Virtual screening identifies a novel piperazine-based insect juvenile hormone agonist     

Taiyo Yokoi  Taku Nabe  Shinri Horoiwa  Ken&#x;ichiro Hayashi  Sayoko Ito-Harashima  Takashi Yagi  Yoshiaki Nakagawa  Hisashi Miyagawa 《Journal of Pesticide Science》2021,46(1):68

Juvenile hormone (JH) agonists constitute a subclass of insect growth regulators and play important roles in insect pest management. In this work, a multi-step virtual screening program was executed to find novel JH agonists. A database of 5 million purchasable compounds was sequentially processed with three computational filters: (i) shape and chemical similarity as compared to known JH-active compounds; (ii) molecular docking simulations against a Drosophila JH receptor, methoprene-tolerant; and (iii) free energy calculation of ligand–receptor binding using a modified MM/PBSA (molecular mechanics/Poisson–Boltzmann surface area) protocol. The 11 candidates that passed the three filters were evaluated in a luciferase reporter assay, leading to the identification of a hit compound that contains a piperazine ring system (EC₅₀=870 nM). This compound is structurally dissimilar to known JH agonists and synthetically easy to access; therefore, it is a promising starting point for further structure optimization.  相似文献   

Post-mortem changes in gene expression of the muscle tissue of rainbow trout, Oncorhynchus mykiss     

Saito M  Higuchi T  Suzuki H  Yagi Y  Kunisaki N  Kimura S 《Journal of agricultural and food chemistry》2006,54(25):9417-9421

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DNA marker for resistance to Puccinia horiana in chrysanthemum (Chrysanthemum morifolium Ramat.) “Southern Pegasus”     

Katsuhiko Sumitomo  Kenta Shirasawa  Sachiko N. Isobe  Hideki Hirakawa  Akiho Harata  Masato Kawabe  Masafumi Yagi  Masaaki Osaka  Miyuki Kunihisa  Fumiya Taniguchi 《Breeding Science》2021,71(2):261

White rust caused by Puccinia horiana Henn. adversely affects chrysanthemum (Chrysanthemum morifolium Ramat.) production. The breeding of resistant varieties is effective in controlling the disease. Here we aimed to develop DNA markers for the strong resistance to P. horiana. We conducted a linkage analysis based on the genome-wide association study (GWAS) method. We employed a biparental population for the GWAS, wherein the single nucleotide polymorphism (SNP) allele frequency could be predicted. The population was derived from crosses between a strong resistant “Southern Pegasus” and a susceptible line. The GWAS used simplex and double-simplex SNP markers selected out of SNP candidates mined from ddRAD-Seq data of an F₁ biparental population. These F₁ individuals segregated in a 1:1 ratio of resistant to susceptible. Twenty-one simplex SNPs were significantly associated with P. horiana resistance in “Southern Pegasus” and generated one linkage group. These results show the presence of a single resistance gene in “Southern Pegasus”. We identified the nearest SNP marker located 2.2 cM from P. horiana resistance locus and demonstrated this SNP marker-resistance link using an independent population. This is the first report of an effective DNA marker linked to a gene for P. horiana resistance in chrysanthemum.  相似文献   

Regional Distribution of Natural Stream Nitrate in Central Japan     

Muneoki Yoh  Eiichi Konohira  Kazuyuki Yagi 《Water, air, and soil pollution》2001,130(1-4):655-660

Over 60 natural streams with forested catchments were surveyed for nitrate (NO₃ ^?) concentration in central Japan. Stream NO₃ ^? concentrations showed a clear zonal gradient with a range nearly as large as 100-fold, where their small seasonal variations (av. CV = 27%) justified respective statuses. Elevated NO₃ ^? concentrations (more than 70 µM) described a distribution of N saturation along a course of polluted air advection in the Kanto Plain. The extent of NO₃ ^? leaching from forests was not proportional to atmospheric N deposition probably because of ecosystem N retention. A dependency of NO₃ ^? level on the watershed altitude and quite constant δ¹⁵N of stream NO₃ ^? over a wide NO₃ ^? range were observed, which could be also related to this cause.  相似文献   

Acidification of Growing Cloud Droplet by Rainout of SO2(g)     

Shiba  Sadataka  Hirata  Yushi  Yagi  Shunsaku 《Water, air, and soil pollution》2001,130(1-4):307-312

