Alleviatory effects of Silicon on the morphology, physiology, and antioxidative mechanisms of wheat (Triticum aestivum L.) roots under cadmium stress in acidic nutrient solutions

AbstractSilicon (Si), as a quasi-essential element, has a vital role in alleviating the damaging effects of various environmental stresses on plants. Cadmium (Cd) stress is severe abiotic stress, especially in acidic ecological conditions, and Si can demolish the toxicity induced by Cd as well as acidic pH on plants. Based on these hypotheses, we demonstrated 2-repeated experiments to unfold the effects of Si as silica gel on the root morphology and physiology of wheat seedling under Cd as well as acidic stresses. For this purpose, we used nine treatments with three levels of Si nanoparticles (0, 1, and 3 mmol L−1) derived from sodium silicate (Na2SiO3) against three concentrations of Cd (0, 50, and 200 µmol L−1) in the form of cadmium chloride (CdCl2) with three replications were arranged in a complete randomized design. The pH of the nutrient solution was adjusted at 5. The averages of three random replications showed that the mutual impacts of Si and Cd in acidic pH on wheat roots depend on the concentrations of Si and Cd. The collective or particular influence of low or high levels of Si (1 or 3 mM) and acidic pH (5) improved the development of wheat roots, and the collective influence was more significant than that of a single parallel treatment. The combined effects of low or high concentrations of Cd (50 or 200 µM) and acidic pH significantly reduced root growth and biomass while increased antioxidants, and reactive oxygen species (ROS) contents. The incorporation of Si (1 or 3 mmol L−1) in Cd-contaminated acidic nutrient solution promoted the wheat root growth, decreased ROS contents, and further increased the antioxidants in the wheat roots compared with Cd single treatments in acidic pH. The demolishing effects were better with a high level of Si (3 mM) than the low level of Si (1 Mm). In conclusion, we could suggest Si as an effective beneficial nutrient that could participate actively in several morphological and physiological activities of roots in wheat plants grown under Cd and acidic pH stresses.

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Root growth of lupins is more sensitive to waterlogging than wheat

Functional Plant Biology ◽

10.1071/fp11148 ◽

2011 ◽

Vol 38 (11) ◽

pp. 910 ◽

Cited By ~ 12

Author(s):

Helen Bramley ◽

Stephen D. Tyerman ◽

David W. Turner ◽

Neil C. Turner

Keyword(s):

Root Growth ◽

Oxygen Deficiency ◽

Triticum Aestivum L ◽

Wheat Root ◽

Lupinus Luteus ◽

Apical Region ◽

Basal Region ◽

Yellow Lupin ◽

Wheat Roots ◽

Root Death

In south-west Australia, winter grown crops such as wheat and lupin often experience transient waterlogging during periods of high rainfall. Wheat is believed to be more tolerant to waterlogging than lupins, but until now no direct comparisons have been made. The effects of waterlogging on root growth and anatomy were compared in wheat (Triticum aestivum L.), narrow-leafed lupin (Lupinus angustifolius L.) and yellow lupin (Lupinus luteus L.) using 1 m deep root observation chambers. Seven days of waterlogging stopped root growth in all species, except some nodal root development in wheat. Roots of both lupin species died back progressively from the tips while waterlogged. After draining the chambers, wheat root growth resumed in the apical region at a faster rate than well-drained plants, so that total root length was similar in waterlogged and well-drained plants at the end of the experiment. Root growth in yellow lupin resumed in the basal region, but was insufficient to compensate for root death during waterlogging. Narrow-leafed lupin roots did not recover; they continued to deteriorate. The survival and recovery of roots in response to waterlogging was related to anatomical features that influence internal oxygen deficiency and root hydraulic properties.

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Temperature and pH of the nutrient solution on wheat primary root growth

Scientia Agricola ◽

10.1590/s0103-90162004000300013 ◽

2004 ◽

Vol 61 (3) ◽

pp. 313-318 ◽

Cited By ~ 2

Author(s):

Carlos Eduardo de Oliveira Camargo ◽

Antonio Wilson Penteado Ferreira Filho ◽

Marcus Vinicius Salomon

Keyword(s):

