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Secondary Production of Macrobenthos in Mangrove Area of Tong'an Bay,China 被引量:2
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作者 ZHOU Xiping CAI Lizhe 《Journal of Ocean University of China》 SCIE CAS 2010年第2期151-156,共6页
Studies on secondary production lead to a better understanding of the functions of the macrobenthic ecosystem.Basedon the macrobenthic data obtained at 6 sampling stations from April 2006 to January 2007,Brey's(19... Studies on secondary production lead to a better understanding of the functions of the macrobenthic ecosystem.Basedon the macrobenthic data obtained at 6 sampling stations from April 2006 to January 2007,Brey's(1990)empirical formula wasapplied to calculate the secondary production of macrobenthos in the mangrove area of Tong'an Bay.The results showed that themean annual secondary production of macrobenthos was 13.24 gAFDWm-2-a-1.The mean secondary production in the mangrovehabitat was 12.22 gAFDWm-2-a-1,lower than that in the non-mangrove habitat,which was 15.29 gAFDWm-2-a-1.Two possible rea-sons existed for this difference.First,mollusk and crustacean,which contribute more to the secondary production,probably benefitfrom longer inundation period in the non-mangrove habitat.Second,the higher organic matter in the mangrove habitat results in hy-poxia in the bottom sediment,which may decrease the secondary production.The annual mean production-to-biomass(P/B)ratio inTong'an Bay was 1.17,with a ratio of 1.27 in the mangrove habitat and 0.96 in the non-mangrove habitat,which was coincident withthe much higher density of Limnodriloides sp.and Corophium sp.in the mangrove habitat than in the non-mangrove habitat.Themaximum secondary production and P/B ratio of macrobenthos both appeared at sampling station FL2 in April,2006(namelyApril-FL2)with values of 31.38 gAFDWm-2-a-1and 2.20,respectively.The macrobenthic secondary production in Tong'an Bay islower than those in other intertidal studies except that in Haitan Strait,the reason being the different sediment properties.The P/Bratio in Tong'an Bay was the lowest due to the high proportion of crustaceans in the macrobenthic community. 展开更多
关键词 secondary production MACROBENTHOS P/B ratio Tong'an Bay mangrove area
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Life history, secondary production and trophic basis of two dominant mayflies in a subtropical stream of China
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作者 闫云君 李晓宇 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2007年第1期106-115,共10页
Mayflies constitute a major part of macroinvertebrate biomass and production in Iotic ecosystems, and play an important role in material cycle and energy flow. There are more than 250 species of mayflies in rivers and... Mayflies constitute a major part of macroinvertebrate biomass and production in Iotic ecosystems, and play an important role in material cycle and energy flow. There are more than 250 species of mayflies in rivers and streams of China. In order to learn their ecological functions, an investigation on life cycle, production and trophic basis of dominant species of mayflies in a second-order branch of Hanjiang River basin, Hubei, China was carried out during June 2003 to June 2004. The results showed that the dominant mayfly species Epeorus sp. and Caenis sp. developed two generations per year; in term of Epeorus sp., pupation mainly occurred in spring and then from late summer to early autumn, while Caenis sp. pupated in spring and autumn. The abundance and biomass of the Epeorus sp. population peaked twice (1 226 ind/m^2, 3.142 5g/m^2) in April and June. Caenis sp. also had two peaks (307ind/m^2, 1.590 g/m^2), but in February and June. Cohort production and cohort P/B ratio of Epeorus sp. were 161.009 g/m2 wet weight and 7.7, respectively, and annual production and P/B ratio were 267.46g/m^2.a wet weight and 15.4, respectively; cohort production and P/B ratio of Caenis sp. were 26.7995g/m^2 wet weight and 4.7, its annual production and P/B ratio were 53.60 g/m2.a wet weight and 9.4, respectively. For Epeorus sp., the proportions contributing to secondary production of the main food types were: amorphous detritus, 33.46%; fungi, 10.83%; vascular plant detritus, 1.80%; diatoms, 53.90%; for Caenis sp., the proportions were 70.79%, 6.90%, 3.52% and 18.77%, respectively. 展开更多
关键词 Macrozoobenthos MAYFLY secondary production Epeorus sp Caenis sp Heizhuchong Stream
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Estimates of Autumntime Benthic Secondary Production in Laizhou Bay and Adjacent Bohai Sea Waters
