Detection of calmodulin and calmodulin-binding proteins in pure phloem sap of rice plants     

Shin-ichi NAKAMURA  Hiroaki HAYASHI  Mitsuo CHINO 《Soil Science and Plant Nutrition》2006,52(2):195-202

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Metabolism of furametpyr. 2. (14)C excretion, (14)C concentrations in tissues, and amounts of metabolites in rats     

Nagahori H  Yoshino H  Tomigahara Y  Isobe N  Kaneko H  Nakatsuka I 《Journal of agricultural and food chemistry》2000,48(11):5760-5767

14C-Labeled furametpyr [N-(1,3-dihydro-1,1, 3-trimethylisobenzofuran-4-yl)-5-chloro-1, 3-dimethylpyrazole-4-carboxamide, Limber] was dosed to male and female rats at 1 (low dose) and 200 or 300 mg/kg (high dose). Elimination of furametpyr was rapid, and the dosed (14)C was substantially excreted within 7 days (45.5-53.3% in feces, 44.1-53. 8% in urine, and 0.01% in expired air). However, (14)C excretion rate showed sex- and dose-related differences, more rapid in males at low dose. (14)C concentrations in tissues decreased rapidly to generally low levels at 7 days (<0.004 ppm with the low dose and <1. 1 ppm with the high dose). Forty metabolites were detected, and 13 metabolites and 4 glucuronides were identified. A small amount of unchanged furametpyr was detected in feces (0.1-0.5% of the dose). The major metabolites in tissues were N-demethylated metabolites. In a bile study, 52.5-54.2% of the dosed (14)C was rapidly excreted into bile within 2 days. The absorption ratio was estimated to be >93.7% for the low dose (1 mg/kg). Major metabolites in bile were glucuronic acid conjugates of furametpyr hydroxides. On the basis of the results, furametpyr is substantially absorbed from the gastrointestinal tract after oral administration, rapidly distributed to tissues, extensively metabolized, and excreted into urine and bile or feces.  相似文献   

Early-stage impacts of sika deer on structure and function of the soil microbial food webs in a temperate forest: A large-scale experiment     

Shigeru Niwa  Lucero MarianiNobuhiro Kaneko  Hiroaki OkadaKazunori Sakamoto 《Forest Ecology and Management》2011,261(3):391-399

Modification of forest vegetation caused by an overabundance of mammalian herbivores has been reported in temperate and subarctic regions all over the world. However, the indirect effects of these herbivores on the structure and functions of soil decomposer systems are not fully understood, especially in temperate forests. We investigated the early effects of sika deer invasion on soil decomposer systems in a Japanese temperate forest using two large-scale experimental enclosures with low and high densities of deer (LD: 25 ha, 4 deer km⁻²; HD: 6.25 ha, 16 deer km⁻²) including control plots without deer (WD). Three years after deer introduction the understory cover of dwarf bamboo (Sasa nipponica) declined due to deer browsing in both enclosures. At the same time, measurements were made of the soil microbial community, soil nematode community, soil nitrogen (N) mineralization rate, and carbon (C) and N content in dwarf bamboo leaves. In LD, soil microbial biomass was lower from WD, probably due to the decrease of fresh aboveground litter from dwarf bamboo. Surprisingly, there were no cascading effects on total abundance of soil nematodes and soil total N mineralization potential which were unaffected by deer in the LD treatment, while soil NH₄⁺-N content was lower and soil nematode community structure was different (abundance of 4 families was higher and that of 3 families was lower, but the functional structure was not different) from WD. Specifically, the responses to deer introduction varied between microbes and nematodes, and the change of balance in the microbial food webs may have altered N mineralization processes. In contrast, in the HD treatment, all the variables measured were not significantly different from those of WD treatment. Intensive browsing by deer may have cancelled out the effects of the decrease in aboveground litter input on the soil decomposer systems through other pathways, such as a transitory increase in belowground litter input caused by induced changes in allocation patterns of bamboo. No changes in total N mineralization potential, leaf N, and composition of understory vegetation in both enclosures indicated that deer introduction did not facilitate nor retard N cycling regardless of deer density. This study showed that sika deer browsing can affect soil decomposer systems at an early stage of invasion even at low density, which contrasts with previous studies on the subject. Linking our findings of early-stage effects of deer on soil decomposer systems to longer-term dynamics of understory vegetation and tree regeneration will be needed to evaluate the adequacy of deer management practices with respect to the sustainability of soil nutrient supplies.  相似文献   

Fine-root dynamics in a young hinoki cypress (<Emphasis Type="Italic">Chamaecyparis obtusa</Emphasis>) stand for 3 years following thinning     

