Identification of Cylindrocladium sp. causing damping-off disease of Japanese black pine (Pinus thunbergii) and factors affecting the disease severity in a black locust (Robinia pseudoacacia)-dominated area

The regeneration of Japanese black pine (Pinus thunbergii) seedlings is inhibited in a black locust (Robinia pseudoacacia)-dominated area. We examined the presence of pathogenic fungi in Japanese black pine seedlings in the area in order to determine the effect of pathogenic fungi on the inhibition of regeneration. When Japanese black pine seedlings were planted in the soil obtained from a black locust-dominated area, all of the seedlings died under low-intensity light conditions, whereas 84% of the seedlings survived in the soil obtained from a Japanese black pine-dominated area under the same light conditions. One fungus was isolated from 48.7% of the dead pine seedlings and was identified as Cylindrocladium pacificum Kang, Crous & Schoch, based on the morphological characteristics, growth, and DNA analysis. This fungus was also isolated from 50% of the dead pine seedlings in 2005 and 66.7% of the seedlings in 2006—both were planted in a black locust-dominated area. The virulence of this fungus increased under high-nitrogen and/or low-intensity light conditions. These results reveal the possibility that the soil eutrophication and shading by the black locust are conducive to a severe damping-off disease and threaten the survival and regeneration of Japanese black pine seedlings.     

Plasma concentrations and effects of glucagon-like peptide-1 (7-36) amide in calves before and after weaning

Glucagon-like peptide-1 (7-36) amide (GLP-1), secreted by the small intestine, has insulinotropic and glucose-lowering action. Basal plasma GLP-1 concentrations were measured in calves around the weaning period, the effect of short-chain fatty acids (SCFA) on plasma GLP-1 concentrations was examined, and the effects of GLP-1 administration on plasma insulin, glucagon, and glucose concentrations were measured. Thirteen Holstein bull calves were fed whole milk and solid feed and weaned at 7 wk of age. Preprandial plasma samples were obtained from 5 calves once a week from week 0 to 13 to measure basal concentrations of plasma GLP-1 and insulin (experiment 1). Four calves were intravenously administered with a mixed solution of SCFA (2.4 mmol/kg body weight [BW]) in week 2 and 11 to measure plasma GLP-1 concentrations (experiment 2). Another 4 calves were intravenously injected with GLP-1 (1.0 μg/kg BW) to elucidate the response of plasma insulin, glucagon, and glucose concentrations in week 1, 2, 4, 6, 7, 9, 11, and 13 (experiment 3). In experiment 1, age and weaning did not affect preprandial basal concentrations of plasma GLP-1 throughout the experimental period. Preprandial insulin concentrations increased after weaning (P < 0.05), and GLP-1 and insulin were more strongly correlated postweaning than preweaning. In experiment 2, intravenous treatment with SCFA increased plasma GLP-1 concentrations in both week 2 and 11 (P < 0.05.) In experiment 3, intravenous GLP-1 treatment decreased plasma glucose concentrations throughout the experiment (P < 0.05), but increased plasma insulin concentrations only after weaning (P < 0.05). Treatment with GLP-1 did not affect plasma glucagon concentrations, regardless of age. These results indicate that preprandial basal concentrations of plasma GLP-1 in calves are not changed by weaning, but SCFA stimulate GLP-1 secretion. The insulinotropic action of GLP-1 is detected only after weaning, but the glucose-lowering action of GLP-1 is not affected by weaning.     

The effects of nitrogen uptake before and after heading on grain protein content and the occurrence of basal- and back-white grains in rice (Oryza sativa L.)

