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Using coloured roots to study root interaction and competition in intercropped legumes and non-legumes

Journal of Plant Ecology 2010年第3期3卷 191-199页

作者： Giacomo Tosti kristian thorup-kristensen Department of Agriculture and Environmental Sciences University of PerugiaBorgo XX Giugno 7406121 PerugiaItaly Department of Agriculture and Ecology Faculty of Life SciencesUniversity of CopenhagenHøjbakkegaards Alle 13DK-2630 TaastrupDenmark

Aims Root interactions between neighbour plants represent a fundamental aspect of the competitive dynamics in pure stand and mixed cropping *** comprehension of such phenomena places big methodological challenges,and still needs *** objectives of this work were(i)to test if a species with coloured roots can be used to examine the interaction in a legume-non-legume intercropping system;(ii)to verify the importance of initial root growth on the successive root development ofmixture component plants;(iii)to test if the root interaction in the shallowlayers has consequences for deep root growth and(iv)to compare the effect of intraspecific and interspecific competition on root development and biomass *** A detailed study on root growth and interaction was carried out using rhizotron tubes where two legume species were grown in pure stands or were intercropped with red beet,a variety of Beta vulgaris *** clear red *** the rhizotrons,the three species were grown either without competitors,with two plants of the same species to measure intraspecific competition or with one legume and one red beet plant to study interspecific *** use of mixtures where one component has clearly coloured roots,together with several scalar measurements of root depth and proliferation,allowed the measurement of the root system of each species when grown in the *** findings The use of rhizotron tubes coupled with species with coloured roots represented a valuable method to study the belowground interaction in mixed cropping *** initial root growth was a very important feature for the subsequent dominance of a species and it was not related to seed *** root growth was also important because the root interactions in the shallower soil layers were found to influence the root growth in deeper *** root system of the red beet showed much faster and deeper growth than that of the legumes,and made red beet

关键词： red beet root competition root interaction root proliferation rhizotron

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Size-asymmetric root competition in deep,nutrient-poor soil

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Journal of Plant Ecology 2019年第1期12卷 78-88页

作者： Camilla Ruø Rasmussen Anne Nygaard Weisbach kristian thorup-kristensen Jacob Weiner Department of Plant and Environmental Sciences University of CopenhagenHøjbakkegaard Allé13Taastrup DK-2630Denmark Department of Plant and Environmental Sciences University of CopenhagenThorvaldsensvej 40Frederiksberg DK-1871Denmark

Aims There is much evidence that plant competition below ground is size symmetric,*** competing plants share contested resources in proportion to their *** researchers have hypothesized that a patchy distribution of soil nutrients could result in size-asymmetric root *** tested this *** In a greenhouse experiment,Triticum aestivum(wheat)individ-uals of different initial sizes were grown alone or with below-ground competition from one neighbour,in 1 m tall,narrow containers in a nitrogen-poor field soil with(i)no added nitro-gen,(ii)nitrogen fertilizer mixed into the upper 50 cm,and(iii)the same amount of fertilizer mixed into a 20-30 cm deep *** measured total leaf length throughout the experiment,and above-ground biomass and nitrogen concentration at *** also measured root depth and frequency over time in a subset of *** Findings Competing plants were half the size of non-competing plants,meaning that root competition was very *** competition was size-asym-metric to some degree in all soil *** larger than the target plant showed a greater per-unit-size effect on target growth than neighbours smaller than the *** variation increased over time for competing individuals,but decreased for non-competing *** to expectations,the presence of a high-nutrient patch reduced the strength and size asymmetry of competition *** asym-metry in poor,deep soils may result from directionality in resource interception as roots compete for limited nutrients by growing deeper into soil layers that have not yet been *** competition can be size asymmetric,but not to the same degree as competition for light.

