scholarly journals Dissecting the effects of nitrate, sucrose and osmotic potential on Arabidopsis root and shoot system growth in laboratory assays

2012 ◽  
Vol 367 (1595) ◽  
pp. 1489-1500 ◽  
Author(s):  
Peter Roycewicz ◽  
Jocelyn E. Malamy
Keyword(s):  
Root System ◽  
Osmotic Potential ◽  
Wide Spectrum ◽  
System Size ◽  
Growth Media ◽  
Target Tissue ◽  
Shoot Ratio ◽  
Root Shoot Ratio ◽  
Shoot System ◽  
The Impact

Studying the specific effects of water and nutrients on plant development is difficult because changes in a single component can often trigger multiple response pathways. Such confounding issues are prevalent in commonly used laboratory assays. For example, increasing the nitrate concentration in growth media alters both nitrate availability and osmotic potential. In addition, it was recently shown that a change in the osmotic potential of media alters the plant's ability to take up other nutrients such as sucrose. It can also be difficult to identify the initial target tissue of a particular environmental cue because there are correlated changes in development of many organs. These growth changes may be coordinately regulated, or changes in development of one organ may trigger changes in development of another organ as a secondary effect. All these complexities make analyses of plant responses to environmental factors difficult to interpret. Here, we review the literature on the effects of nitrate, sucrose and water availability on root system growth and discuss the mechanisms underlying these effects. We then present experiments that examine the impact of nitrate, sucrose and water on root and shoot system growth in culture using an approach that holds all variables constant except the one under analysis. We found that while all three factors also alter root system size, changes in sucrose and osmotic potential also altered shoot system size. In contrast, we found that, when osmotic effects are controlled, nitrate specifically inhibits root system growth while having no effect on shoot system growth. This effectively decreases the root : shoot ratio. Alterations in root : shoot ratio have been widely observed in response to nitrogen starvation, where root growth is selectively increased, but the present results suggest that alterations in this ratio can be triggered across a wide spectrum of nitrate concentrations.

scholarly journals DROUGHT-TOLERANT MAIZE GENOTYPES INVEST IN ROOT SYSTEM AND MAINTAIN HIGH HARVEST INDEX DURING WATER STRESS

2017 ◽  
Vol 15 (3) ◽  
pp. 450
Author(s):  
RONIEL GERALDO AVILA ◽  
PAULO CESÁR MAGALHÃES ◽  
AMAURI ALVES DE ALVARENGA ◽  
ALYNE DE OLIVEIRA LAVINSKY ◽  
CLEIDE NASCIMENTO CAMPOS ◽  
...  
Keyword(s):  
Water Stress ◽  
Root System ◽  
Dry Weight ◽  
Carbon Partitioning ◽  
Gas Exchanges ◽  
Drought Tolerant ◽  
Shoot Ratio ◽  
Root Shoot Ratio ◽  
Maize Genotypes ◽  
Source Sink