Kyotaro Noguchi  Qingmin Han  Masatake G. Araki  Tatsuro Kawasaki  Shinji Kaneko  Masamichi Takahashi  Yukihiro Chiba 《Journal of Forest Research》2011,16(4):284-291

Fine roots play a key role in carbon and nutrient dynamics in forested ecosystems. Fine-root dynamics can be significantly affected by forest management practices such as thinning, but research on this topic is limited. This study examined dynamics of fine roots <1 mm in diameter in a 10-year-old stand of hinoki cypress (Chamaecyparis obtusa) for 3 years following thinning (65% in basal area). Fine-root production and mortality rates were estimated using a minirhizotron technique in combination with soil coring. In both thinned and un-thinned control plots, fine-root elongation occurred from early spring to winter (March to December) and fluctuated seasonally. In the thinned and the control plots, the annual fine-root production rates were estimated to be 101 and 120 g m⁻² year⁻¹, respectively, whereas the estimated annual fine-root mortality rates were 77 and 69 g m⁻² year⁻¹, respectively. At 3 years after thinning, live fine-root biomass was significantly smaller in the thinned plot (143 g m⁻²) than in the control plot (218 g m⁻²), whereas dead fine-root biomass was not (147 and 103 g m⁻², respectively). Morphological and physiological indices of fine roots such as diameter, specific root length, and root tissue density of the live fine roots was similar in both plots. These results suggested that thinning tended to decrease biomass and production of fine roots, but the effects on characteristics of fine roots would be less evident.  相似文献   

KT-30和GA ₃ 对美味猕猴桃座果及果实发育的影响     

赵梁军  白石真一  若菜章 《中国农业大学学报》1995,(Z1):17-22

观察了KT-30与GA_3处理对美味猕猴桃座果、果实发育和品质形成的影响。开花期分别用KT-3040mg·L~(-1)和GA_3500mg·L~(-1)处理花蕾可诱导单性结实;花后20d用KT-3010mg·L~(-1)处理幼果可明显促进果实生长、提高果实中淀粉和糖含量,但降低果实硬度和钙含量且果实外观品质较差。开花后2周用KT-305mg·L~(-1)与GA_3200mg·L~(-1)的混合液处理幼果,可促进果实生长,提高果实硬度,不降低果实外观品质,处理效果最佳。  相似文献   

Occurrence and characterization of tomato spotted wilt orthotospovirus isolated from cucumber     

Kon  Tatsuya  Watanabe  Noriko  Ootake  Hironori  Fuji  Shin-ichi 《European journal of plant pathology / European Foundation for Plant Pathology》2022,163(4):789-797

European Journal of Plant Pathology - Diseases associated with tomato spotted wilt orthotospovirus (TSWV) are a serious threat to vegetable production worldwide. In 2019, leaf necrosis disease was...  相似文献   

Effects of fine-scale simulation of deer browsing on soil micro-foodweb structure and N mineralization rate in a temperate forest     

Shigeru Niwa  Nobuhiro Kaneko  Hiroaki Okada  Kazunori Sakamoto 《Soil biology & biochemistry》2008,40(3):699-708

The effects of low densities of native browsing mammals on nutrient cycling are not fully understood. Weak browsing may improve nitrogen (N) mineralization in soil and positively affect plant regrowth at the forest floor. To investigate the effects of weak browsing by sika deer (Cervus nippon) on soil subsystems, we defoliated a dwarf bamboo (Sasa nipponica)-dominated understory layer in a natural forest at different intensities to realistically simulate deer browsing. Defoliation (0–18% leaf removal) was performed three times at approximately 1-week intervals in summer. We measured water-soluble carbon (C) concentration, phospholipid fatty acid (PLFA) profiles as indicators of microbial community structure, a PLFA of 20:4 as an indicator of protozoan abundance, nematode community structure at the family level, and the N mineralization rate in 28 days of incubation. The effects of defoliation on each soil parameter were determined by comparing before and after defoliation values. The N mineralization rate in the first 10 days of incubation showed a unimodal response to defoliation intensity, with a peak mineralization rate at a defoliation rate (number of removed leaves/total leaves) of 7.6%, correlating with protozoan PLFA and the abundance of Plectidae (the most dominant family of bacterivorous nematodes). In contrast, the N mineralization rate during the following 18 days of incubation decreased monotonically with increasing defoliation intensity, correlating with the water-soluble C concentration in the soil and the C content of new leaves. These results suggest that removing <15% of leaves may have induced a pulse-like release of labile organic matter from roots that lasted for less than 1 week and stimulated N mineralization through microbial loop in soil in the short term (in the first 1–2 weeks after defoliation). N mineralization, however, was reduced with increase of defoliation intensity in the longer term (3–5 weeks after defoliation), possibly because of the reduction in labile organic matter supply from roots 1 week after defoliation. As a result, N mineralization rates over the 28-day incubation period responded to defoliation intensity in a unimodal pattern with a small peak (at a defoliation rate of 4.9%) and were negatively affected by high defoliation rates (>10%). This study suggests that browsing on forest floor plants has positive or negative effects on soil N mineralization potential depending on browsing intensity level.  相似文献   

