Studies on the magnesium metabolism of crops (Part 1) the balance among magnesium,calcium and pot assLum in free and bound forms at the flowering stage of soy-bean plants

In the later nineteenth century, it was established that magnesium is one of the essential elements to plant life. In 1902 Loew¹⁾ and his pupils suggested the necessity of calcium-magnesium- balance in culture solution for the proper growth of the plant. Then, in 1906, it was established that, as first shown by Willstatter, magnesium is one of the constituents of chlorophyll and when this element is lacking, a chlorosis occurs. Dickson²⁾, in 1918, described about the feature of oat plant grown in a magnesium deficient nutrient solution. At that time, it was thought that magnesium was generally contained in the soil more abundantly than the plant required. So this element scarcely received attention. Garner et al.³⁾, in 1923, observed that chlorosis of tobacco plant, so-called sand drown was cured by applying magnesium to the soil. Similar observation was made in 1929 by Jones⁴⁾ on the chlorosis of corn plant. Since that time the magnesium deficiency in all crops was observed everywhere by a great many investigators. In Japan magnesium deficiency in the field has attracted attention from 1951.     

Carbon skeletons for amide synthesis during ammonium nutrition in tomato and wheat roots

Heavy application of ammonium nitrogen to plant roots results in the conversion of ammonium nitrogen to the nitrogen of amides, glutamine, and asparagine, which are stored in roots or translocated to shoot. Since the net synthesis of such amides requires the supply of corresponding carbon skeletons, the carbon metabolism in amide synthesis in response to ammonium supply was investigated in tomato and wheat roots. The content of major primary amino acids was determined in tomato and wheat roots during a 4-d period of ammonium nutrition after 1-d culture in nitrogen-free nutrient solution. Ammonium supply led to a continuous increase in the asparagine content in wheat roots, whereas in tomato roots, the glutamine content increased 1 d after ammonium supply and thereafter the glutamine content was higher than the asparagine content. The amounts of amino acids synthesized from glucose-¹⁴C increased while the amounts of organic acids decreased in tomato roots by the supply of ammonium nitrogen for 1 d, compared to the roots that did not receive nitrogen. In tomato roots, the proportion of labeled glutamine was higher than that of labeled asparagine and the C5 amino acids were more strongly labeled than the C4 amino acids. These findings were different from the previous ones in wheat roots where the proportion of asparagine was found to be extremely high (Koga and Ikeda 2000: J. Fac. Agr. Kyushu Univ45, 7–13). To examine the in vivo asparagine synthesis, aspartate-'4C was fed to the roots. The labeling of asparagine, which was the most strongly labeled amino acid among the free amino acids, was remarkably strong in wheat roots whereas the labeling of glutamine was also pronounced in tomato roots. These results indicate that the ability to replenish carbon skeletons for amide synthesis in ammonium nutrition is different between tomato and wheat roots.     

Novel capsid genes (g23) of T4-type bacteriophages in a Japanese paddy field

Viruses exist everywhere on the planet. Recent development in viral genomics confirmed that genomic information is preserved among viral subsets and can be used for phylogenetic classification of viruses and for evaluation of viral diversity in the environment. The capsid gene of T4-type bacteriophages, g23, is the most widely applied gene for evaluating the diversity of the T4-type bacteriophage family. In this study, we applied denaturing gradient gel electrophoresis to PCR products of DNA with g23-specific primers that were extracted from a Japanese paddy field under long-term fertilizer trial and obtained 39 different g23 clones at the DNA level. They showed identities of 27–99% with the clones within the NCBI database at the amino acid level. They were quite distinctive from those obtained in marine environments and most of them formed six phylogenetically novel groups in the T4-type bacteriophage family with the clones obtained from another paddy field. The existence of six novel groups was confirmed from molecular analysis of all the amino acid sequences between the primers, of the amino acid sequences excluding hypervariable region, and of those of conserved regions. These findings indicate that T4-type bacteriophage communities in paddy fields consist of previously uncharacterized members phylogenetically distant from those in marine environments. The type of fertilizers and the stage during rice cultivation were not the major factors in determining T4-type bacteriophage communities in the paddy field.     

Effects of Ozone and/or Excess Soil Nitrogen on Growth, Needle Gas Exchange Rates and Rubisco Contents of Pinus Densiflora Seedlings

The effects of ozone (O₃) and excess soil nitrogen (N), singly and in combination, on growth, needle gas exchange rates and ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) contents of Pinus densiflora seedlings were investigated. One-year-old seedlings were grown in 1.5-L pots filled with brown forest soil with 3 levels of N supply (0, 100 or 300 mg N·L^?1 fresh soil volume). The seedlings were exposed to charcoal-filtered air or 60±5 nL·L^?1 O₃ (8 hours a day) in naturally-lit phytotrons for 173 days from 22 May to 11 November. The exposure to O₃ or high N supply to the soil caused a significant reduction in the dry weights of the seedlings. Although no significant interactive effects of O₃ and excess soil N were detected on the dry weight growth of the seedlings, the whole-plant dry weight of the O₃-exposed seedlings grown in the soil treated with 300 mg N·L^?1 was greatly reduced compared with the control value. Ozone reduced net photosynthetic rate at 350 µmol·mol^?1 CO₂ (A ₃₅₀ ), carboxylation efficiency (CE) of photosynthesis and Rubisco content without a significant change in the gaseous phase diffusive conductance to CO₂ (gs) of the needles. The excess soil N reduced the A ₃₅₀ , CE, gs and Rubisco content of the needles. These results suggest that the reduction in the dry weight growth of Pinus densiflora seedlings induced by the exposure to O₃ and/or excess soil N was caused by reduction in the net photosynthetic rate mainly due to the decrease of Rubisco quantity in the chloroplasts.     