Root Growth ◽

Nutrient Solution ◽

Primary Root ◽

Growth Period ◽

Triticum Aestivum L ◽

Solution Temperature ◽

Stages Of Development ◽

Primary Root Growth ◽

Temperature And Growth ◽

Nutrient Solutions

Primary root growth is very important for wheat (Triticum aestivum L.) crop in upland conditions in the State of São Paulo. Fourteen wheat genotypes (mutant lines and cultivars) were evaluated for primary root growth during 7 and 15 days of development in complete and aerated nutrient solutions, in the laboratory. In the first experiment, solutions with three pH values (4.0, 5.0 and 6.0) at constant temperature (24 ± 1°C), and in the second experiment, solutions with the same pH (4.0) but with three temperatures (18°C ± 1°C, 24°C ± 1°C and 30°C ± 1°C) were used. High genetic variability was observed among the evaluated genotypes in relation to primary root growth in the first stages of development in nutrient solutions independent of pH, temperature and growth period. Genotypes 6 (BH-1146) and 13 (IAC-17), tolerant to Al3+ showed genetic potential for root growth in the first stages of development (7 and 15 days), regardless of nutrient solution temperature and pH. Genotypes 14 (IAC-24 M), 15 (IAC-24), 17 (MON"S" / ALD "S") ´ IAC-24 M2, 18 (MON"S" / ALD "S") ´ IAC-24 M3 and 24 (KAUZ"S" / IAC-24 M3), tolerant to Al3+, showed reduced root growth under the same conditions.

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The Effect of Different Fertilization Treatments on Wheat Root Depth and Length Density Distribution in a Long-Term Experiment

Agronomy ◽

10.3390/agronomy10091355 ◽

2020 ◽

Vol 10 (9) ◽

pp. 1355

Author(s):

Pavel Svoboda ◽

Gabriela Kurešová ◽

Ivana Raimanová ◽

Eva Kunzová ◽

Jan Haberle

Keyword(s):

Density Distribution ◽

Root Length ◽

Root Length Density ◽

Resource Depletion ◽

Triticum Aestivum L ◽

Wheat Root ◽

Root Depth ◽

Wheat Roots ◽

Climate Conditions ◽

Long Term Experiment

The purpose of this study was to determine the effect of sixty years of contrasting fertilization treatments on the roots of winter wheat (Triticum aestivum L.) at sites with different soil and climate conditions. The depth and length density distribution of the wheat roots were determined between 2014 and 2016 in a crop rotation experiment established in 1955 at three sites: Lukavec, Čáslav, and Ivanovice (Czech Republic). Three fertilization treatments were examined: Zero fertilization (N0), organic (ORG) fertilization, and mineral (MIN) fertilization. The fertilization, site, and year all had a significant effect on the total root length (TRL). The average TRL per square meter reached 30.2, 37.0, and 46.1 km with the N0, ORG, and MIN treatments at Lukavec, respectively, which was the site with the lightest soil and the coldest climate. At Čáslav and Ivanovice (warmer sites with silt and loamy soils), the average TRL per square meter reached 41.2, 42.4, and 47.7 km at Čáslav and 49.2, 55.3, and 62.9 km at Ivanovice with the N0, MIN, and ORG treatments, respectively. The effect of fertilization on the effective root depth (EfRD), the depth at which the root length density dropped below 2.0 cm cm−3, was significant, while the maximum root depth (RMD) was only marginally affected. With the sites and years averaged, the MIN-treated plants showed a greater EfRD (102.2 cm) in comparison to the N0 (81.8 cm) and ORG (93.5 cm) treatments. The N0 treatment showed no signs of an adaptive reaction to the root system, with potential improvement for nutrient acquisition, while optimal fertilization contributed to the potential for resource depletion from the soil profile.

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Modeling root system growth around obstacles

Scientific Reports ◽

10.1038/s41598-020-72557-8 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Wencheng Jin ◽

Jayde Aufrecht ◽

Fernando Patino-Ramirez ◽

Heidy Cabral ◽

Chloé Arson ◽

...

Keyword(s):

Root Growth ◽

Root System ◽

Time Lapse ◽

Wheat Root ◽

Root System Architecture ◽

Main Axis ◽

Wheat Roots ◽

Wheat Seedlings ◽

Proposed Model ◽

3D Printed

Abstract State-of-the-Art models of Root System Architecture (RSA) do not allow simulating root growth around rigid obstacles. Yet, the presence of obstacles can be highly disruptive to the root system. We grew wheat seedlings in sealed petri dishes without obstacle and in custom 3D-printed rhizoboxes containing obstacles. Time-lapse photography was used to reconstruct the wheat root morphology network. We used the reconstructed wheat root network without obstacle to calibrate an RSA model implemented in the R-SWMS software. The root network with obstacles allowed calibrating the parameters of a new function that models the influence of rigid obstacles on wheat root growth. Experimental results show that the presence of a rigid obstacle does not affect the growth rate of the wheat root axes, but that it does influence the root trajectory after the main axis has passed the obstacle. The growth recovery time, i.e. the time for the main root axis to recover its geotropism-driven growth, is proportional to the time during which the main axis grows along the obstacle. Qualitative and quantitative comparisons between experimental and numerical results show that the proposed model successfully simulates wheat RSA growth around obstacles. Our results suggest that wheat roots follow patterns that could inspire the design of adaptive engineering flow networks.