关键词： below-ground competition resource pre-emption size inequality size advantage Triticum aestivum

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Intercropping effect on root growth and nitrogen uptake at different nitrogen levels

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Journal of Plant Ecology 2015年第4期8卷 380-389页

作者： Javier Ramirez-Garcia Helle J.Martens Miguel Quemada kristian thorup-kristensen Dpto.Producción Vegetal:Fitotecnia ETSI AgrónomosAvd.Complutense s/nUniversidad Politécnica de Madrid28040 MadridSpain Department of Plant and Environmental Sciences University of CopenhagenHøjbakkegaards Alle 13DK-2630TaastrupDenmark

Aims Intercropping legumes and non-legumes may affect the root growth of both components in the mixture,and the non-legume is known to be strongly favored by increasing nitrogen(N)*** knowledge of how root systems affect the growth of the individual species is useful for understanding the interactions in intercrops as well as for planning cover cropping *** aim of this work was(i)to determine if different levels of N in the topsoil influence root depth(rD)and intensity of barley and vetch as sole crops or as an inter-cropped mixture and(ii)to test if the choice of a mixture or the N availability in the topsoil will influence the N uptake by deep *** In this study,we combined rhizotron studies with root extraction and species identification by microscopy with studies of growth,N uptake and 15N uptake from deeper soil layers,for studying the root interactions of root growth and N foraging for barley(Hordeum vul-gare l.)and vetch(Vicia sativa l.),frequently grown in mixtures as cover crops.N was added at 0(N0),50(N1)and 150(N2)kg N ha−*** roots discrimination relying on the anatomical and morphologi-cal differences observed between dicots and monocots proved to be a reliable method providing valuable data for the *** Findingsthe intercrop and the barley attained slightly higher root intensity(rI)and rD than the vetch,with values around 150 crosses m−1 and 1.4 m,respectively,compared to 50 crosses m−1 and 0.9 m for the *** deep soil layers,intercropping showed slightly larger rI values compared to the sole-cropped *** barley and the intercropping had larger root length density(r D)values(200-600 m m−3)than the vetch(25-130)at 0.8-1.2 m *** topsoil N supply did not show a clear effect on the rI,rD or r D;however,increasing topsoil N favored the proliferation of vetch roots in the intercropping at deep soil layers,with the barley:vetch root ratio ranging from 25 at N0 to 5 at *** N uptake of the barley was

关键词： grasses legumes cover crops crop mixture root discrimination labeled N

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Long-term rice-rice-green manure rotation changing the microbial communities in typical red paddy soil in South China

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Journal of Integrative Agriculture 2015年第12期14卷 2512-2520页

作者： GAO Song-juan ZHANG Ren-gang CAO Wei-dong FAN Yuan-yuan GAO Ju-sheng HUANG Jing BAI Jin-shun ZENG Nao-hua CHANG Dan-na Shimizu Katsu-yoshi kristian thorup-kristensen Key Laboratory of Plant Nutrition and Fertilizer Ministry of AgricultureInstitute of Agricultural Resources and Regional PlanningChinese Academy of Agricultural Sciences The Graduate School Chinese Academy of Agricultural Sciences College of Life Science and Technology Beijing University of Chemical Technology Soil and Fertilizer Institute Qinghai Academy of Agriculture and Forestry Sciences Qinghai University College of Resources and Environmental Sciences China Agricultural University Red Soil Experimental Station in Hengyang Chinese Academy of Agricultural Sciences Faculty of Agriculture Kagoshima University Department of Plant and Environmental Sciences University of Copenhagen

On the basis of a long-term（30 years） field experiment that involved four rotation systems, rice-rice-winter fallow（RRF）, rice-rice-ryegrass（RRG）, rice-rice-rape（RRP）, and rice-rice-milk vetch（RRV）, this study described the effects of green manure on the microbial communities in the red paddy soils using 454 pyrosequencing for the 16 S r RNA gene. The Chao1 richness and non-parametric Shannon＇s index increased in all soil samples that received green manure treatments. The communities＇ structures with the green manure applications were significantly dissimilar from that under the winter fallow. Using Metastats tests, many genera in the RRG, RRP and RRV soils were significantly different from those in the RRF soil, including a number of genera that functioned in the nitrogen and sulfur cycles. Analyses of the genera with these functions revealed the shifts in microbial ecosystem functions after long-term green manuring. Changes in the microbial communities increased the ammonium supply and decreased the soil acidification in green-manure-amended soils. Together, these data suggested powerful effects of green manure on both the microbial communities and the biogeochemical cycle driven by the shifts in bacterial functional groups.