Chalky rice (Oryza sativa L.) grains are induced by high temperature during the grain-filling period. Plant nitrogen status also affects the occurrence of basal- and back-white grains (BBWG). The objective of this study was to elucidate the relations between nitrogen availability per spikelet during the grain-filling period (N_GF) and each of the percentage of BBWG and grain protein content (GPC). We further compared the effect of the components of N_GF determined before heading (N_BH) and after heading (N_AH) on BBWG and GPC. We grew the rice cultivar ‘Koshihikari’ in pots in 2012 and 2013, and top-dressed nitrogen at the panicle formation and heading stages, under two (2012) or three (2013) temperature regimes during the grain-filling period. GPC was explained well by N_GF, but BBWG was not. BBWG was best explained in a multiple-regression equation by mean air temperature after heading and by N_BH and N_AH. The partial correlation coefficients for N_BH were 1.6 and 3.0 times those for N_AH in 2012 and 2013, respectively. On the other hand, in a multiple-regression equation for GPC, the partial correlation coefficients for N_BH were 0.91 and 0.71 times those for N_AH in 2012 and 2013, respectively. These results suggest that rice grains are most sensitive to plant nitrogen status before heading for BBWG but after heading for GPC, and that there is an optimal timing for nitrogen top-dressing that would maximize the reduction in BBWG per unit increment of GPC.     

Iron-deficiency response and expression of genes related to iron homeostasis in poplars

Iron (Fe) deficiency is a serious agricultural problem, especially in calcareous soils, which are distributed worldwide. Poplar trees are an important biomass plant, and overcoming Fe deficiency in poplars will increase biomass productivity worldwide. The poplar Fe-deficiency response and the genes involved in poplar Fe homeostasis remain largely unknown. To identify these genes and processes, we cultivated poplar plants under Fe-deficient conditions, both in calcareous soil and hydroponically, and analyzed their growth rates, leaf Soil and Plant Analyzer Development (SPAD) values, and metal concentrations. The data clearly showed that poplars have notable growth defects in both calcareous soil and a Fe-deficient hydroponic culture. They exhibited serious chlorosis of young leaves after 3 weeks of Fe-deficient hydroponic culture. The Fe concentrations in old leaves with high SPAD values were markedly lower in Fe-deficient poplars, suggesting that poplars may have good translocation capability from old to new leaves. The Zn concentration in new leaves increased in Fe-deficient poplars. The pH of the hydroponic solution decreased in the Fe-deficient culture compared to the Fe-sufficient culture. This finding shows that poplars may be able to adjust the pH of a culture solution to better take up Fe. We also analyzed the expression of Fe homeostasis-related genes in the roots and leaves of Fe-sufficient and Fe-deficient poplars. Our results demonstrate that PtIRT1, PtNAS2, PtFRO2, PtFRO5, and PtFIT were induced in Fe-deficient roots. PtYSL2 and PtNAS4 were induced in Fe-deficient leaves. PtYSL3 was induced in both Fe-deficient leaves and roots. These genes may be involved in the Fe uptake and/or translocation mechanisms in poplars under Fe-deficient conditions. Our results will increase a better understanding of the Fe-deficiency response of poplars and hence improve the breeding of Fe-deficiency-tolerant poplars for improved biomass production, the greening of high pH soils, and combatting global warming.     

Investigation of Soft Wheat Flour Quality Factors Associated with Sponge Cake Sensory Tenderness

Relationships among soft wheat quality parameters relating to sponge cake volume and sensory tenderness were investigated. Sixteen soft wheats from the 2008–2009 crop and 11 from the 2009–2010 crop, including Japanese soft wheat cultivars, advanced breeders' lines, and western white wheat imported from the United States, were milled and evaluated for protein content, sucrose solvent retention capacity value, specific surface area, flour pasting properties, batter pasting viscosity, sodium dodecyl sulfate sedimentation (SDSS) volume, farinograph properties, specific cake volume, and sensory tenderness score to investigate their relationships. Batter pasting viscosity was measured with a Rapid Visco Analyzer (RVA) at 2 min after reaching 90°C in heating a mixture with equal weights of flour, sucrose, and water. RVA minimum viscosity of flour suspension in water was the most influencing factor and positively correlated to specific cake volume, and RVA batter pasting viscosity and SDSS volume were negatively correlated. Meanwhile, protein content and SDSS volume were strongly negatively correlated with sensory tenderness score. Stepwise multiple regression analysis selected protein content and specific cake volume as independent variables to predict sensory tenderness score; however, SDSS volume and farinograph properties relating to protein strength were not selected. Protein content affected sponge cake tenderness independently of specific cake volume, which was related to differences in cake density.     

