Survival of strawberry-pathogenic fungi Fusarium oxysporum f. sp. fragariae, Phytophthora cactorum and Verticillium dahliae under anaerobic conditions

The growth and survival of three strawberry pathogens, Fusarium oxysporum f. sp. fragariae (FOF), Phytophthora cactorum, and Verticillium dahliae, were examined in anaerobic (anoxic) conditions at several temperatures (10–40 °C). The growth and survival of these fungi were suppressed by anaerobic conditions in comparison with those in cultured aerobically. Under anaerobic conditions at 22.5 °C, tested isolates of FOF and P. cactorum grew slightly, but V. dahliae did not grow. The three fungi survive for markedly shorter time in the anaerobic conditions compared with the aerobic conditions at all tested temperatures except 40 °C for FOF and P. cactorum. Moreover, survival periods shortened as the cultivation temperature increased. These results demonstrate that anaerobic conditions contribute to eradicating these pathogens during flooding or reductive soil disinfestation.     

QTLs for phosphorus deficiency tolerance detected in upland NERICA varieties

Phosphorous (P) deficiency is a major yield limiting factor in rice (Oryza sativa L.) production. The interspecific New Rice for Africa (NERICA) varieties combine general stress tolerance from African cultivated rice (Oryza glaberrima Steud) with characteristics associated with high yield from O. sativa. However, little is known about their ability to tolerate P deficiency. Here, we examined the variation for tolerance to P deficiency among the 18 upland NERICAs and their parents in multi‐year field experiments. The good performance under P deficiency of the O. glaberrima parent CG 14 and some NERICAs suggested that these tolerant NERICAs contain loci associated with P deficiency tolerance inherited from CG 14. Additionally, four QTL clusters for P deficiency tolerance were detected on chromosomes 4, 6 and 11 using F₃ lines derived from the cross between the P deficiency tolerant variety NERICA10 and a Japonica‐type sensitive variety ‘Hitomebore’. These QTLs represent the first step in identifying stress tolerance genes from O. glaberrima that could subsequently be used to enhance P deficiency tolerance in O. sativa.     

Creation of long-day adapted tetraploid potatoes from crosses of <Emphasis Type="Italic">Solanum tarijense</Emphasis> females with Andigena males

T-type is a common chloroplast DNA type among modern potato varieties (Solanum tuberosum), their progenitor Chilean tuberosum, and a diploid wild species S. tarijense. To recreate Chilean tuberosum, we made 983 pollinations between 10 accessions of T-type chloroplast DNA-holding S. tarijense used as females and 32 Andean tetraploid landraces (Andigena) used as males, from which 14 tetraploid hybrids were obtained. These interspecific hybrids grew vigorously with long stolons, flowered well with high male and female fertilities, and matured 1 month later than modern varieties. Seedlings of selfed and sib-crossed interspecific hybrids were artificially selected for tuber yield under long days. The selected clones were grown in the field, of which two clones produced over 1 kg of edible tubers per plant. These results lend experimental support to the hypothesis that the Chilean tuberosum originated by selection for long-day adaptability from tetraploid hybrids that occurred by fertilization of a 2n egg of S. tarijense and n pollen of Andigena.     

Development of an enzyme-linked immunosorbent assay (ELISA) for residue analysis of the fungicide azoxystrobin in agricultural products

A direct competitive enzyme-linked immunosorbent assay (dc-ELISA) was developed for residue analysis of azoxystrobin in garden crops, for which the maximum residue limits (MRLs) are 0.5-50 mg/kg in Japan. For hapten synthesis, an ethyl carboxyl group was introduced to the 4-position of the 2-cyanophenoxy group in azoxystrobin, and its cyano group was changed to a methyl group. An anti-azoxystrobin monoclonal antibody was prepared from mice immunized with hapten-keyhole limpet hemocyanin conjugate. The dc-ELISA using prepared antibody showed 50-250-fold higher sensitivity compared to the MRLs. The working range of the dc-ELISA was 10-200 ng/mL. The dc-ELISA showed high specificity to azoxystrobin. When methanol extracts from nine kinds of garden crops spiked with azoxystrobin ranging near the MRLs were analyzed, the determined results by the dc-ELISA agreed well with the results of their controls. In addition, azoxystrobin spiked in garden crops homogenates was satisfactorily extracted by methanol solution and easily analyzed. The recovery rate of dc-ELISA was 96-109% and correlated well with the results obtained by HPLC analysis.     

Induction of Apoptotic Cell Death in Human Leukemia U937 Cells by C18 Hydroxy Unsaturated Fatty Acid Isolated from Red Alga Tricleocarpa jejuensis

