scholarly journals Reactions of two xeric-congeneric species of Centaurea (Asteraceae) to soils with different pH values and iron availability

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12417
Author(s):  
Mateusz Wala ◽  
Jeremi Kołodziejek ◽  
Janusz Mazur ◽  
Alicja Cienkowska

Centaurea scabiosa L. and C. stoebe Tausch are known to co-exist naturally in two extremely different types of open dry habitats in the temperate zone, alkaline xerothermic grasslands and acidic dry grasslands. However, knowledge about their preferences to edaphic conditions, including soil acidity (pH), and iron (Fe) availability is scarce. Therefore, experimental comparison of soil requirements (acidic Podzol vs alkaline Rendzina) of these species was carried out. The study was designed as a pot experiment and conducted under field conditions. Fe availability was increased by application of Fe-HBED. Reactions of plants to edaphic conditions were determined using growth measurements, leaf morphometric measurements, chlorosis scoring, chlorophyll content and chlorophyll a fluorescence (OJIP) quantification as well as determination of element content (Ca, Mg, Fe, Mn, Zn and Cu). Growth and leaf morphometrical traits of the studied congeneric species were affected similarly by the soil type and differently by the chelate treatment. Increased availability of Fe in Rendzina contrasted the species, as treatment with 25 µmol Fe-HBED kg−1 soil promoted growth only in C. stoebe. Both species turned out to be resistant to Fe-dependent chlorosis which was also reflected in only minor changes in chlorophyll a fluorescence parameters. Both species showed relatively low nutritional demands. Surprisingly, Fe-HBED did not stimulate Fe acquisition in the studied species, nor its translocation along the root:shoot axis. Furthermore, contrary to expectations, C. scabiosa took up less Fe from the acidic than alkaline soil. C. scabiosa not only absorbed more Ca and Zn but also translocated greater amounts of these elements to shoots than C. stoebe. Both species acquired more Mg on Podzol than on Rendzina which suggests adaptation allowing avoidance of aluminum (Al) toxicity on acidic soils. Overall, it seems that C. scabiosa prefers alkaline soils, whilst C. stoebe prefers acidic ones.

2021 ◽  
Author(s):  
Kevin ROBE ◽  
max STASSEN ◽  
joseph CHAMIEH ◽  
philippe GONZALEZ ◽  
sonia HEM ◽  
...  

Iron (Fe) is a micronutrient essential for plant growth and development. Iron uptake in alkaline soil is a challenge for most plants. In this study, we investigated the role of the catechol coumarins fraxetin and esculetin in plant Fe acquisition and their Fe chelating properties. Mass spectrometry and capillary electrophoresis were used to characterize Fe-coumarin complexes. To understand the role of these complexes, genetic, molecular and biochemical approaches were deployed. We demonstrated that catechol coumarins are taken up by Arabidopsis thaliana root via an ATP dependent mechanism and that plants defective in IRT1 activity (the main high affinity Fe importer) or bHLH121 (a key regulator of Fe deficiency responses) can be complemented by exogenous supply of fraxetin and to a lesser extent of esculetin. We also showed that Fe and fraxetin can form stable complexes at neutral to alkaline pH that can be taken up by the plant. Overall, these results indicate that at high pH, fraxetin can improve Fe nutrition by directly transporting Fe(III) into the root, circumventing the FRO2/IRT1 system, in a similar way as phytosiderophores do in grasses. This strategy may explain how non-grass species can thrive in alkaline soils.


2002 ◽  
Vol 53 (9) ◽  
pp. 1019 ◽  
Author(s):  
M. D. Denton ◽  
D. R. Coventry ◽  
P. J. Murphy ◽  
J. G. Howieson ◽  
W. D. Bellotti

Inoculant rhizobia typically need to compete with naturalised soil populations of rhizobia to form legume nodules. We have used the polymerase chain reaction to test the ability of seed-inoculated rhizobia to compete with naturalised populations of rhizobia and form nodules on clover (Trifolium alexandrinum, T.�purpureum, and T. resupinatum) in alkaline soil. Clover rhizobia, Rhizobium leguminosarum bv. trifolii, were identified at the strain level using either a nif-specific RP01 primer or ERIC primers. Analysis of rhizobia isolated from nodules indicated that strain TA1 competed poorly for nodule occupancy at 2 field sites (Roseworthy and Mallala, South Australia), with the exception that it nodulated T. alexandrinum at a level of 39% at the Roseworthy site in the first year of the trial. Strains CC2483g and WSM409 successfully colonised nodules when inoculated onto a particular clover species (T. resupinatum and T. purpureum, respectively) in the first year of inoculation and persisted in the soil to form nodules in the following year. Nodules frequently contained naturalised strains of rhizobia, distinct from introduced commercial strains. Dominant isolates were specific to a field site and nodulated all 3 clover species in both years of the field trial, with each isolate occupying up to 19% of the total nodules at a field site. It was hypothesised that field isolates had a better alkaline soil tolerance conferring a greater ability to nodulate clovers under these edaphic conditions. The results indicate that soil populations of rhizobia may provide a significant constraint to the introduction of current Australian commercial clover rhizobia into alkaline soils, and a more profitable strategy may be to seek rhizobial inoculants that are adapted to these soils.