A genome‐wide association study for fat‐related traits computed by image analysis in Japanese Black cattle

The objective of this study was to identify genomic regions associated with fat‐related traits using a Japanese Black cattle population in Hyogo. From 1836 animals, those with high or low values were selected on the basis of corrected phenotype and then pooled into high and low groups (n = 100 each), respectively. DNA pool‐based genome‐wide association study (GWAS) was performed using Illumina BovineSNP50 BeadChip v2 with three replicate assays for each pooled sample. GWAS detected that two single nucleotide polymorphisms (SNPs) on BTA7 (ARS‐BFGL‐NGS‐35463 and Hapmap23838‐BTA‐163815) and one SNP on BTA12 (ARS‐BFGL‐NGS‐2915) significantly affected fat percentage (FAR). The significance of ARS‐BFGL‐NGS‐35463 on BTA7 was confirmed by individual genotyping in all pooled samples. Moreover, association analysis between SNP and FAR in 803 Japanese Black cattle revealed a significant effect of SNP on FAR. Thus, further investigation of these regions is required to identify FAR‐associated genes and mutations, which can lead to the development of DNA markers for marker‐assisted selection for the genetic improvement of beef quality.     

Effect of Inositol Hexaphosphate (IP6) on Serum Uric Acid in Hyperuricemic Subjects: a Randomized,Double-Blind,Placebo-Controlled,Crossover Study

Plant Foods for Human Nutrition - Inositol hexaphosphate (IP6), a food constituent with various health benefits, has been shown to suppress postprandial elevations of serum uric acid (SUA) levels...     

Monitoring of chronic wasting disease using real-time quaking-induced conversion assay in Japan

There has been no report on Chronic wasting disease (CWD) cases in Japan to date; however, there is concern about the geographic spread of CWD. To clarify the CWD status in Japan, we conducted CWD monitoring using real-time quaking-induced conversion (RT-QuIC) assay which can detect the low level of CWD prions. A total of 690 obex samples collected from sika deer and Reeves’s muntjac in Hokkaido and Honshu was tested for CWD prions. No CWD-positive cases were found, suggesting that CWD is nonexistent in Japan. Our results also indicate that RT-QuIC assay is useful for continuous monitoring of CWD. Furthermore, nucleotide sequence analysis of the PrP gene revealed sika deer in Japan harbor CWD susceptible allele.     

Serodiagnosis of Neospora caninum infection in cattle by enzyme-linked immunosorbent assay with recombinant truncated NcSAG1

Neospora caninum is a veterinary medically important pathogen capable of causing abortion in cattle and neuromuscular paralysis in dogs. The surface antigen 1 of N. caninum (NcSAG1) is an important candidate for the development of a diagnostic reagent for neosporosis. In order to establish an effective diagnostic method, the gene encoding truncated NcSAG1 (NcSAG1t) lacking a signal peptide and C-terminal hydrophobic regions was cloned and expressed in Escherichia coli as a fusion protein with glutathione S-transferase (GST). The purified GST-NcSAG1t was tested in an enzyme-linked immunosorbent assay (ELISA) for the detection of N. caninum antibodies in cattle. The ELISA with GST-NcSAG1t clearly differentiated between immunofluorescent antibody test (IFAT)-positive and -negative sera from cattle. In addition, the ELISA detected no cross-reactivity with sera from mice experimentally infected with the closely related parasite Toxoplasma gondii. Field serum samples collected from cattle in Brazil were examined for the diagnosis of neosporosis by using the ELISA. Of the 197 samples analyzed, 66 (33.5%) samples were positive for antibodies to N. caninum. Of the 66 ELISA-positive samples, 60 (90%) samples were confirmed as positive by Western blot analysis with whole parasite antigens. These results suggest that the recombinant NcSAG1t could be a reliable reagent for use as an antigen in ELISA for the serodiagnosis of N. caninum infection in cattle.     

波流作用下网格锚泊的单个重力式网箱缆绳张力

以中国沿海常用的周长40 m×10 m的HDPE重力式网箱作为研究对象,采用渔具模型试验狄克生准则,选用大比例尺(λ=1/10)和小比例尺(λ′＝ 1/2)设计制作模型网箱.网箱锚泊系统采用的网格形式与实际使用的一致.模型试验于日本东京大学生产技术研究所海洋环境工程实验室风浪流水槽[50 m(L)×10 m(W)×5 ...     

Effects of Environmental Temperature on Structure and Gelatinization Properties of Wheat Starch

The effects of environmental temperature on gelatinization properties and amylopectin structures of wheat endosperm starch were examined by isolating starches from four wheat cultivars matured in growth chambers at daytime temperatures of 15, 20, 25, or 30°C. Kernel weight and starch content per kernel were reduced by high maturation temperature. Amylose content showed no significant change at high maturation temperature in some cultivars; in other cultivars, there was a slight increase. Principal component analysis of data on relative peak areas of debranched amylopectin showed that amylopectin from wheat grown at a lower temperature had a greater proportion of shorter chains. Amylopectin branch chains were classified into three groups based on the correlation coefficients between the data of branch chain length distribution and principal component scores, degree of polymerization (DP) of 6–12, DP 13–34, and DP ≥ 35. The gelatinization temperature of starches increased markedly at a higher maturation temperature, with increases exceeding 10°C at high maturation temperatures. Gelatinization properties correlated significantly with amylopectin chain length distribution.