ABSTRACT – Drought is considered the primary limitation to agriculture and, can reduce grain yield by up to 60%when occurs at pre-flowering in maize. In this context this research, aimed to understand the maize genotypes behaviorto drought management and carbon partitioning between grain production and structures to maintain hydration whensubmitted to drought. Maize genotypes tolerant (DKB390 and P30F35) and sensitive (BRS1010 and 2B710) to droughtwere grown in a greenhouse using two water conditions: irrigated and stressed. Water deficit was imposed atpre-flowering and maintained for twelve days. Leaf water potential, gaseous exchange and male and female floweringinterval were evaluated. At the end of the cycle, production components and root/shoot ratio dry weight were evaluated.Drought-tolerant genotypes used root system as a mechanism of tolerance to drought, which ensure greater efficiencyin absorption and loss of water and, consequently, greater stomatal conductance during the drought, compared to thesensitive-genotypes. In addition, drought-tolerant genotypes showed greater stability in the source-sink relationship,exhibiting higher photosynthetic rate and harvest index.Keywords: water stress, carbon partitioning; root/shoot ratio dry weight, gas exchanges, Zea mays.GENÓTIPOS DE MILHO TOLERANTES À SECA INVESTEM EM SISTEMA RADICULARE MANTEM ALTO ÍNDICE DE COLHEITA DURANTE O ESTRESSE HÍDRICORESUMO- A seca é considerada restrição primária à agricultura, e no milho, quando ocorre no pré-florescimento,pode reduzir o rendimento de grãos em até 60%. Neste contexto, objetivou-se entender como genótipos de milhocontrastantes para tolerância à seca, gerenciam o particionamento de carbono entre produção de grãos e estruturasde manutenção da hidratação durante a seca. Para isso, em casa de vegetação cultivaram-se genótipos de milhotolerantes (DKB390 e P30F35) e sensíveis (BRS1010 e 2B710) à seca, em duas condições hídricas: irrigadonormal e déficit hídrico. No pré-florecimento foi imposto o déficit hídrico, que foi mantido por doze dias.Posteriormente avaliou-se o potencial hídrico foliar, trocas gasosas e intervalo de florescimento masculino e feminino.No final do ciclo, avaliaram-se os componentes de produção e a razão raiz/parte aérea. Constatou-se que, genótipostolerantes utilizaram preferencialmente sistema radicular como um mecanismo de tolerância à seca, o que garantiu aesses genótipos, maior eficiência entre a absorção e perda de água e, consequentemente, maior condutância estomáticadurante a seca, em relação aos genótipos sensíveis. Além disso, os genótipos tolerantes apresentaram maior equilíbrioem suas relações fonte e dreno, exibindo maiores taxa fotossintética e índice de colheita.Palavras-chave: estresse hídrico, particionamento de carbono, razão raiz/parte aérea, trocas gasosas, Zea mays.                                                     

scholarly journals Root system size of alfalfa varieties under different plant densities

2012 ◽  
Vol 60 (1) ◽  
pp. 9-16 ◽  
Author(s):  
Esmail Al-Mosanif ◽  
Karel Vejražka ◽  
Miroslav Jůzl ◽  
Karel Drápal
Keyword(s):  
Root System ◽  
Soil Layer ◽  
Weather Conditions ◽  
System Size ◽  
Plant Spacing ◽  
New Variety ◽  
Root System Size ◽  
Alfalfa Sprouts ◽  
Alfalfa Varieties ◽  
The Impact

The field experiment was established from pre-grown alfalfa sprouts in 2008. In 2009 and 2010, the harvest was carried out. The yield and the root size system (RSS) were evaluated in the total of five cuts. Two localities of diverse soil and weather conditions were selected. Žabčice is a dry location with a highly permeable sandy soil layer, but at the same time, with a considerable fluctuation of the underground water level; Troubsko, on the other hand, represented a location with a higher content of clay in soil suitable for growing alfalfa. The trial was established in two types of plant spacing – 25 × 25 cm (16 plants per m2) and 50 × 50 cm (4 plants per m2). Two alfalfa varieties were used – Hodonínka (an old variety) and Oslava (a new variety). The following factors were evaluated by statistical means: location, variety, plant spacing, and cut number. The effect of location on the above ground phytomass and the RSS value proved highly statistically decisive. The higher average values of above ground phytomass as well as RSS were achieved on the Troubsko location where the above ground phytomass was 19.57 t.ha−1 and RSS was 2.71 nanofarad (nF). The impact of the variety was highly statistically significant only in respect to RSS. The effect of variety on the alfalfa above ground phytomass was not proven. The higher average RSS values were reached by the Hodonínka variety (2.59 nF). The effect of the plant spacing on both the above ground phytomass and the RSS values was highly statistically significant. The higher average above ground phytomass was achieved when the 25 × 25 cm plant spacing was employed (18.64 t.ha−1). As for the RSS value, the case was exactly opposite – the higher average value was reached when the plant spacing was 50 × 50 cm (2.99 nF). The impact of the cut number on both the above ground phytomass and the RSS was highly statistically significant. The highest average above ground phytomass and root system size were measured in the third cut. The above ground phytomass was 30.36 t.ha‑1 and RSS was 3.86 nF.