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作者 HUA Er ZHOU Hong ZHANG Zhinan YU Zishan 《Journal of Ocean University of China》 SCIE CAS 2010年第3期279-285,共7页
The whole metazoan community inhabiting Laizhou Bay and adjacent Bohai Sea waters were sampled in late autumn, 2006. Secondary production estimates for macrofauna and meiofauna were made separately. Total benthic seco... The whole metazoan community inhabiting Laizhou Bay and adjacent Bohai Sea waters were sampled in late autumn, 2006. Secondary production estimates for macrofauna and meiofauna were made separately. Total benthic secondary production was as high as 8.38 ±4.08 g ash-free dry weight (AFDW) m^-2 a^-1, which represented the autumn production level. In general, macrofaunal secondary production in Laizhou Bay was much lower than that in adjacent Bohai Sea areas. In contrast, meiofaunal secondary production in Laizhou Bay was higher than that in adjacent Bohai Sea areas. Macrofatma contributed 61% to benthic secondary production (5.09 ±3.26 g AFDW m^-2 a^-1), lower than the value in previous studies in Bohai Sea. Sediment granulometric characteristics and bottom-water salinity could explain the substantial variability in the macrofauna biomass and production. Meiofaunal production was an important component of benthic production and exceeded macrofauna production under exceptional conditions, e.g. in Laizhou Bay, where macrofauna was restricted. Chlorophyll pigments (Chl-a) concentrations in sediment explained the general meiofaunal biomass and production distribution here. 展开更多
关键词 benthic secondary production MEIOFAUNA MACROFAUNA Laizhou Bay the Bohai Sea
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Estimation of Some Plant Secondary Products in Urtica dioica L., Viola odorata L. and Melissa officinalis L. Naturally Grown in Hawraman-Kurdistan Region of Iraq
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作者 Abdulsalam Abdulrahman Rasool Kadhm Abdullah Muhammad 《Journal of Agricultural Science and Technology(B)》 2013年第7期480-486,共7页
The plant aerial parts of three species, Urtica dioica L., Viola odorata L. and Melissa officinalis L. were collected at randomly-different locations, according to altitudes in May 2010. The aerial parts of Urtica wer... The plant aerial parts of three species, Urtica dioica L., Viola odorata L. and Melissa officinalis L. were collected at randomly-different locations, according to altitudes in May 2010. The aerial parts of Urtica were collected within three replications from different locations: Biare 1,090 masl (meters above sea level), Tawile 1,450 masl and Awiser 1,680 masl. The aerial parts of Viola and Melissa were collected randomly within three replications at different locations: Biare 1,090 masl, Degashikhan 1,250 masl and Tawile 1,450 masl. The extracts of the aerial parts of these species were purified by filtrations for several times in preparation for HPLC analyses. The chromatograms of Urtica indicated the presence of five major important alkaloid components (fragrine, benzylisoquinoline, scopoletin, glucoquinone and dotriacotaine) and ten major important phenolic compounds (formic acid, tannin, chlorogenic acid, caffeoylmalic acid, anthocyanine, quercetin, zeaxanthin, luetin epoxide, coumarine and vanillin). All the concentrations of alkaloid and phenolic compounds were increased significantly due to higher altitudes, except that of alkaloid dotriacotaine. The chromatograms of Viola indicated the presence of four major important alkaloid components (violine, isoquinoline, cycloviolacin and luteolin-3-glucoronide) and ten major important phenolic compounds (formic acid, tannin, chlorogenic acid, caffeoylmalic acid, anthocyanine, quercetin, zeaxanthin, luetin epoxide, coumarine and vanillin). The results of the influence of altitudes showed that the concentrations of all alkaloids and phenolic compounds were increased significantly due to higher altitudes, except that of the alkaloid luteolin-3-glucoronide and the phenolic compounds zeaxanthin and luetin epoxide. The chromatograms of Melissa indicated the presence of five major essential oils (pinene, linalool, citronellol, geraniol and rosmarinic acid). Their quantitative evaluations were influenced by altitudes indicating that the concentrations of all oils were increased significantly due to the higher altitude, except that of the pinene. 展开更多
关键词 Urtica dioica L. Viola odorata L. Melissa officinalis L. ALTITUDES secondary products medicinal plants