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Surface application of lime ameliorates subsoil acidity and improves root growth and yield of wheat in an acid soil under no-till system

Scientia Agricola ◽

10.1590/s0103-90162006000500013 ◽

2006 ◽

Vol 63 (5) ◽

pp. 502-509 ◽

Cited By ~ 33

Author(s):

Eduardo Fávero Caires ◽

José Cristovão Leal Corrêa ◽

Susana Churka ◽

Gabriel Barth ◽

Fernando José Garbuio

Keyword(s):

Root Growth ◽

Grain Yield ◽

Acid Soil ◽

Triticum Aestivum L ◽

Wheat Root ◽

Growth And Yield ◽

No Till ◽

Subsurface Layers ◽

Crop Root

Crop root growth and grain yield can be affected by chemical modifications in the soil profile due to surface lime application. A field trial was carried out on a loamy dystrophic Typic Hapludox at Ponta Grossa, State of Paraná, Brazil, to evaluate root growth and grain yield of wheat (Triticum aestivum L. cv. CD 104, moderately susceptible to Al), about 10 years after surface liming (0, 2, 4, and 6 Mg ha-1) and three years after surface re-liming (0 and 3 Mg ha-1), in a long-term no-till cultivation system. Soil acidity limited wheat root growth and yield severely, probably as a result of extended water deficits during the vegetative stage. Surface liming caused increases up to 66% in the root growth (0-60 cm) and up to 140% in the grain yield. Root density and grain yield were correlated positively with soil pH and exchangeable Ca2+, and negatively with exchangeable Al3+ and Al3+ saturation, in the surface and subsurface layers.

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High-affinity potassium transport into wheat roots involves sodium - a role for HKT1?

Functional Plant Biology ◽

10.1071/pp01034 ◽

2001 ◽

Vol 28 (7) ◽

pp. 645

Author(s):

Donna E. Hayes ◽

F. Andrew Smith ◽

N. Alan Walker

Keyword(s):

Wheat Seedling ◽

Wheat Root ◽

Uptake Mechanism ◽

Wheat Roots ◽

High Ph ◽

High Affinity ◽

Site Selectivity ◽

Seedling Roots ◽

Wheat Seedling Roots ◽

K Transport

When a high-affinity K + transporter, HKT1, was cloned from the roots of K + -starved wheat and characterized, it seemed that the wheat high-affinity K + -uptake mechanism had been found. We review the present status of HKT1 as a putative component of the wheat root high-affinity mechanism, concluding that its role remains unclear, as it also does in barley. We describe a new attempt to find its role. High-affinity K + transport in K + -starved wheat seedling roots was studied by measuring K + -evoked depolarization. A single dominant transport system was shown to carry K + , Rb + and Cs + , with a binding site selectivity of about 1:1:0.15, respectively. We showed that the small effect of 1 mM Na + on K + -evoked depolarization could be inhibition under some conditions and stimulation under others. We confirmed that the effect of 1 mM Na + was to raise the K + affinity and to reduce transport velocity. In 0 Na + , high pH greatly reduced the K + -affinity, but in 1 mM Na + , high pH had no effect. So, in a given test, the effect of Na + was to increase or decrease K + -evoked depolarization, depending on the test [K + ] and the pH. We discuss simplified, but plausible, kinetic models for this interaction of pH and Na + . The simplest model includes a K + symporter driven by H + or Na + depending on their relative concentrations and affinities, with random binding order for the two possible driver ions. This symporter would differ from HKT1 in its selectivity for Rb + vs K + and in its inability to carry Na + alone. No role has been found for a symporter resembling HKT1 as it is presently characterized by heterologous expression.

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Effectiveness of complex inoculation of spring wheat with N[2] -fi xing bacteria Azospirillum brasilense and mold-antagonist Chaetomium cochliodes

Agricultural science and practice ◽

10.15407/agrisp1.03.057 ◽

2014 ◽

Vol 1 (3) ◽

pp. 57-61

Author(s):

E. Kopylov

Keyword(s):