scholarly journals DROUGHT-TOLERANT MAIZE GENOTYPES INVEST IN ROOT SYSTEM AND MAINTAIN HIGH HARVEST INDEX DURING WATER STRESS

2016 ◽  
Vol 15 (3) ◽  
pp. 450 ◽  
Author(s):  
RONIEL GERALDO AVILA ◽  
PAULO CESÁR MAGALHÃES ◽  
AMAURI ALVES DE ALVARENGA ◽  
ALYNE DE OLIVEIRA LAVINSKY ◽  
CLEIDE NASCIMENTO CAMPOS ◽  
...  
Keyword(s):  
Water Stress ◽  
Root System ◽  
Dry Weight ◽  
Carbon Partitioning ◽  
Drought Tolerant ◽  
Shoot Ratio ◽  
Root Shoot Ratio ◽  
Maize Genotypes ◽  
Female Flowering ◽  
Source Sink

ABSTRACT – Drought is considered the primary limitation to agriculture and, can reduce grain yield by up to 60% when occurs at pre-flowering in maize. In this context this research, aimed to understand the maize genotypes behavior to drought management and carbon partitioning between grain production and structures to maintain hydration when submitted to drought. Maize genotypes tolerant (DKB390 and P30F35) and sensitive (BRS1010 and 2B710) to drought were grown in a greenhouse using two water conditions: irrigated and stressed. Water deficit was imposed at pre-flowering and maintained for twelve days. Leaf water potential, gaseous exchange and male and female flowering interval were evaluated. At the end of the cycle, production components and root/shoot ratio dry weight were evaluated. Drought-tolerant genotypes used root system as a mechanism of tolerance to drought, which ensure greater efficiency in absorption and loss of water and, consequently, greater stomatal conductance during the drought, compared to the sensitive-genotypes. In addition, drought-tolerant genotypes showed greater stability in the source-sink relationship, exhibiting higher photosynthetic rate and harvest index.Keywords: water stress, carbon partitioning; root/shoot ratio dry weight, gas exchanges, Zea mays.GENÓTIPOS DE MILHO TOLERANTES À SECA INVESTEM EM SISTEMA RADICULARE MANTEM ALTO ÍNDICE DE COLHEITA DURANTE O ESTRESSE HÍDRICORESUMO- A seca é considerada restrição primária à agricultura, e no milho, quando ocorre no pré-florescimento, pode reduzir o rendimento de grãos em até 60%. Neste contexto, objetivou-se entender como genótipos de milho contrastantes para tolerância à seca, gerenciam o particionamento de carbono entre produção de grãos e estruturas de manutenção da hidratação durante a seca. Para isso, em casa de vegetação cultivaram-se genótipos de milho tolerantes (DKB390 e P30F35) e sensíveis (BRS1010 e 2B710) à seca, em duas condições hídricas: irrigado normal e déficit hídrico. No pré-florecimento foi imposto o déficit hídrico, que foi mantido por doze dias. Posteriormente avaliou-se o potencial hídrico foliar, trocas gasosas e intervalo de florescimento masculino e feminino. No final do ciclo, avaliaram-se os componentes de produção e a razão raiz/parte aérea. Constatou-se que, genótipos tolerantes utilizaram preferencialmente sistema radicular como um mecanismo de tolerância à seca, o que garantiu a esses genótipos, maior eficiência entre a absorção e perda de água e, consequentemente, maior condutância estomática durante a seca, em relação aos genótipos sensíveis. Além disso, os genótipos tolerantes apresentaram maior equilíbrio em suas relações fonte e dreno, exibindo maiores taxa fotossintética e índice de colheita.Palavras-chave: estresse hídrico, particionamento de carbono, razão raiz/parte aérea, trocas gasosas, Zea mays.

