comparing the genome to published sequences of other legume species, they predicted that the plant's genome coded just over 34,000 proteins, a number somewhat higher than the 20,000 in the human genome. They focused in particular on two genetic regions--one coding saponins, which are important plant compounds including glycyrrhizin, and the other producing isoflavonoids, which are also known as medicinal components. Through the research, the group demonstrated that there is a close conservation of genes between licorice and other related plants such as barrelclover (s species close to alfalfa) and chickpea, showing that legumes use a small number of genes to create "scaffolds" that allow for the production of an enormous diversity of compounds. Keiichi Mochida, the first author of the paper, says, "Chinese licorice is an important and heavily consumed medicinal plant, and we hope that our work will make it possible to carry out molecular breeding to create strains that will grow sustainably in Japan, and which produce large concentrations of useful compounds such as glycyrrhizin." According to Saito, "We very much hope that our draft genome sequence will facilitate the identification, isolation, and editing of useful genes to improve the agronomic and medicinal traits of licorice through molecular breeding. There remains much to learn about the immense diversity of plant metabolism, and this research will contribute to further progress in that direction." The group plans to do further work to examines differences between the genome of G. uralensis and other licorice species, to further deepen their understanding of the production of useful compounds. The work was carried out by RIKEN CSRS in collaboration with a group including Chiba University, Kochi University, and Osaka University.


News Article | November 4, 2016
Site: www.sciencedaily.com

In research published in The Plant Journal, a group of scientists led by researchers from the RIKEN Center for Sustainable Resource Science in Japan have decoded the genome of Glycyrrhiza uralensis, or Chinese licorice, a plant that is important for its use in Chinese medicine and as a natural sweetener. Chinese licorice, which is closely related to the plant -- Glycyrrhiza glabra -- used for licorice candy, is an important component of Chinese traditional medicine. According to Kazuki Saito of CSRS, who led the team, "It is incorporated in approximately 70 percent of the 200 major formulations used in traditional Kampo medicine in Japan. Considering that 90 percent of Japanese physicians prescribe Kampo medicine in their practices, it is easy to see the importance of this plant." The team chose to examine the genome of Chinese licorice rather than other related species partly because it is known to contain the highest concentration of glycyrrhizin, a compound that is associated with the medical properties of the plant, which include anti-inflammatory, anti-cancer, anti-allergic, and anti-viral activities. To conduct the screening, they chose a strain of G. uralensis kept at the Takeda Garden for Medicinal Plant Conservation in Kyoto. Using a combination of long read and short read sequencing, and by comparing the genome to published sequences of other legume species, they predicted that the plant's genome coded just over 34,000 proteins, a number somewhat higher than the 20,000 in the human genome. They focused in particular on two genetic regions -- one coding saponins, which are important plant compounds including glycyrrhizin, and the other producing isoflavonoids, which are also known as medicinal components. Through the research, the group demonstrated that there is a close conservation of genes between licorice and other related plants such as barrelclover (s species close to alfalfa) and chickpea, showing that legumes use a small number of genes to create "scaffolds" that allow for the production of an enormous diversity of compounds. Keiichi Mochida, the first author of the paper, says, "Chinese licorice is an important and heavily consumed medicinal plant, and we hope that our work will make it possible to carry out molecular breeding to create strains that will grow sustainably in Japan, and which produce large concentrations of useful compounds such as glycyrrhizin." According to Saito, "We very much hope that our draft genome sequence will facilitate the identification, isolation, and editing of useful genes to improve the agronomic and medicinal traits of licorice through molecular breeding. There remains much to learn about the immense diversity of plant metabolism, and this research will contribute to further progress in that direction." The group plans to do further work to examines differences between the genome of G. uralensis and other licorice species, to further deepen their understanding of the production of useful compounds. The work was carried out by RIKEN CSRS in collaboration with a group including Chiba University, Kochi University, and Osaka University.


Nakabayashi R.,Center for Sustainable Resource Science | Mori T.,Center for Sustainable Resource Science | Saito K.,Center for Sustainable Resource Science | Saito K.,Chiba University
Plant Signaling and Behavior | Year: 2014

Plants have developed mechanisms to protect themselves against both biotic and abiotic environmental stress. Specialized/secondary metabolism is one of the stress response mechanisms. Recently, we reported that flavonoids, a class of specialized metabolites, including flavonols and anthocyanins with strong radical scavenging activity contributed to the mitigation of oxidative and drought stress in Arabidopsis thaliana (Arabidopsis). However, the behavior of flavonoids during drought stress is still not well-documented. Herein we investigated the time-series alternation of flavonoids in the aerial part of Arabidopsis (wild type, Col-0) during drought stress by LC-QTO F-MS. The drastic alternation of 5 flavonols and 5 anthocyanins was revealed together with changes in marker metabolites of drought stress, e.g., proline, raffinose, and galactinol. These findings indicate that flavonols and anthocyanins can mitigate drought stress. © 2014 Landes Bioscience.