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Atyid Shrimps Production and Biomass Turnover in Masanga Mabe Equatorial Rain-Forest Stream of Congo Basin (Kisangani, DR Congo)
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作者 Alidor Busanga Kankonda Ali-Patho Ulyel Nathan Utshiudienyema Nyongombe 《Journal of Environmental Science and Engineering(B)》 2015年第2期103-109,共7页
Decapod crustaceans are one of the dominant faunal components of most tropical streams. However, several aspects concerning their biology and ecology are poorly known, especially in intertropical Africa. The aim of th... Decapod crustaceans are one of the dominant faunal components of most tropical streams. However, several aspects concerning their biology and ecology are poorly known, especially in intertropical Africa. The aim of this study was to investigate the production of the atyid shrimps in Masanga Mabe, an equatorial lowland forest stream of Kisangani region. Samplings were undertaken biweekly from September 2000 to August 2003 with Surber net in four study sites. A total of 14,878 atyid shrimps specimens were sampled, measured for carapace length, weighted and identified. Atyid production was estimated by size frequency method according to sites (1, 2 and 3). Atyid composition showed the existence of two species: C africana (Caridina africana) Kingsley 1882 and C togoensis (Caridina togoensis) Hilgendorf 1893. Specific production ranged from 1.35 g·DM·m^-2-year^-1 (grams dry mass per square meter per year) to 8.4 g·DM·m^-2-year^-1 for C. africana and 0.95 g·DM·m^-2-year^-1 to 4.55 g·DM·m^-2-year^-1 for C togoensis. Mean annual P/B ratios varied from 3.89 year1 to 4.37 year1 for C africana and from 3.83 year^-1 to 3.98 year^-1 for C togoensis. 展开更多
关键词 Atyid shrimps equatorial stream secondary production Kisangani.
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Amphipods fail to suppress the accumulation of Ulva lactuca biomass in eutrophic Yundang Lagoon 被引量:1
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作者 ZHENG Xinqing HUANG Lingfeng +1 位作者 WANG Qian LIN Rongcheng 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2014年第12期155-162,共8页
The Gross growth efficiency (GGE) is defined as the amount of consumer carbon produced relative to the amount of prey ingested in a given time interval. In population ecology, it can be considered as an index for th... The Gross growth efficiency (GGE) is defined as the amount of consumer carbon produced relative to the amount of prey ingested in a given time interval. In population ecology, it can be considered as an index for the ability of a consumer to convert the biomass of food into its population production. In this study, it was firstly applied to estimate the role of amphipods grazing in the biomass dynamics of macroalgae (Ulva lactuca) in Yundang Lagoon (a subtropical eutrophic coastal lagoon, Xiamen City, China). It was found that amphipods were the dominant group (82.2%-98.7%) in the benthic assemblage, in which five amphipod species (Corophium uenoi, Ampithoe valida, Grandidierella japonica, Grammaropsis laevipalmata andCa-prella panantis) were observed in the lagoon. However, onlyA. valida significantly consumedU. lactuca among these amphipod species. A series of experiments were conducted to estimate the consumption of U. lactuca byA. valida. It was suggested that the monthly secondary production (P) ofA. valida using size frequency method ranged from 2.39 to 13.68 g/m2.GGEofA. valida exponentially reduced with body size and was closely associated with water temperature. Therefore,GGE equation for different months using the temperature recorded during the field investigation was fitted. The monthly consumption ofU. lactuca was figured out to be 86.7-1 549.0 g/m2 by the sum of consumption (P/GGE) byA. valida at different size, ac-counting for 2.0%-37.5% ofU. lactucaproduction. It indicates that the grazing effect ofA. valida did play a role in reducingthe accumulation ofU. lactucabiomass whenA. valida was abundant, but it finally fails to limit the U. lactucagrowth in Yundang Lagoon. Low abundance of A. valida and high nutrient loading may be two major reasons for the outbreak ofU. lactuca bloom in the lagoon. 展开更多
关键词 AMPHIPODS Ampithoe valida consumption gross growth efficiency secondary production Ulva lactuca
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PCDD/Fs emission, risk characterization, and reduction in China's secondary copper production industry
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作者 Haiqian LI Yonglong LU Li LI 《Frontiers of Environmental Science & Engineering》 SCIE EI CAS CSCD 2013年第4期589-597,共9页