Our previous studies have found that (±)-(E)-12-hydroxyoctadec-10-enoic acid (HOEA) isolated from the red alga Tricleocarpa jejuensis showed cytotoxic effects on various living organisms including harmful microalgae, Gram-positive bacteria, and mammalian tumor cells. Since natural products with apoptosis-inducing ability can be promising anti-cancer agents, in this study, we investigated the cytotoxic mechanism of HOEA on U937 cells focusing on apoptosis induction. HOEA showed much stronger cytotoxic and cytolytic effects on U937 cells than elaidic acid, which has similar structure but no 12-hydroxy group, suggesting that hydroxy group is important for the cytotoxicity of HOEA. HOEA induced apoptotic nuclear morphological changes, DNA fragmentation, and decrease in mitochondrial membrane potential. Furthermore, time-dependent increase in annexin V+/PI+ cell population in HOEA-treated U937 cells was detected. Among the apoptosis-related reagents, caspase-family inhibitor almost completely inhibited HOEA-induced DNA fragmentation. In the analyses using specific caspase-substrates, extremely high cleavage activity toward caspase-3/7/8 substrate was observed in HOEA-treated U937 cells, and weak activities of caspase-1 and -3 were detected. Analyses using specific caspase inhibitors suggested that caspase-3 and caspase-8 might be predominantly responsible for the cleavage activity. Activation of these caspases were also confirmed by western blotting in which significant levels of cleaved forms of caspase 3, caspase 8, and PARP were detected in HOEA-treated U937 cells. Our results suggest that HOEA is capable of inducing apoptosis in U937 cells in which caspase-3 and caspase-8 might play important roles. Since the cytotoxic effect of HOEA is not strictly specific to tumor cells, development of appropriate drug delivery system for selective tumor targeting is necessary for the clinical applications to reduce the possible side effects.     

Metabolomic Analyses of Blood Plasma after Oral Administration of D-Glucosamine Hydrochloride to Dogs

D-Glucosamine hydrochloride (GlcN∙HCl) is an endogenous amino monosaccharide synthesized from glucose that is useful in the treatment of joint diseases in both humans and animals. The aim of this study was to examine amino acid metabolism in dogs after oral administration of GlcN∙HCl. Accelerated fumarate respiration and elevated plasma levels of lactic acid and alanine were observed after administration. These results suggest that oral administration of GlcN∙HCl induces anaerobic respiration and starvation in cells, and we hypothesize that these conditions promote cartilage regeneration. Further studies are required to evaluate the expression of transforming growth factor-beta (TGF-β).     

Metabolomic Analysis of Blood Plasma after Oral Administration of N-acetyl-d-Glucosamine in Dogs

N-acetyl-d-glucosamine (GlcNAc) is a monosaccharide that polymerizes linearly through (1,4)-β-linkages. GlcNAc is the monomeric unit of the polymer chitin. GlcNAc is a basic component of hyaluronic acid and keratin sulfate found on the cell surface. The aim of this study was to examine amino acid metabolism after oral GlcNAc administration in dogs. Results showed that plasma levels of ectoine were significantly higher after oral administration of GlcNAc than prior to administration (p < 0.001). To our knowledge, there have been no reports of increased ectoine concentrations in the plasma. The mechanism by which GlcNAc administration leads to increased ectoine plasma concentration remains unclear; future studies are required to clarify this mechanism.     

Identification of alfonsino, Beryx mollis and B. splendens collected in Japan, based on the mitochondrial cytochrome b gene, and their comparison with those collected in New Caledonia

ABSTRACT:   The sequences spanning 307 bp of the mitochondrial cytochrome b gene were determined for 45 sepcimens of Beryx splendens and seven specimens of B. mollis collected in Japan, resulting in identification of 11 and three haplotypes in the two species, respectively. The parsimony tree was constructed from the determined sequences and those registered into the GenBank database as species A and W of B. splendens collected in New Caledonia, featuring with two clades. The first clade comprised species W from New Caledonia and B. mollis in the present study, whereas the second one contained species A from New Caledonia and B. splendens in the present study. These results demonstrate a large geographic distribution for both B. splendens and B. mollis. Some of the haplotypes found in Japan were identical to those of New Caledonia for both B. mollis and B. splendens , suggesting levels of gene flow at the trans -oceanic scale.     

Age and maturation of jack mackerel Trachurus japonicus in the East China Sea

Growth and reproductive characteristics of jack mackerel Trachurus japonicus collected in the East China Sea were determined based on otolith readings and gonad histology, respectively. Translucent and opaque zones on sectioned otoliths were identified and opaque rings counted. Von Bertalanffy growth parameters did not significantly differ between males and females, and the combined growth curve was: L _t  = 401{1 ? exp[?0.275 (t + 1.149)]} (0.8 < t < 6.9), where L _t is fork length (mm) at age t. The calculated lengths at age 1 in our study were larger than those reported 50 years ago from the East China Sea. The spawning period was evaluated to be from December to June, but primarily from February to May, based on the monthly changes in the gonadosomatic index and histological observations. The minimum size and age at first maturity were smaller and younger, respectively, than those reported in previous studies.     

Using a multivariate auto-regressive state-space (MARSS) model to evaluate fishery resources abundance in the East China Sea,based on spatial distributional information

The abundance index (AI) is a representative indicator used to assess the state of fishery resources. Conventional AI is generally calculated by summing the catch per unit of effort (CPUE) weighted by the size of each fishing area. However, CPUE data has many missing values owing to annual changes in operational fishing areas, and this can lead to a considerable bias in the estimated AI. To obtain an unbiased AI, a multivariate auto-regressive state-space (MARSS) model was used to estimate and interpolate missing values in a spatially arranged, long-term bottom-trawl CPUE dataset for yellow seabream Dentex hypselosomus and largehead hairtail Trichiurus japonicus in the East China Sea. As expected, increasing the number of analyzed fishing grids improved interpolation accuracy, but remarkably increased the time required for the analysis. Reducing the maximum number of expectation–maximization (EM) iterations in the maximum likelihood procedure was an effective way to practically reduce analysis time, while keeping the accuracy of the estimation. Thus, this EM-reduction MARSS model was applied to the entire CPUE datasets of yellow seabream and largehead hairtail to address the annual shifts in their AIs and their seasonal migration.