关键词： green manure community structure community function 16S rRNA gene double rice

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High rate of clinically relevant improvement following anatomical total shoulder arthroplasty for glenohumeral osteoarthritis

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World Journal of Orthopedics 2024年第2期15卷 156-162页

作者： Marc Randall kristensen Nyring Bo Sanderhoff Olsen Alexander Amundsen Jeppe Vejlgaard Rasmussen Section for Shoulder and Elbow Surgery Department of Orthopaedic SurgeryHerlev and Gentofte University HospitalHellerup 2900Denmark

BACKGROUND The minimal clinically important difference(MCID)is defined as the smallest meaningful change in a health domain that a patient would identify as ***,an improvement that exceeds the MCID can be used to define a successful treatment for the individual *** To quantify the rate of clinical improvement following anatomical total shoulder arthroplasty for glenohumeral *** Patients were treated with the Global Unite total shoulder platform arthroplasty between March 2017 and February 2019 at Herlev and Gentofte Hospital,*** patients were evaluated preoperatively and 3 months,6 months,12 months,and 24 months postoperatively using the Western Ontario Osteoarthritis of the Shoulder index(WOOS),Oxford Shoulder Score(OSS)and Constant-Murley Score(CMS).The rate of clinically relevant improvement was defined as the proportion of patients who had an improvement 24 months postoperatively that exceeded the *** on previous literature,MCID for WOOS,OSS,and CMS were defined as 12.3,4.3,and 12.8 *** Forty-nine patients with a Global Unite total shoulder platform arthroplasty were included for the final *** age at the time of surgery was 66 years(range 49.0-79.0,SD:8.3)and 65%were *** patient was revised within the two years *** mean improvement from the preoperative assessment to the two-year follow-up was 46.1 points[95%confidence interval(95%CI):39.7-53.3,P<0.005]for WOOS,18.2 points(95%CI:15.5-21.0,P<0.005)for OSS and 37.8 points(95%CI:31.5-44.0,P<0.005)for *** years postoperatively,41 patients(87%)had an improvement in WOOS that exceeded the MCID,45 patients(94%)had an improvement in OSS that exceeded the MCID,and 42 patients(88%)had an improvement in CMS that exceeded the *** Based on three shoulder-specific outcome measures we find that approximately 90%of patients has a clinically relevant *** is a clear message when informing patients about the

关键词： Minimal clinically important difference Patient reported outcome measures Glenohumeral osteoarthritis Anatomical total shoulder arthroplasty Clinically relevant improvement

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Rethinking neurodegenerative diseases:neurometabolic concept linking lipid oxidation to diseases in the central nervous system

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Neural Regeneration Research 2024年第7期19卷 1437-1445页

作者： Steinunn Sara Helgudóttir Anne Skøttrup Mørkholt Jacek Lichota Preben Bruun-Nyzell Mads Christian Andersen Nanna Marie Juhl kristensen Amanda Krøger Johansen Mikela Reinholdt Zinn Hulda Maria Jensdóttir John Dirk Vestergaard Nieland 2N Pharma ApS NOVI Science ParkAalborgDenmark Molecular Pharmacology Group Department of Health Science and TechnologyAalborg UniversityAalborgDenmark

Currently,there is a lack of effective medicines capable of halting or reve rsing the progression of neurodegenerative disorde rs,including amyotrophic lateral sclerosis,Parkinson s disease,multiple sclerosis,or Alzheimer s *** the unmet medical need,it is necessary to reevaluate the existing para digms of how to to rget these *** considering neurodegenerative diseases from a systemic neurometabolic perspective,it becomes possible to explain the shared pathological *** innovative approach presented in this paper draws upon exte nsive research conducted by the authors and researchers *** this review,we highlight the importance of metabolic mitochondrial dysfunction in the context of neurodegenerative *** provide an overview of the risk factors associated with developing neurodegenerative disorders,including genetic,epigenetic,and environmental fa ***,we examine pathological mechanisms implicated in these diseases such as oxidative stress,accumulation of misfolded proteins,inflammation,demyelination,death of neurons,insulin resistance,dysbiosis,and neurotransmitter ***,we outline a proposal for the restoration of mitochondrial metabolism,a crucial aspect that may hold the key to facilitating curative therapeutic interventions for neurodegenerative disorders in forthcoming advancements.