Secondary copper production is one of the key polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) emission sources in China, but research and data on this issue are rare. In 2004, when the Stockholm Conven... Secondary copper production is one of the key polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) emission sources in China, but research and data on this issue are rare. In 2004, when the Stockholm Convention entered into force in China, PCDD/Fs emissions from secondary copper production contributed to 32.2% of the total release. In this paper, PCDD/Fs emission dynamics from secondary copper industry were discussed and cumulative risks were characterized. From 2004 to 2009, industrial policies played an indirect role in PCDD/Fs reduction, but its effects are still limited. The Yangtze River Delta, Pearl River Delta and central regions were among the top three of dioxin emissions from secondary copper production in China. Shanghai, Shan- dong, Zhejiang, and Jiangxi had comparatively higher accumulated risk and were recommended as the priority regions for promoting PCDD/Fs emission control in China. From 2009 to 2015, the PCDD/Fs emission dynamics in the secondary copper industry were presented through simulation. PCDD/Fs emission equations were established, resulting in the recommendation of control technology conversion rate at 30% for small scale smelters and 51%- 57% for large and medium-sized enterprises in 2015. In conclusion, both indirect policy and direct control technology retrofitting should be integrated for more effective PCDD/Fs emission reduction in secondary copper industry. 展开更多
关键词 polychlorinated dibenzo-p-dioxins and diben-zofurans (PCDD/Fs) secondary copper production emis-sion risk China
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The Antioxidant Activity of Barley Malt Rootlet Extracts in Heated Corn Oil at Frying Temperature
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作者 Sravanthi Budaraju P. Kumar Mallikarjunan A. Saari Csallany 《Food and Nutrition Sciences》 2021年第9期899-914,共16页
In this study the antioxidant activity of barley malt rootlet (BMR) extracts w</span><span style="font-family:"">as</span><span style="font-family:""> evaluated in... In this study the antioxidant activity of barley malt rootlet (BMR) extracts w</span><span style="font-family:"">as</span><span style="font-family:""> evaluated in heat treated corn oil up to 5 hours at 185</span><span style="font-family:"">&deg;</span><span style="font-family:"">C frying temperature. The antioxidant activity </span><span style="font-family:"">of </span><span style="font-family:"">BMR extracts was measured at 25, 50, 100 and 150 ppm concentrations. The free and bound antioxidant phenolics were extracted from BMR using three different extraction methods. Conventional solvent extraction (CSE), microwave assisted extraction (MAE) and autoclave assisted pretreated solvent extraction (APSE). In the present experiment, the total phenolic content and antioxidant activity of the various extracts w</span><span style="font-family:"">ere</span><span style="font-family:""> measured. Thiobarbituric acid reactive substances (TBARS) assay was used to evaluate the ability of the BMR to protect lipid peroxidation in corn oil at 185</span><span style="font-family:"">&deg;</span><span style="font-family:"">C frying temperature. The formation of TBARS at 5 hours of heat treated corn oil ha</span><span style="font-family:"">s</span><span style="font-family:""> shown similar antioxidant levels in 150 ppm butylated hydroxytoluene (BHT) or MAE free phenolic extract added to corn oil. TBARS value for BHT was 1.896 ± 0.013 μg/mL of corn oil and for MAE was 1.896 ± 0.034 μg/mL of corn oil. The highest level of antioxidant activity was found for the free phenolic extracts. The order of inhibition of oxidation was found to be for free phenolics as follows: BHT (100 ppm) > APSE (50 ppm) > MAE (100 ppm) > CSE (100 ppm). 展开更多
关键词 Antioxidant Activity Autoclave Treatment Barley Malt Rootlets BHT Bound and Free Phenolics Corn Oil Lipid Peroxidation Microwave Assisted Extraction secondary Oxidation products Solvent Extraction
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Production of the Cancer-Preventive Glucoraphanin in Tobacco 被引量:3
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作者 Michael Dalgaard Mikkelsen Carl Erik Olsen Barbara Ann Halkier 《Molecular Plant》 SCIE CAS CSCD 2010年第4期751-759,共9页