PubMed | University of Michigan, Max Planck Institute for Evolutionary Anthropology, Tokyo Electron, Azabu University and 6 more.
Type: Journal Article | Journal: Cell | Year: 2015

Intestinal Th17 cells are induced and accumulate in response to colonization with a subgroup of intestinal microbes such as segmented filamentous bacteria (SFB) and certain extracellular pathogens. Here, we show that adhesion of microbes to intestinal epithelial cells (ECs) is a critical cue for Th17 induction. Upon monocolonization of germ-free mice or rats with SFB indigenous to mice (M-SFB) or rats (R-SFB), M-SFB and R-SFB showed host-specific adhesion to small intestinal ECs, accompanied by host-specific induction of Th17 cells. Citrobacter rodentium and Escherichia coli O157 triggered similar Th17 responses, whereas adhesion-defective mutants of these microbes failed to do so. Moreover, a mixture of 20 bacterial strains, which were selected and isolated from fecal samples of a patient with ulcerative colitis on the basis of their ability to cause a robust induction of Th17 cells in the mouse colon, also exhibited EC-adhesive characteristics.


Atarashi K.,RIKEN | Atarashi K.,Keio University | Tanoue T.,RIKEN | Ando M.,Yakult Central Institute | And 34 more authors.
Cell | Year: 2015

Intestinal Th17 cells are induced and accumulate in response to colonization with a subgroup of intestinal microbes such as segmented filamentous bacteria (SFB) and certain extracellular pathogens. Here, we show that adhesion of microbes to intestinal epithelial cells (ECs) is a critical cue for Th17 induction. Upon monocolonization of germ-free mice or rats with SFB indigenous to mice (M-SFB) or rats (R-SFB), M-SFB and R-SFB showed host-specific adhesion to small intestinal ECs, accompanied by host-specific induction of Th17 cells. Citrobacter rodentium and Escherichia coli O157 triggered similar Th17 responses, whereas adhesion-defective mutants of these microbes failed to do so. Moreover, a mixture of 20 bacterial strains, which were selected and isolated from fecal samples of a patient with ulcerative colitis on the basis of their ability to cause a robust induction of Th17 cells in the mouse colon, also exhibited EC-adhesive characteristics. © 2015 Elsevier Inc.


PubMed | Kobe University, Niigata University, Center for Sustainable Resource Science, Watanabe Seed Co. and 2 more.
Type: | Journal: BMC plant biology | Year: 2016

Heterosis or hybrid vigour is a phenomenon in which hybrid progeny exhibit superior performance compared to their parental inbred lines. Most commercial Chinese cabbage cultivars are F1 hybrids and their level of hybrid vigour is of critical importance and is a key selection criterion in the breeding system.We have characterized the heterotic phenotype of one F1 hybrid cultivar of Chinese cabbage and its parental lines from early- to late-developmental stages of the plants. Hybrid cotyledons are larger than those of the parents at 4 days after sowing and biomass in the hybrid, determined by the fresh weight of leaves, is greater than that of the larger parent line by approximately 20% at 14 days after sowing. The final yield of the hybrid harvested at 63 days after sowing is 25% greater than the yield of the better parent. The larger leaves of the hybrid are a consequence of increased cell size and number of the photosynthetic palisade mesophyll cells and other leaf cells. The accumulation of plant hormones in the F1 was within the range of the parental levels at both 2 and 10 days after sowing. Two days after sowing, the expression levels of chloroplast-targeted genes in the cotyledon cells were upregulated in the F1 hybrid relative to their mid parent values. Shutdown of chlorophyll biosynthesis in the cotyledon by norflurazon prevented the increased leaf area in the F1 hybrid.In the cotyledons of F1 hybrids, chloroplast-targeted genes were upregulated at 2 days after sowing. The increased activity levels of this group of genes suggested that their differential transcription levels could be important for establishing early heterosis but the increased transcription levels were transient. Inhibition of the photosynthetic process in the cotyledon reduced heterosis in later seedling stages. These observations suggest early developmental events in the germinating seedling of the hybrid may be important for later developmental vigour and yield advantage.


PubMed | Kanto Gakuin University, Yokohama City University, Center for Sustainable Resource science and University of Tokyo
Type: Journal Article | Journal: PloS one | Year: 2017

Profiling elemental contents in wheat grains and clarifying the underlying genetic systems are important for the breeding of biofortified crops. Our objective was to evaluate the genetic potential of 269 Afghan wheat landraces for increasing elemental contents in wheat cultivars. The contents of three major (Mg, K, and P) and three minor (Mn, Fe, and Zn) elements in wheat grains were measured by energy dispersive X-ray fluorescence spectrometry. Large variations in elemental contents were observed among landraces. Marker-based heritability estimates were low to moderate, suggesting that the elemental contents are complex quantitative traits. Genetic correlations between two locations (Japan and Afghanistan) and among the six elements were estimated using a multi-response Bayesian linear mixed model. Low-to-moderate genetic correlations were observed among major elements and among minor elements respectively, but not between major and minor elements. A single-response genome-wide association study detected only one significant marker, which was associated with Zn, suggesting it will be difficult to increase the elemental contents of wheat by conventional marker-assisted selection. Genomic predictions for major elemental contents were moderately or highly accurate, whereas those for minor elements were mostly low or moderate. Our results indicate genomic selection may be useful for the genetic improvement of elemental contents in wheat.