Shade Avoidance Influences Stress Tolerance in Maize

Weed Science ◽  
2011 ◽  
Vol 59 (3) ◽  
pp. 326-334 ◽  
Author(s):  
Eric R. Page ◽  
Weidong Liu ◽  
Diego Cerrudo ◽  
Elizabeth A. Lee ◽  
Clarence J. Swanton
Keyword(s):  
Abiotic Stress ◽  
Avoidance Response ◽  
Light Quality ◽  
Yield Loss ◽  
Shade Avoidance ◽  
Plant Tolerance ◽  
Relative Growth ◽  
Shoot Ratio ◽  
Root Shoot Ratio ◽  
The Impact

Previous studies have suggested that the reduction in the root/shoot ratio that accompanies the shade avoidance response may reduce the tolerance of individuals to subsequent nutrient or moisture limitations. In this work, we examined the impact of the shade avoidance response on maize seedling growth and development and the response of these plants to a subsequent abiotic stress. Seedlings were grown in a field fertigation system under two light quality environments, ambient and a low red to far-red ratio, which were designed to simulate weed-free and weedy conditions, respectively. This system also enabled the controlled restriction of water and nutrients, which reduced the relative growth rate of the crop and created a secondary stress. Results of this study indicate that, while the shade avoidance response did reduce the root/shoot ratio in maize, this effect did not reduce plant tolerance to subsequent abiotic stress. Rather, the apparent additivity or synergism of shade avoidance and the secondary stressor on yield loss depended on whether the net effect of these two stressors was sufficiently large to shift the population toward the point where reproductive allometry was broken.

Effects of Single-seed Sowing on Root Growth, Root-shoot Ratio, and Yield inPeanut (Arachis hypogacaL.)

2013 ◽  
Vol 39 (12) ◽  
pp. 2228 ◽  
Author(s):  
Ye FENG ◽  
Feng GUO ◽  
Bao-Long LI ◽  
Jing-Jing MENG ◽  
Xin-Guo LI ◽  
...  
Keyword(s):  
Root Growth ◽  
Single Seed ◽  
Shoot Ratio ◽  
Root Shoot Ratio ◽  
Seed Sowing

scholarly journals A Survey of Electromagnetic Influence on UAVs from an EHV Power Converter Stations and Possible Countermeasures

Electronics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 701
Author(s):  
Yanchu Li ◽  
Qingqing Ding ◽  
Keyue Li ◽  
Stanimir Valtchev ◽  
Shufang Li ◽  
...  
Keyword(s):  
Electromagnetic Interference ◽  
Wide Spectrum ◽  
Electromagnetic Emission ◽  
Power Converter ◽  
Electromagnetic Environment ◽  
Communication Circuits ◽  
Electromagnetic Emissions ◽  
Surrounding Space ◽  
Extra High Voltage ◽  
The Impact

It is inevitable that high-intensity, wide-spectrum electromagnetic emissions are generated by the power electronic equipment of the Extra High Voltage (EHV) power converter station. The surveillance flight of Unmanned Aerial Vehicles (UAVs) is thus, situated in a complex electromagnetic environment. The ubiquitous electromagnetic interference demands higher electromagnetic protection requirements from the UAV construction and operation. This article is related to the UAVs patrol inspections of the power line in the vicinity of the EHV converter station. The article analyzes the electromagnetic interference characteristics of the converter station equipment in the surrounding space and the impact of the electromagnetic emission on the communication circuits of the UAV. The anti-electromagnetic interference countermeasures strive to eliminate or reduce the threats of electromagnetic emissions on the UAV’s hardware and its communication network.

scholarly journals The Impact of Fluid Loss and Carbohydrate Consumption during Exercise, on Young Cyclists’ Fatigue Perception in Relation to Training Load Level