Spring Wheat ◽

Root Zone ◽

Wheat Root ◽

Root Surface ◽

Atmospheric Nitrogen ◽

Rhizospheric Soil ◽

Chain Reaction ◽

Wheat Roots ◽

Chlorophyll A And B ◽

Polymerase Chain

Aim. To study the specifi cities of complex inoculation of spring wheat roots with the bacteria of Azospirillum genus and Chaetomium cochliodes Palliser 3250, and the isolation of bacteria of Azospirillum genus, capable of fi xing atmospheric nitrogen, from the rhizospheric soil, washed-off roots and histoshere. Materials and meth- ods. The phenotypic features of the selected bacteria were identifi ed according to Bergi key. The molecular the polymerase chain reaction and genetic analysis was used for the identifi cation the bacteria. Results. It has been demonstrated that during the introduction into the root system of spring wheat the strain of A. brasilensе 102 actively colonizes rhizospheric soil, root surface and is capable of penetrating into the inner plant tissues. Conclusions. The soil ascomucete of C. cochliodes 3250 promotes better settling down of Azospirillum cells in spring wheat root zone, especially in plant histosphere which induces the increase in the content of chlorophyll a and b in the leaves and yield of the crop.

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Effect of 24-epibrassinolide on localization of ABA, AZP, and dehydrins in wheat plant roots during dehydration

Biomics ◽

10.31301/2221-6197.bmcs.2020-20 ◽

2020 ◽

Vol 12 (3) ◽

pp. 329-336

Author(s):

A.R. Lubyanova ◽

F.M. Shakirova ◽

M.V. Bezrukova

Keyword(s):

Triticum Aestivum ◽

Wheat Germ ◽

Wheat Plant ◽

Triticum Aestivum L ◽

Immunohistochemical Localization ◽

Plant Roots ◽

Wheat Roots ◽

Wheat Seedlings ◽

Apoplastic Barrier ◽

Protective Proteins

We studied the immunohistochemical localization of abscisic acid (ABA), wheat germ agglutinin (WGA) and dehydrins in the roots of wheat seedlings (Triticum aestivum L.) during 24-epibrassinolide-pretreatment (EB-pretreatment) and PEG-induced dehydration. It was found coimmunolocalization of ABA, WGA and dehydrins in the cells of central cylinder of basal part untreated and EB-pretreated roots of wheat seedlings under normal conditions and under osmotic stress. Such mutual localization ABA and protective proteins, WGA and dehydrins, indicates the possible effect of their distribution in the tissues of EB-pretreated wheat roots during dehydration on the apoplastic barrier functioning, which apparently contributes to decrease the water loss under dehydration. Perhaps, the significant localization of ABA and wheat lectin in the metaxylem region enhances EB-induced transport of ABA and WGA from roots to shoots under stress. It can be assumed that brassinosteroids can serve as intermediates in the realization of the protective effect of WGA and wheat dehydrins during water deficit.

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Influence of Atomization Nozzles and Spraying Intervals on Growth, Biomass Yield, and Nutrient Uptake of Butter-Head Lettuce under Aeroponics System

Agronomy ◽

10.3390/agronomy11010097 ◽

2021 ◽

Vol 11 (1) ◽

pp. 97

Author(s):

Mazhar H. Tunio ◽

Jianmin Gao ◽

Imran A. Lakhiar ◽

Kashif A. Solangi ◽

Waqar A. Qureshi ◽

...

Keyword(s):

Root Growth ◽

Nutrient Uptake ◽

Nutrient Solution ◽

Biomass Yield ◽

Chemical Properties ◽

Cultivated Plants ◽

Growth Ratio ◽

Shoot Ratio ◽

Droplet Sizes ◽

Root To Shoot Ratio

The atomized nutrient solution droplet sizes and spraying intervals can impact the chemical properties of the nutrient solution, biomass yield, root-to-shoot ratio and nutrient uptake of aeroponically cultivated plants. In this study, four different nozzles having droplet sizes N1 = 11.24, N2 = 26.35, N3 = 17.38 and N4 = 4.89 µm were selected and misted at three nutrient solution spraying intervals of 30, 45 and 60 min, with a 5 min spraying time. The measured parameters were power of hydrogen (pH) and electrical conductivity (EC) values of the nutrient solution, shoot and root growth, ratio of roots to shoots (fresh and dry), biomass yield and nutrient uptake. The results indicated that the N1 presented significantly lower changes in chemical properties than those of N2, N3 and N4, resulting in stable lateral root growth and increased biomass yield. Also, the root-to-shoot ratio significantly increased with increasing spraying interval using N1 and N4 nozzles. The N1 nozzle also revealed a significant effect on the phosphorous, potassium and magnesium uptake by the plants misted at proposed nutrient solution spraying intervals. However, the ultrasonic nozzle showed a nonsignificant effect on all measured parameters with respect to spraying intervals. In the last, this research experiment validates the applicability of air-assisted nozzle (N1) misting at a 30-min spraying interval and 5 min of spraying time for the cultivation of butter-head lettuce in aeroponic systems.

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