Epidemiological studies have demonstrated reduced risk of developing cancer upon consumption of diets rich in cruciferous vegetables. This chemoprevention has been largely attributed to the presence of the natural pro... Epidemiological studies have demonstrated reduced risk of developing cancer upon consumption of diets rich in cruciferous vegetables. This chemoprevention has been largely attributed to the presence of the natural products glu- cosinolates, particularly the methionine-derived glucoraphanin from broccoli. Improved nutrition by functional foods or health-promoting dietary supplements is an attractive means for prevention of lifestyle-based diseases. Towards this goal, we have engineered the glucoraphanin pathway into tobacco. First, we engineered elongation of the side chain of methionine to produce the key intermediate dihomo-methionine. This process is catalyzed through two cycles in a chain-elongation pathway that takes place partly in the cytosol and partly in the chloroplast. Second, by coupling the five enzymes of the chain-elongation pathway to eight enzymes of the glucosinolate pathway, we show production of glucoraphanin together with other glucosinolates derived from chain-elongated isoleucine and/or leucine. The conver- sion of methionine to glucoraphanin is obtained via 14 intermediates. Demonstrating the production of the high-value glucoraphanin in a heterologous host has great potential in the food and medicinal industry as a means to generate a stable, rich source of glucoraphanin for the benefit of human health. 展开更多
关键词 COMPARTMENTATION secondary metabolism/natural products AGROBACTERIUM Arabidopsis TOBACCO GLUCOSINOLATES metabolic engineering.
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Rapid generation of recombinant Pseudomonas putida secondary metabolite producers using yTREX 被引量:2
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作者 Andreas Domrose Robin Weihmann +3 位作者 Stephan Thies Karl-Erich Jaeger Thomas Drepper Anita Loeschcke 《Synthetic and Systems Biotechnology》 SCIE 2017年第4期310-319,共10页
Microbial secondary metabolites represent a rich source of valuable compounds with a variety of applications in medicine or agriculture.Effective exploitation of this wealth of chemicals requires the functional expres... Microbial secondary metabolites represent a rich source of valuable compounds with a variety of applications in medicine or agriculture.Effective exploitation of this wealth of chemicals requires the functional expression of the respective biosynthetic genes in amenable heterologous hosts.We have previously established the TREX system which facilitates the transfer,integration and expression of biosynthetic gene clusters in various bacterial hosts.Here,we describe the yTREX system,a new tool adapted for one-step yeast recombinational cloning of gene clusters.We show that with yTREX,Pseudomonas putida secondary metabolite production strains can rapidly be constructed by random targeting of chromosomal promoters by Tn5 transposition.Feasibility of this approach was corroborated by prodigiosin production after yTREX cloning,transfer and expression of the respective biosynthesis genes from Serratia marcescens.Furthermore,the applicability of the system for effective pathway rerouting by gene cluster adaptation was demonstrated using the violacein biosynthesis gene cluster from Chromobacterium violaceum,producing pathway metabolites violacein,deoxyviolacein,prodeoxyviolacein,and deoxychromoviridans.Clones producing both prodigiosin and violaceins could be readily identified among clones obtained after random chromosomal integration by their strong color-phenotype.Finally,the addition of a promoter-less reporter gene enabled facile detection also of phenazine-producing clones after transfer of the respective phenazine-1-carboxylic acid biosynthesis genes from Pseudomonas aeruginosa.All compounds accumulated to substantial titers in the mg range.We thus corroborate here the suitability of P.putida for the biosynthesis of diverse natural products,and demonstrate that the yTREX system effectively enables the rapid generation of secondary metabolite producing bacteria by activation of heterologous gene clusters,applicable for natural compound discovery and combinatorial biosynthesis. 展开更多
关键词 Synthetic biology Yeast recombinational cloning Tn5 transposition Heterologous gene cluster expression secondary metabolite production Pseudomonas putida
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Bioreactor technology for clonal propagation of plants and metabolite production
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作者 Nazmul H. A. Mamun Ulrika Egertsdotter Cyrus K. Aidun 《Frontiers in Biology》 CAS CSCD 2015年第2期177-193,共17页