关键词： brain disease carnitine palmitoyl transferase 1 epigenetics metabolism gut microbiome mitochondrial dysfunction neurodegeneration oxidative stress

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利用根管法对油菜和冬小麦苗期根系形态的研究

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草业学报 2017年第4期26卷 134-142页

作者：高嵩涓曹卫东 thorup-kristensen kristian 中国农业科学院农业资源与农业区划研究所农业部植物营养与肥料重点实验室北京100081 中国农业科学院研究生院北京100081 青海大学青海省农林科学院土壤肥料研究所青海西宁810016 哥本哈根大学植物与环境科学学院丹麦哥本哈根2630

快速、准确的根系原位观测方法是根系研究中的重要技术,本研究介绍了一种根管盆栽方法,该方法在透明PVC管内种植作物,通过遮光膜保持管内黑暗环境,以实现在作物生长过程中对其根系生长的原位动态观测,且根系生长环境更接近田间实际情况... 详细信息

快速、准确的根系原位观测方法是根系研究中的重要技术,本研究介绍了一种根管盆栽方法,该方法在透明PVC管内种植作物,通过遮光膜保持管内黑暗环境,以实现在作物生长过程中对其根系生长的原位动态观测,且根系生长环境更接近田间实际情况,并可通过改变根管长度、半径等将其应用于田间深根作物的研究中。利用此方法、结合根系扫描技术分析了油菜和冬小麦从发芽到出苗后16 d时的根系生长情况。结果表明,出苗后7和16 d冬小麦根系和地上部干物重均大于油菜,出苗后16 d冬小麦和油菜根冠比分别为0.513和0.372。大部分根系分布在0~16 cm表层土壤中,出苗后16 d冬小麦和油菜表层土壤中的根长在总根长中的比例分别为62.60%和67.76%,根系总表面积、总体积和一级侧根数均为表层土壤中占比最多,在出苗后7 d,总根长、总表面积、总体积和一级侧根数均为冬小麦显著高于油菜,而在出苗后16 d,两种作物的总根长和总表面积差别不大,说明油菜根系生长呈先缓后快趋势。表层土壤中根系平均直径小于底层土壤,油菜根系平均直径小于冬小麦,油菜和冬小麦的根系直径均大部分在0~0.50 mm之间,随着根系生长,较细的侧根逐渐增多,根系平均直径变小。出苗后16 d内的冬小麦根系伸长速率为1.83 cm/d,大于油菜的1.51 cm/d。因此,冬小麦苗期根系生长快于油菜,油菜根系呈先缓后快的生长特性。本研究介绍的根管法是一种原位研究根系的有效方法。

关键词：根系生长根系形态根管法

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Removal of chromophoric dissolved organic matter under combined photochemical and microbial degradation as a response to different irradiation intensities

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Journal of Environmental Sciences 2022年第8期34卷 76-86页

作者： Theis Kragh Kaj Sand-Jensen Emil kristensen Ole Pedersen Mikkel Madsen-Фterbye Department of Biology University of Southern DenmarkSyddanmark 5230Denmark Freshwater Biological Laboratory Department of BiologyUniversity of CopenhagenCopenhagen 2100Denmark