Growing cloud droplets absorb such atmospheric gaseous pollutant as SO₂(g), condensing atmospheric water vapor into themselves. Then, the cloud droplets are acidified by absorption of SO₂(g) during condensational growth on cloud condensation nuclei (CCN). Characteristics of this process, which is a part of rainout, have not been made clear yet. In order to estimate the contribution of rainout to acid rain formation, the acidification of growing cloud droplets is investigated numerically, using a mathematical model. The numerical simulations show that: (1) the time to attain the equilibrium state for mass transfer (acidity and growth) and heat transfer (temperature) is much longer than the time for disappearance of CCN; (2) time variation of acidity and temperature of cloud droplets are greatly dependent on the existence of undissolved CCN; and (3) there seems to be a close correlation between the time variation of the acidity and that of the temperature.  相似文献   

Potential and promisingness of technical options for mitigating greenhouse gas emissions from rice cultivation in Southeast Asian countries     

Kazuyuki Yagi  Patikorn Sriphirom  Nittaya Cha-un  Kanlayanee Fusuwankaya  Amnat Chidthaisong  Beau Damen 《Soil Science and Plant Nutrition》2020,66(1):37-49

ABSTRACT

Paddy fields are considered as one of the most important sources of anthropogenic methane (CH₄) and nitrous oxide (N₂O) emissions. While several technical options have been proposed to reduce these emissions, gaps in data and information based on application of these options in the field are a key barrier to scaling-up. To address these gaps, we conducted a review of literature to analyze the potential of technical options in Southeast Asia (SEA). Using screening criteria based on reliability of experimental data, 31 region-specific cases were selected for the analysis. A meta-analysis indicated that water management options, including single and multiple drainage approaches such as alternative wetting and drying (AWD), significantly reduced CH₄ emissions by 35% as a mean effect size (95% confidential interval: 41–29%), as well as the combined effects of CH₄+N₂O (net GWP) by 29% (36–23%). The effect on reducing CH₄ emissions in the dry season was significantly larger than that in the wet season. Application of biochar reduced both CH₄ and N₂O emissions by 20% (40% to ?7%), while significantly increased rice yield by 28% (8–52%). Other options such as removal of rice straw from the previous crop, composting rice straw and manure, application of sulfate-containing fertilizer, and soil drying in the fallow season also have recognized potential to reduce emissions but require further data and consideration of possible trade-offs. Based on the analysis of mitigation potential, promising technical options were assessed by considering together with constraints and additional co-benefits in order to provide a useful guide for policy makers and rice value chain operators in SEA countries for adopting mitigation options in rice cultivation to tackle climate change and enhance agriculture sector sustainability.  相似文献   

有机肥无机肥配施对稻田氨挥发和水稻产量的影响   总被引：64，自引：17，他引：64  

李菊梅  徐明岗  秦道珠  李冬初  宝川靖和  八木一行 《植物营养与肥料学报》2005,11(1):51-56

在南方红壤区双季稻田进行田间试验,研究等氮、磷、钾量条件下,有机无机肥配施对稻田氨挥发及水稻产量的影响。结果表明,有机无机肥配合施用能显著地降低稻田氨挥发,减少氮素损失,提高氮肥利用率。单施化肥(尿素),其氨挥发损失达37.8%,而单施有机肥和有机无机肥各半配合施用,氨挥发损失分别为0.7％-1.0％和7.2％-18.2％。田间氨挥发持续的时间,早稻约在施肥后20d,晚稻为9-10d。虽然有机无机肥各半配合施用的水稻产量与单施化肥的相近,均比对照提高约70％,但前者的氮损失少,其氮肥利用率为34.9％,高于化肥处理(33.2％)和有机肥处理(28.0%)。有机无机肥配合施用对提高水稻产量和降低氮肥环境负效应的综合效应最佳。  相似文献   

