Statistical method for testing the neutral mutation hypothesis by DNA polymorphism.

To cope with environmental fluctuations and to prevent invasion by pathogens, plant metabolism must be flexible and dynamic. Active oxygen species, whose formation is accelerated under stress conditions, must be rapidly processed if oxidative damage is to be averted. The lifetime of active oxygen species within the cellular environment is determined by the antioxidative system, which provides crucial protection against oxidative damage. The antioxidative system comprises numerous enzymes and compounds of low molecular weight. While research into the former has benefited greatly from advances in molecular technology, the pathways by which the latter are synthesized have received comparatively little attention. The present review emphasizes the roles of ascorbate and glutathione in plant metabolism and stress tolerance. We provide a detailed account of current knowledge of the biosynthesis, compartmentation, and transport of these two important antioxidants, with emphasis on the unique insights and advances gained by molecular exploration.

ASCORBATE AND GLUTATHIONE: Keeping Active Oxygen Under Control

1. Plant Nutrients. 2. The Soil as a Plant Nutrient Medium. 3. Nutrient Uptake and Assimilation. 4. Plant Water Relationships. 5. Plant Growth and Crop Production. 6. Fertilizer Application. 7. Nitrogen. 8. Sulphur. 9. Phosphorus. 10. Potassium. 11. Calcium. 12. Magnesium. 13. Iron. 14. Manganese. 15. Zinc. 16. Copper. 17. Molybdenum. 18. Boron. 19. Further Elements of Importance. 20. Elements with More Toxic Effects. General Readings. References. Index.

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Principles of plant nutrition

Gut commensal microbes shape the mucosal immune system by regulating the differentiation and expansion of several types of T cell. Clostridia, a dominant class of commensal microbe, can induce colonic regulatory T (Treg) cells, which have a central role in the suppression of inflammatory and allergic responses. However, the molecular mechanisms by which commensal microbes induce colonic Treg cells have been unclear. Here we show that a large bowel microbial fermentation product, butyrate, induces the differentiation of colonic Treg cells in mice. A comparative NMR-based metabolome analysis suggests that the luminal concentrations of short-chain fatty acids positively correlates with the number of Treg cells in the colon. Among short-chain fatty acids, butyrate induced the differentiation of Treg cells in vitro and in vivo, and ameliorated the development of colitis induced by adoptive transfer of CD4(+) CD45RB(hi) T cells in Rag1(-/-) mice. Treatment of naive T cells under the Treg-cell-polarizing conditions with butyrate enhanced histone H3 acetylation in the promoter and conserved non-coding sequence regions of the Foxp3 locus, suggesting a possible mechanism for how microbial-derived butyrate regulates the differentiation of Treg cells. Our findings provide new insight into the mechanisms by which host-microbe interactions establish immunological homeostasis in the gut.

Commensal microbe-derived butyrate induces the differentiation of colonic regulatory T cells

KEGG(Kyoto Encyclopedia of Genes and Genomes)〔和文〕 (特集 ゲノム医学の現在と未来--基礎と臨床) -- (データベース)

Triterpene saponins are widely distributed in higher plants [1,2] and belong to a class of natural products that includes various bioactive compounds found in medicinal plants [3]. The family Leguminosae, which includes plants such as licorice (Glycyrrhiza uralensis) [4], soybean (Glycine max) [5] and alfalfa (Medicago sativa) [6], are well-known triterpene saponin-producing plants. The roots and stolons of licorice accumulate glycyrrhizin as a major bioactive triterpene saponin, while the hypocotyls of soybean accumulate soyasaponin I. Glycyrrhizin and soyasaponin I are synthesized from a common biosynthetic intermediate, the triterpene aglycone b-amyrin, derived from the initial cyclization of 2,3-oxidosqualene. Licorice b-amyrin 11-hydroxylase (CYP88D6) [7] and b-amyrin 30-hydroxylase (CYP72A154) [8] catalyze the oxidation of b-amyrin at positions C-11 (two-step oxidation) and C-30 (three-step oxidation), respectively, to produce glycyrrhetinic acid, the triterpene aglycone of glycyrrhizin. In contrast, soybean b-amyrin 22-hydroxylase [unpublished] and b-amyrin 24-hydroxylase (CYP93E1) [9] catalyze the oxidation of b-amyrin at positions C-22 (one-step oxidation) and C-24 (one-step oxidation), respectively, to produce soyasapogenol B (22-hydroxy, 24-hydroxyb-amyrin), the triterpene aglycone of soyasaponin I (Figure 12.1). Construction of vector plasmids for multi-gene transformation is an essential technique for pathway engineering of secondary metabolites. The construction of complex plasmids for expressing multiple genes is considered to be a timeconsuming process, but we were able to reduce the difficulty by connecting the gene cassettes in tandem at the restriction sites of homing endonucleases [10], which recognize 18 to 39 specific bases, and using a polymerase chain reaction (PCR) technique based on primer overlap extension [11]. The terminator regulates the level of expression by controlling transcriptional termination and 30-endprocessing of mRNA. Arabidopsis heat shock protein18.2