Plant cell culture in bioreactors is an enabling tool for large scale production of clonal elite plants in agriculture, horticulture, forestry, pharmaceutical sectors, and for biofuel production. Advantages of bioreac... Plant cell culture in bioreactors is an enabling tool for large scale production of clonal elite plants in agriculture, horticulture, forestry, pharmaceutical sectors, and for biofuel production. Advantages of bioreactors for plant cell culture have resulted in various types of bioreactors differing in design, operating technologies, instrumentations, and construction of culture vessels. In this review, different types of bioreactors for clonal propagation of plants and secondary metabolites production are discussed. Mechanical and biochemical parameters associated with bioreactor design, such as aeration, flow rate, mixing, dissolved oxygen, composition of built-up gas in the headspace, and pH of the medium, are pivotal for cell morphology, growth, and development of cells within tissues, embryos, and organs. The differences in such parameters for different bioreactor designs are described here, and correlated to the plant materials that have been successfully cultured in different types of bioreactors. 展开更多
关键词 bioreactor types mechanical and biochemical parameters plant cell culture plant clonal propagation secondary metabolite production
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Biodiversity variability of macrobenthic in the Yellow Sea and East China Sea between 2001 and 2011
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作者 Xin-Zheng Li Hong-Fa Wang +6 位作者 Jin-Bao Wang Dong Dong Lin Ma Qi Kou Ji-Xing Sui Zhi-Bin Gan Bao-Lin Zhang 《Zoological Systematics》 CSCD 北大核心 2014年第4期459-484,共26页
In this study, we compared the biodiversity and ecological status of macrobenthos between 2001 and 2011 in terms of species composition, dominant species, abundance, biomass, diversity, and secondary productivity of m... In this study, we compared the biodiversity and ecological status of macrobenthos between 2001 and 2011 in terms of species composition, dominant species, abundance, biomass, diversity, and secondary productivity of macrobenthos in the Yellow Sea and East China Sea. The results indicate that the species abundances, biomass, and diversity in spring 2011 were all lower than those in autumn 2000 and spring of 2001. Most of the dominant species have changed from 2001 to 2011, with the exception of the echinoderm Ophiura sarsii vadicola that was dominant in these years. Small-sized animal species have increased possibly due to gradual environment deterioration such as the pollution and the climate warmer. 展开更多
关键词 Yellow Sea East China Sea MACROBENTHOS ECOLOGY BIODIVERSITY secondary productivity
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Coronatine-lnsensitive 1 (COI1) Mediates Transcriptional Responses of Arabidopsis thaliana to External Potassium Supply 被引量:4
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作者 Patrick Armengaud Rainer Breitling Anna Amtmann 《Molecular Plant》 SCIE CAS CSCD 2010年第2期390-405,共16页
The ability to adjust growth and development to the availability of mineral nutrients in the soil is an essential life skill of plants but the underlying signaling pathways are poorly understood. In Arab/dops/s thal/a... The ability to adjust growth and development to the availability of mineral nutrients in the soil is an essential life skill of plants but the underlying signaling pathways are poorly understood. In Arab/dops/s thal/ana, shortage of po- tassium (K) induces a number of genes related to the phytohormone jasmonic acid (JA). Using comparative microarray analysis of wild-type and coi1-16 mutant plants, we classified transcriptional responses to K with respect to their depen- dence on COI1, a central component of oxylipin signaling. Expression profiles obtained in a short-term experiment clearly distinguished between COil-dependent and COil-independent K-responsive genes, and identified both known and novel targets of JA-COIl-signaling. During long-term K-deficiency, coi-16 mutants displayed de novo responses covering similar functions as COil-targets except for defense. A putative role of JA for enhancing the defense potential of K-deficient plants was further supported by the observation that plants grown on low K were less damaged by thrips than plants grown with sufficient K. 展开更多
关键词 Hormonal regulation NUTRITION secondary metabolism/natural products transcriptome analysis plantinsect interactions Arabidopsis.