News Article | December 16, 2015
Site: phys.org

Researchers at the RIKEN Center for Sustainable Resource Science and the University of Tokyo have demonstrated that the bacterium Acidithiobacillus ferrooxidans can take electrons needed for growth directly from an electrode power source when iron—its already known source of energy—is absent. The study, published in Frontiers in Microbiology, shows that A. ferrooxidans can use direct uptake of electrons from an electrode to fuel the same metabolic pathway that is activated by the oxidation of diffusible iron ions. Just as plants with chlorophyll use photosynthesis to convert energy from light into sugars needed for growth, other organisms—like animals—gain energy for the manufacture of sugars by taking electrons from substances in their surrounding environments—a process called chemosynthesis. Organisms that gain their energy this way are called chemotrophs, and those that get their electrons through oxidation of inorganic substances are called chemolithoautotrophs. Phototrophs and chemotrophs make up two interconnected ecosystems. "We are investigating the possibility of a third type of ecosystem," explains group leader Ryuhei Nakamura. "We call it the electro-ecosystem because microbial activity is sustained primarily by direct electrical current." Recently, his team has discovered geo-electric currents across the walls of black-smoker chimneys formed by hydrothermanl vents, suggesting that some deep-sea microbes might double as a electrolithoautotrophs, organisms that can use electrical potential—meaning that they simply eat electrons—as an energy source instead of light or surrounding inorganic substances. Because access to microbes in this environment is not easy, and to verify their hypothesis that being able to switch energy sources from inorganic substances to electricity is not unique in the microbial world, the team experimented with A. ferrooxidans, a chemolithoautotrophic bacterium known to oxidize iron ions (Fe2+). The team cultured A. ferrooxidans in an Fe2+-free environment and supplied an electrode with an electrical potential of +0.4 V, carbon-dioxide as a carbon source, and oxygen as an electron acceptor. They found that these conditions created a current that originated from the electrode, and that the strength of the current depended on how many cells were attached to the electrode. Killing the cells with UV light immediately suppressed the current. To determine how this current was being generated, they used an artificial photochemical reaction. Normally, carbon monoxide attaches to heme proteins in A. ferrooxidans outer membranes and prevents oxidation. But, when exposed to light, this bond is broken and oxidation continues as usual. When tested, carbon-monoxide also prevented the current formed between the electrode and A. ferrooxidans cells and exposure to light reversed this block and allowed the current to flow. This suggested that a heme protein is needed for the electrosynthesis exhibited by A. ferrooxidans. Further analysis showed that the responsible heme protein is the aa3 complex which is known to play a role in down-hill electron transfer in A. ferrooxidans that generates ATP and the proton-motive-force that allows uphill electron transfer and carbon fixation—the hallmarks of sugar production. Inhibition of a protein complex that is part of the uphill-transfer process suppressed the current, showing that the proton-motive-forces being generated were indeed used for up-hill electron transport. Additionally, the optical density of cells cultured with the electrode for eight days increased over time, indicating growth and that the current generated by electrons flowing from the electrode to the cells was being used for carbon fixation. "Now that we have identified the metabolic pathway for electrolithoautotrophs in A. ferrooxidans, we will be able to apply this knowledge to bacteria we find in the deep sea vent," says Nakamura. "The next step is to prove the existence of electro-ecosystems in on-site deep-sea experiments." Understanding electro-ecosystems and how electrical currents can support life could lead to a blueprint for sustainable human ecosystems, using technology such as fuel cells, batteries, and thermoelectric converters." Explore further: Scientists trick iron-eating bacteria into breathing electrons instead More information: Takumi Ishii et al. From chemolithoautotrophs to electrolithoautotrophs: CO2 fixation by Fe(II)-oxidizing bacteria coupled with direct uptake of electrons from solid electron sources, Frontiers in Microbiology (2015). DOI: 10.3389/fmicb.2015.00994


Kanno Y.,Center for Sustainable Resource Science | Kamiya Y.,Center for Sustainable Resource Science | Seo M.,Center for Sustainable Resource Science
Plant Signaling and Behavior | Year: 2013

We identified a member of the Arabidopsis NRT 1/PTR FAMI LY (NPF), AtNPF4.6, as an abscisic acid (ABA) transporter, AIT 1. AtNPF4.6 was originally characterized as a low-affinity nitrate transporter NRT 1.2. We hypothesized that the competition between nitrate and ABA as substrates for AtNPF4.6 might be involved in the interactions between nitrate and ABA signaling. However, the ABA transport activity of AtNPF4.6 was not inhibited by an excess amount of nitrate. In addition, the npf4.6 mutant was less sensitive to ABA than the wild type during germination irrespective of nitrate concentrations in the media. Furthermore, nitrate promoted germination of both wild type and npf4.6 in the presence of ABA. These results do not support the idea of a physiological linkage between nitrate and ABA signals through AtNPF4.6. © 2013 Landes Bioscience.

Loading Center for Sustainable Resource Science collaborators
Loading Center for Sustainable Resource Science collaborators