2021 ◽  
Vol 18 (6) ◽  
pp. 3282
Author(s):  
Leonardo Cesanelli ◽  
Berta Ylaitė ◽  
Giuseppe Messina ◽  
Daniele Zangla ◽  
Stefania Cataldi ◽  
...  
Keyword(s):  
Perceived Exertion ◽  
Wide Spectrum ◽  
Load Level ◽  
Training Load ◽  
Fluid Loss ◽  
Young Athletes ◽  
Carbohydrate Consumption ◽  
Significant Difference ◽  
Training Impulse ◽  
The Impact

High-level young athletes need to face a wide spectrum of stressors on their journey to élite categories. The aims of the present study are (i) to evaluate session rate of perceived exertion (sRPE) at different training impulse (TRIMP) categories and the correlations between these two variables and, (ii) evaluate the correlations between sRPE, fluid loss, and carbohydrate consumption during exercise. Data on Edward’s TRIMP, sRPE, body mass loss pre- and post- exercise (∆), and carbohydrate consumption (CHO/h) during exercise have been acquired from eight male junior cyclists during a competitive season. One-way ANOVA and correlation analysis with linear regression have been performed on acquired data. sRPE resulted in a significant difference in the three TRIMP categories (p < 0.001). sRPE resulted in being very largely positively associated with TRIMP values (p < 0.001; R = 0.71). ∆ as well as CHO/h was largely negatively related with sRPE in all TRIMP categories (p < 0.001). The results confirmed the role of fluid balance and carbohydrate consumption on the perception of fatigue and fatigue accumulation dynamics independently from the training load. Young athletes’ training load monitoring and nutritional-hydration support represent important aspects in athlete’s exercise-induced fatigue management.

scholarly journals Acute Management Should Be Optimized in Patients with Less Specific Stroke Symptoms: Findings from a Retrospective Observational Study

2021 ◽  
Vol 10 (5) ◽  
pp. 1143
Author(s):  
Simona Halúsková ◽  
Roman Herzig ◽  
Dagmar Krajíčková ◽  
Abduljabar Hamza ◽  
Antonín Krajina ◽  
...  
Keyword(s):  
Wide Spectrum ◽  
Intravenous Thrombolysis ◽  
National Institutes Of Health ◽  
Vascular Territory ◽  
Anterior Circulation ◽  
Point Increase ◽  
Single Center Study ◽  
Mouth Corner ◽  
Specific Symptoms ◽  
The Impact

Anterior circulation stroke (ACS) is associated with typical symptoms, while posterior circulation stroke (PCS) may cause a wide spectrum of less specific symptoms. We aim to assess the correlation between the initial presentation of acute ischemic stroke (AIS) symptoms and the treatment timeline. Using a retrospective, observational, single-center study, the set consists of 809 AIS patients treated with intravenous thrombolysis (IVT) and/or endovascular treatment (EVT). We investigate the impact of baseline clinical AIS symptoms and the affected vascular territory on recanalization times in patients treated with IVT only and EVT (±IVT). Regarding the IVT-only group, increasing the National Institutes of Health Stroke Scale (NIHSS) score on admission and speech difficulties are associated with shorter (by 1.59 ± 0.76 min per every one-point increase; p = 0.036, and by 24.56 ± 8.42 min; p = 0.004, respectively) and nausea/vomiting with longer (by 43.72 ± 13.13 min; p = 0.001) onset-to-needle times, and vertigo with longer (by 8.58 ± 3.84 min; p = 0.026) door-to-needle times (DNT). Regarding the EVT (±IVT) group, coma is associated with longer (by 22.68 ± 6.05 min; p = 0.0002) DNT, anterior circulation stroke with shorter (by 47.32 ± 16.89 min; p = 0.005) onset-to-groin time, and drooping of the mouth corner with shorter (by 20.79 ± 6.02 min; p = 0.0006) door-to-groin time. Our results demonstrate that treatment is initiated later in strokes with less specific symptoms than in strokes with typical symptoms.

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