Effects of duration of electric pulse on in vitro development of cloned cat embryos with human artificial chromosome vector

The current applications for cat cloning include production of models for the study of human and animal diseases. This study was conducted to investigate the optimal fusion protocol on in vitro development of transgenic cloned cat embryos by comparing duration of electric pulse. Cat fibroblast cells containing a human artificial chromosome (HAC) vector were used as genetically modified nuclear donor cells. Couplets were fused and activated simultaneously with a single DC pulse of 3.0 kV/cm for either 30 or 60 μs. Low rates of fusion and embryo development to the blastocyst stage were observed in the reconstructed HAC‐transchromosomic embryos, when the duration of fusion was prolonged to 60 μs. In contrast, the prolongation of electric pulse duration improved the embryo development and quality in the reconstructed control embryos without HAC vector. Our results suggested that the optimal parameters of electric pulses for fusion in cat somatic cell nuclear transfer vary among the types used for donor cells.     

Effects of (−)‐Epigallocatechin Gallate on the Motility and Penetrability of Frozen–Thawed Boar Spermatozoa Incubated in the Fertilization Medium

Epigallocatechin gallate (EGCG) is the major polyphenol in green tea (Camellia sinensis) and is known for its antioxidant effects. The objective of the present study was to examine the effects of EGCG during in vitro fertilization (IVF) on the sperm quality and penetrability into oocytes. In the first experiment, the effects of concentration and incubation period of EGCG on the motility and penetrability of spermatozoa were examined. When frozen–thawed spermatozoa were incubated in IVF medium supplemented with 0 (control), 1, 50 and 100 μm EGCG for 1, 3 and 5 h, supplementation with 50 and 100 μm EGCG improved motility of the spermatozoa (p < 0.05), but not viability, as compared with the control group. When frozen–thawed spermatozoa were co‐incubated with in vitro‐matured (IVM) oocytes in IVF medium supplemented with 50 and 100 μm EGCG for 5 h, supplementation of EGCG had positive effects on sperm penetration rates. In the second experiment, the effects of supplementation of EGCG in IVF medium on penetrability of sperm from different boars and development of fertilized oocytes were evaluated. When frozen–thawed spermatozoa from six boars were co‐incubated with IVM oocytes in IVF medium supplemented with 50 μm EGCG, the effect of EGCG on sperm penetration and development of oocytes after fertilization was found to vary with individual boar. Our results indicate that motility and penetrability of boar spermatozoa are improved by co‐incubation with 50 μm EGCG, but the effects vary with individual boars.     

Ingestion of medium chain fatty acids by lactating dairy cows increases concentrations of plasma ghrelin

The purpose of this study was to elucidate the effects of medium-chain fatty acids (MCFAs) on plasma ghrelin concentration in lactating dairy cows. Five early-lactating Holstein cows were randomly assigned to 2 dietary treatments in a crossover design with 2-wk periods. Treatments consisted of diets supplemented or not (control) with calcium salts of MCFAs (MCFA-Ca; 1.5% dry matter). Plasma hormone and metabolite concentrations in blood samples taken from the jugular vein were measured on the morning of feeding on day 14 of each period. Dry matter intake, milk protein, and lactose content of cows fed the MCFA-Ca diet were decreased compared with controls, but with no change in milk yield. Plasma ghrelin concentrations were higher in cows fed the MCFA-Ca diet; however, no significant effect was found on glucagon-like peptide-1 concentrations in plasma. Plasma insulin concentrations decreased, but plasma glucagon concentrations remained unchanged in cows fed the MCFA-Ca diet. The concentrations of nonesterified FAs, total cholesterol, and β-hydroxybutyrate in plasma increased in these cows. In conclusion, dietary MCFAs increase the plasma ghrelin concentrations in lactating dairy cows.