N₂O and NO production in various Chinese agricultural soils by nitrification     

Weiguo Cheng  Kazuyuki Yagi 《Soil biology & biochemistry》2004,36(6):953-963

Eleven types of agricultural soils were collected from Chinese uplands and paddy fields to compare their N₂O and NO production by nitrification under identical laboratory conditions. Before starting the assays, all air-dried soils were preincubated for 4 weeks at 25 °C and 40% WFPS (water-filled pore space). The nitrification activities of soils were determined by adding (NH₄)₂SO₄ (200 mg N kg⁻¹ soil) and incubating for 3 weeks at 25 °C and 60% WFPS. The net nitrification rates obtained fitted one of two types of models, depending on the soil pH: a zero-order reaction model for acidic soils and one neutral soil (Group 0); or a first-order reaction model for one neutral soil and alkaline soils (Group 1). The results suggest that pH is the most important factor in determining the kinetics of soil nitrification from ammonium. In the Group 1 soils, initial emissions (i.e. during the first week) of N₂O and NO were 82.6 and 83.6%, respectively, of the total emissions during 3 weeks of incubation; in the Group 0 soils, initial emissions of N₂O and NO were 54.7 and 59.9%, respectively, of the total emissions. The net nitrification rate in the first week and second-third weeks were highly correlated with the initial and subsequent emissions (i.e. during the second and third weeks), respectively, of N₂O and NO. The average percentages of emitted (N₂O+NO)-N relative to net nitrification N in initial and subsequent periods were 2.76 and 0.59 for Group 0, and 1.47 and 0.44 for the Group 1, respectively. The initial and subsequent emission ratios of NO/N₂O from Group 0 (acidic) soils were 3.77 and 2.52 times, respectively, higher than those from Group 1 soils (P<0.05).  相似文献   

Rice root-derived carbon input and its effect on decomposition of old soil carbon pool under elevated CO₂     

Zhong Li  K. Yagi 《Soil biology & biochemistry》2004,36(12):1967-1973

Rice (Oryza sativa) was grown in sunlit, semi-closed growth chambers (4×3×2 m, L×W×H) at 650 μl l⁻¹ CO₂ (elevated CO₂) to determine: (1) rice root-derived carbon (C) input into the soil under elevated CO₂ in one growing season, and (2) the effect of the newly input C on decomposition of the more recalcitrant native soil organic C. The initial δ¹³C value of the experimental soil was −25.8‰, which was 6‰ less depleted in ¹³C than the plants grown under elevated CO₂. Significant changes in δ¹³C of the soil organic C were detected after one growing season. The amount of new soil C input was estimated to be 0.9 t ha⁻¹ (or 2.1%) at 30 kg N ha⁻¹ and 1.8 t ha⁻¹ (4.1%) at 90 kg N ha⁻¹. Changes in soil δ¹³C suggested that the surface 5 cm of soil received more C input from plants than soils below. Laboratory incubation (25 °C) of soils from different horizons indicated that increased availability of the labile plant-derived C in the soil reduced decomposition of the native soil organic C. Provided the retardant effect of the new C on old soil organic C holds in the field in the longer-term, paddy soils will likely sequester more C from the atmosphere if more plant C enters the soil under elevated atmospheric CO₂.  相似文献   

Soil microbial biomass and activities in a Japanese Andisol as affected by controlled release and application depth of urea   总被引：1，自引：0，他引：1  

H. Y. Chu  Y. Hosen  K. Yagi  K. Okada  O. Ito 《Biology and Fertility of Soils》2005,42(2):89-96

This experiment was conducted in maize field plots to study the effects of controlled release and application depth of urea on soil microbial biomass and activities at two depths of surface soil of a Japanese Andisol from June to September, 2001. Three N amendment treatments and a Control were included in this experiment: deep application (8 cm) of controlled release urea; deep application (8 cm) of conventional urea; surface application of conventional urea; Control, without N application. Prior to this experiment, the field plots received the same N fertilizer treatments for two consecutive years under maize/barley rotation. Soil microbial biomass, dehydrogenase and nitrification activities exhibited great vertical and temporal variations during the maize growth season, and the microbial biomass was significantly correlated to soil water-filled pore space (p<0.01). N fertilization did not significantly affect the microbial biomass, but greatly increased the dehydrogenase and nitrification activities. The increase in the microbial activities following N fertilization was not attributed to the increase in microbial biomass but to the increase in intrinsic microbial activities. Controlled release urea was found to continuously affect the dehydrogenase activity over a shorter distance, while conventional urea could greatly increase the enzyme activity for a shorter period of time. Both controlled release and deep application of urea had potentials to reduce the nitrification activity and suggested that the nitrate production might be decreased in 0–10 cm surface soil. Deep application of urea increased aboveground N uptake by maize and then the recovery rate of N fertilizer, whereas controlled release of urea greatly increased grain yield and N uptake by grain.  相似文献