Throughout the freshwater continuum, Dissolved Organic Carbon(DOC) and the colored fraction, Chromophoric Dissolved Organic Material(CDOM), are continuously being added,removed, and transformed, resulting in changes in the chromophoricity and lability of organic matter over time. We examined, experimentally, the effect of increasing irradiationintensities on the combined photochemical and microbial degradation of CDOM and *** was done by using a simulated mixed water column: aged water from a humic lake was exposed to four irradiation-intensities – representing winter, early and late spring, and summer conditions(0.10, 0.16, 0.36, and 0.58 W/m^(2)) – and compared with dark controls over 37days. We found a linear relationship between CDOM degradation and irradiation-intensities up to 0.36 W/m^(2);the degradation rate saturated at higher intensities, both at specific wavelengths and for broader intervals. After 37 days at high irradiation-intensity, CDOM absorption of irradiation at 340 nm had been reduced by 41%;48% of DOC had been removed and DOC degradation continued to increase. Aromaticity(SUVA254) declined significantly over 37 days at the two lowest but not at the two highest UV-intensities;levels in unexposed control water remained constant. Direct observations of the humic lake showed that CDOM absorption of irradiation(340 nm) declined by 27% from winter to summer. A model based on hydrological CDOM input and CDOM degradation calculated from field measurements of UV-radiation and experimental CDOM degradation with UV-exposure from sunlight accurately predicted the annual course as observed in the lake. With no external CDOM input,92% of the CDOM could be degraded in a year. The results support the notion that combined photochemical and microbial CDOM degradation can be remarkably higher in lakes than previously thought and that humic lakes retain their color due to light absorption by ongoing CDOM input.

关键词： Biodegradation Brownification Carbon cycling CDOM DOC Humic lake Photobleaching UV-bleaching

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Fatty acid hydratase for value-added biotransformation:A review

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Chinese Journal of Chemical Engineering 2020年第8期28卷 2051-2063页

作者： Yan Zhang Bekir Engin Eser Peter kristensen Zheng Guo Department of Engineering Faculty of Science and TechnologyAarhus UniversityGustav wieds vej 108000 AarhusDenmark Faculty of Engineering and Science Department of Chemistry and BioscienceAalborg University9220 AalborgDenmark

The synthesis of hydroxy fatty acids(HFAs) from renewable oil feedstock by addition of water onto C_C bonds has attracted great attention in recent years. Given that selective asymmetric hydration of non-activated C_C bonds has been proven difficult to achieve with chemical catalysts, enzymatic catalysis by fatty acid hydratases(FAHs) presents an attractive alternative approach to produce value-added HFAs with high regio-, enantioand stereospecificity, as well as excellent atom economy. Even though FAHs have just been investigated as a potential biocatalyst for a decade, remarkable information about FAHs in different aspects is available;however, a comprehensive review has not been archived. Herein, we summarize the research progresses on biochemical characterization, structural and mechanistic determination, enzyme engineering, as well as biotechnological application of FAHs. The current challenges and opportunities for an efficient utilization of FAHs in organic synthesis and industrial applications are critically discussed.

关键词： Hydroxy fatty acids Fatty acid hydratases Enzyme characterization Catalytic mechanism Enzyme engineering Biotransformation

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High frame rate multi-resonance imaging refractometry with distributed feedback dye laser sensor

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Light(Science & Applications) 2015年第1期4卷 410-414页

作者： Christoph Vannahme Martin Dufva Anders kristensen Technical University of Denmark Department of Micro-and NanotechnologyDTU NanotechDK-2800 Kgs.LyngbyDenmark

High frame rate and highly sensitive imaging of refractive index changes on a surface is very promising for studying the dynamics of dissolution,mixing and biological processes without the need for ***,a highly sensitive distributed feedback(DFB)dye laser sensor for high frame rate imaging refractometry without moving parts is *** dye lasers are low-cost and highly sensitive refractive index *** unique multi-wavelength DFB laser structure presented here comprises several areas with different grating *** two dimensions of space is enabled by analyzinglaser light from all areasin parallelwith an imaging *** this multi-resonance imaging refractometry method,the spatial position in one direction is identified from the horizontal,i.e.,spectral position of the multiple laser lines which is obtained from the spectrometer charged coupled device(CCD)*** orthogonal spatial position is obtained from the vertical spatial position on the spectrometer CCD array as in established spatially resolved ***,the imaging technique is demonstrated by monitoring the motion of small sucrose molecules upon dissolution of solid sucrose in *** omission of moving parts improves the robustness of the imaging system and allows a very high frame rate of up to 12 Hz.

关键词： distributed feedback laser label-free imaging laser sensor refractive index sensor

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