Anti-inflammatory activity of immunoglobulin G resulting from Fc sialylation     

Kaneko Y  Nimmerjahn F  Ravetch JV 《Science (New York, N.Y.)》2006,313(5787):670-673

Immunoglobulin G (IgG) mediates pro- and anti-inflammatory activities through the engagement of its Fc fragment (Fc) with distinct Fcg receptors (FcgRs). One class of Fc-FcgR interactions generates pro-inflammatory effects of immune complexes and cytotoxic antibodies. In contrast, therapeutic intravenous gamma globulin and its Fc fragments are anti-inflammatory. We show here that these distinct properties of the IgG Fc result from differential sialylation of the Fc core polysaccharide. IgG acquires anti-inflammatory properties upon Fc sialylation, which is reduced upon the induction of an antigen-specific immune response. This differential sialylation may provide a switch from innate anti-inflammatory activity in the steady state to generating adaptive pro-inflammatory effects upon antigenic challenge.  相似文献   

Neuronal pathway from the liver modulates energy expenditure and systemic insulin sensitivity     

Uno K  Katagiri H  Yamada T  Ishigaki Y  Ogihara T  Imai J  Hasegawa Y  Gao J  Kaneko K  Iwasaki H  Ishihara H  Sasano H  Inukai K  Mizuguchi H  Asano T  Shiota M  Nakazato M  Oka Y 《Science (New York, N.Y.)》2006,312(5780):1656-1659

Coordinated control of energy metabolism and glucose homeostasis requires communication between organs and tissues. We identified a neuronal pathway that participates in the cross talk between the liver and adipose tissue. By studying a mouse model, we showed that adenovirus-mediated expression of peroxisome proliferator-activated receptor (PPAR)-g2 in the liver induces acute hepatic steatosis while markedly decreasing peripheral adiposity. These changes were accompanied by increased energy expenditure and improved systemic insulin sensitivity. Hepatic vagotomy and selective afferent blockage of the hepatic vagus revealed that the effects on peripheral tissues involve the afferent vagal nerve. Furthermore, an antidiabetic thiazolidinedione, a PPARg agonist, enhanced this pathway. This neuronal pathway from the liver may function to protect against metabolic perturbation induced by excessive energy storage.  相似文献   

Expression and localization of tight junction-related proteins in adult rat pituitary stem/progenitor cell niches     

Saishu YOSHIDA  Hideaki YURINO  Masaaki KOBAYASHI  Naoto NISHIMURA  Kentaro YANO  Ken FUJIWARA  Shin-ichi HASHIMOTO  Takako KATO  Yukio KATO 《The Journal of reproduction and development》2022,68(3):225

Pituitary endocrine cells are supplied by Sox2-expressing stem/progenitor cells in the anterior lobe of the adult pituitary gland. These SOX2-positive cells are maintained in two types of microenvironments (niches): the marginal cell layer (MCL)-niche and the parenchymal-niche. Recently, we isolated dense SOX2-positive cell clusters from the parenchymal-niche by taking advantage of their resistance to protease treatment as parenchymal stem/progenitor cell (PS)-clusters. In the present study, by analyzing these isolated PS-clusters, we attempted to identify novel structural characteristics of pituitary stem/progenitor cell niches. Quantitative real-time PCR showed that tight junction-related genes were distinctly expressed in the isolated PS-clusters. Immunocytostaining showed that the tight junction molecules, ZO-1 and occludin, were localized in the apical membrane facing the pseudo-follicle-like structure of the isolated PS-clusters regardless of the expression of S100β, which distinguishes the sub-population of SOX2-positive cells. Furthermore, immunohistochemistry of the pituitary glands of adult rats clearly demonstrated that ZO-1 and occludin were densely present in the parenchymal-niche encircling the pseudo-follicle, while they were observed in the apical membrane in the MCL-niche facing the residual lumen. Collectively, these tight junction-related proteins might be involved in the architecture and maintenance of the plasticity of pituitary stem/progenitor cell niches.  相似文献