Multi‐Gene Transformation for Pathway Engineering of Secondary Metabolites

The present invention provides a gene that codes for a protein, wherein the protein is an anthocyanin 5-O-glucosyltransferase, which is an enzyme that transfers a glycoside to the 5 position of a flavonoid. The disclosed anthocyanin 5-O-glucosyltransferases were isolated from Perilla fruescens, Verbena hybrida, Torenia hybrida , and Petunia hybrida . Also disclosed are genes that code for a protein having a modified amino acid sequence relative to the above amino acid sequence and having activity that transfers a glycoside to the 5 position of a flavonoid, and a process for producing the above protein using said gene. This gene can be used to artificially alter the color of plants.

Proteins having a flavonoid 5-O-glycosyltransferase activity (5GT)

A group of anti-nutritional specialized metabolites called steroidal glycoalkaloids (SGAs) are produced in Solanum species such as tomato, potato, and eggplant. The transcription factor JASMONATE-RESPONSIVE ETHYLENE RESPONSE FACTOR 4 (JRE4) regulates many SGA biosynthesis genes in tomato and potato. Here we report that the expression of a cluster of genes encoding nitrate transporter 1/peptide transporter family (NPF) members is downregulated in the jre4-1 loss-of-function tomato mutant, which has a low-SGA phenotype compared to the wild type. NPFs are a large family of plant membrane transporters that transport a wide range of substrates, including specialized metabolites. We found that the JRE4-regulated NPF genes are induced by the defense-related phytohormone jasmonate. Conversely, jasmonate-mediated induction of gene expression was attenuated by ethylene treatment of the leaves. The co-regulation of the NPF genes with SGA biosynthesis genes by JRE4 suggests that NPF transporters are involved in the SGA pathway. 

Downregulation of a cluster of genes encoding nitrate transporter 1/peptide transporter family proteins in tomato with a mutated JRE4 transcription factor

Complexe egf/egfr

Low-frequency communication is one of the best ways to reduce signal attenuation from the human body, although slow data rates make stable wireless communication within the human body difficult. In this paper, we designed two coil antennas for wireless implant communication, including a small dual-band transmitting antenna that can be placed inside the human body and a corresponding receiving antenna that can be mounted on the abdomen of the human body. The proposed antenna is fed from a battery-powered impulse radio (IR) transceiver peaking at 10–60 MHz, and the antenna is designed to be wideband for higher data communication rate. Simulation and measurement of reflection and transmission coefficients confirmed operation at 40–60 MHz. In addition, a battery-powered IR transceiver is used to measure the transmission performance in a 2/3 muscle phantom. As a result, communication at a data rate of 20 Mbps is achieved at a distance of 90 mm in the 2/3 muscle phantom.

Kazuki Saito

Papers

Multi‐Gene Transformation for Pathway Engineering of Secondary Metabolites

Proteins having a flavonoid 5-O-glycosyltransferase activity (5GT)

Downregulation of a cluster of genes encoding nitrate transporter 1/peptide transporter family proteins in tomato with a mutated JRE4 transcription factor

Complexe egf/egfr

Small Coil Antenna With Magnetic Sheet for Implantable Medical Device Communication in 40–60 MHz Band