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Systemic RNAi in western corn rootworm, Diabrotica virgifera virgifera, does not involve transitive pathways 被引量:1
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作者 Huarong Li Andrew J. Bowling +6 位作者 Premchand Gandra Murugesan Rangasamy Heather E. Pence Robert E. McEwan Chitvan Khajuria Blair D. Siegfried Kenneth E. Narva 《Insect Science》 SCIE CAS CSCD 2018年第1期45-56,共12页
Western corn rootworm (WCR, Diabrotica virgifera virgifera LeConte) is highly sensitive to orally delivered double-stranded RNA (dsRNA). RNAi in WCR is systemic and spreads throughout the insect body. This raises ... Western corn rootworm (WCR, Diabrotica virgifera virgifera LeConte) is highly sensitive to orally delivered double-stranded RNA (dsRNA). RNAi in WCR is systemic and spreads throughout the insect body. This raises the question whether transitive RNAi is a mechanism that functions in WCR to amplify the RNAi response via production of secondary siRNA. Secondary siRNA production is achieved through RNA-dependent RNA polymerase (RdRP) activity in other eukaryotic organisms, but RdRP has not been identified in WCR and any other insects. This study visualized the spread of the RNAi- mediated knockdown of Dr v-ATPase C mRNA throughout the WCR gut and other tissues using high-sensitivity branched DNA in situ hybridization. Furthermore, we did not detect either secondary siRNA production or transitive RNAi in WCR through siRNA sequence profile analysis. Nucleotide mismatched sequences introduced into either the sense or antisense strand of v-ATPase C dsRNAs were maintained in siRNAs derived from WCR fed with the mismatched dsRNAs in a strand specific manner. The distribution of all siRNAs was restricted to within the original target sequence regions, which may indicate the lack of new dsRNA synthesis leading to production of secondary siRNA. Thus, the systemic spread of RNAi in WCR may be derived from the original dsRNA molecules taken up from the gut lumen. These results indicate that the initial dsRNA dose is important for a lethal systemic RNAi response in WCR and have implications in developing effective dsRNA traits to control WCR and in resistance management to prolong the durability of RNAi trait technology. 展开更多
关键词 corn rootworm DIABROTICA secondary siRNA production systemic RNAi transitive RNAi
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Metabolomic, Transcriptional, Hormonal, and Signaling Cross-Talk in Superroot2
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作者 Marc Morant Claus Ekstrom +8 位作者 Peter Ulvskov Charlotte Kristensen Mats Rudemo Carl Erik Olsen Jorgen Hansen Kirsten Jorgensena Bodil Jorgensen Birger Lindberg Moilera Soren Bak 《Molecular Plant》 SCIE CAS CSCD 2010年第1期192-211,共20页
Auxin homeostasis is pivotal for normal plant growth and development. The superroot2 (sur2) mutant was initially isolated in a forward genetic screen for auxin overproducers, and SUR2 was suggested to control auxin ... Auxin homeostasis is pivotal for normal plant growth and development. The superroot2 (sur2) mutant was initially isolated in a forward genetic screen for auxin overproducers, and SUR2 was suggested to control auxin conju- gation and thereby regulate auxin homeostasis. However, the phenotype was not uniform and could not be described as a pure high auxin phenotype, indicating that knockout of CYP83B1 has multiple effects. Subsequently, SUR2 was identified as CYP83B1, a cytochrome P450 positioned at the metabolic branch point between auxin and indole glucosinolate metabolism. To investigate concomitant global alterations triggered by knockout of CYP83B1 and the countermeasures chosen by the mutant to cope with hormonal and metabolic imbalances, 10-day-old mutant seedlings were characterized with respect to their transcriptome and metabolome profiles. Here, we report a global analysis of the sur2 mutant by the use of a combined transcriptomic and metabolomic approach revealing pronounced effects on several metabolic grids including the intersection between secondary metabolism, cell wall turnover, hormone metabolism, and stress responses. Metabolic and transcriptional cross-talks in sur2 were found to be regulated by complex interactions between both positively and negatively acting transcription factors. The complex phenotype of sur2 may thus not only be assigned to elevated levels of auxin, but also to ethylene and abscisic acid responses as well as drought responses in the absence of a water deficiency. The delicate balance between these signals explains why minute changes in growth conditions may result in the non-uniform phenotype. The large phenotypic variation observed between and within the different surveys may be reconciled by the complex and intricate hormonal balances in sur2 seedlings decoded in this study. 展开更多
关键词 Abiotic/environmental stress hormonal regulation metabolomics secondary metabolism/natural products transcriptome analysis development.
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