1935 ◽  
Vol 35 (2) ◽  
pp. 255-261 ◽  
Author(s):  
O. J. Cockerell

During the experimental comparison of different types of hot-water heating systems in a school at Easter 1934 about a thousand kata readings were taken. These were taken mostly in pairs, one immediately after the other, and a third reading was taken only when the first two differed by more than about 10 per cent.


HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 756B-756
Author(s):  
M. Tagliavini ◽  
A.D. Rombolà ◽  
B. Marangoni

Pear rootstocks differ in tolerance to calcareous and alkaline soils. Roots of Fe-efficient dicots react to Fe-deficiency stress by strongly enhancing the Fe3+-reductase system, termed turbo-reductase, and by lowering the rhizosphere pH. In this study, we tested whether such adaptation mechanisms characterize pear and quince genotypes. Two trials were performed using micropropagated plants of three quince rootstocks (BA29, CTS212, and MC), three Pyrus communis rootstocks (OH × F51 and two selections obtained at Bologna Univ.: A28 and B21) and of two pear cultivars (Abbé Fétel and Bartlett, own-rooted). In the first trial, plants were grown in a nutrient solution with [Fe(+)] and without iron [Fe(–)] for 50 days. Their root iron-reducing capacity (IRC) was determined colorimetrically, using ferrozine and Fe-EDTA, and Fe uptake of Fe(+) plants was estimated. In the second trial, the rhizosphere pH of plants grown in an alkaline soil (pH in water = 8.3) was measured by a microelectrode. With the only exception of pears OH × F51 and A28, whose IRC was similar in Fe(+) and Fe(–) plants, the Fe-deficiency stress caused a significant decrease of the IRC. Among the Fe(–) plants, the two pear OH × F51 and A28 had higher IRC than the quince rootstocks and the cultivar Abbé F. When plants were pretreated with Fe, IRC was highest in the P. communis rootstocks (more than 50 nmol Fe2+/g fresh weight per h), intermediate in the own-rooted cultivars, and lowest in the quinces (<15 nmol Fe2+/g fresh weight per h). Fe uptake proved to be linearly and positively correlated with root Fe-reducing capacity (r = 0.91***). Rhizosphere pH, averaged over the first 2 cm from root tips, was highest in quince MC (7.2), intermediate in the other two quinces and in the cultivar Abbé F. (6.2–6.6) and lowest in the pear rootstocks and in the cultivar Bartlett (5.2–5.5). The results indicate that roots of pear and quinces do not increase their ability to reduce the iron under Fe-deficiency stress. The genotypical differential tolerance to iron chlorosis likely reflects differences in the standard reductase system and in the capacity of lowering the pH at soil/root interface. The determination of the root IRC appears very promising as a screening technique for selecting efficient Fe-uptake rootstocks.


2020 ◽  
Vol 70 (12) ◽  
pp. 4594-4600

The purpose of this study was to characterize some types of biomass wastes resulted from different activities such as: agriculture, forestry and food industry using thermogravimetric and ICP-MS analyses. Also, it was optimized an ICP-MS method for the determination of As, Cd and Pb from biomass ash samples. The ICP-MS analysis revealed that the highest concentration of metals (As, Cd, Pb) was recorded in the wood waste ash sample, also the thermogravimetric analysis indicated that the highest amount of ash was obtained for the same sample (26.82%). The biomass wastes mentioned in this study are alternative recyclable materials, reusable as pellets and briquettes. Keywords: ash, biomass, ICP-MS, minor elements, TG


2018 ◽  
Vol 69 (5) ◽  
pp. 1139-1144
Author(s):  
Iosif Lingvay ◽  
Adriana Mariana Bors ◽  
Livia Carmen Ungureanu ◽  
Valerica Stanoi ◽  
Traian Rus

For the purpose of using three different types of painting materials for the inner protection of the transformer vats, their behavior was studied under actual conditions of operation in the transformer (thermal stress in electro-insulating fluid based on the natural ester in contact with copper for electro-technical use and electro-insulating paper). By comparing determination of the content in furans products (HPLC technique) and gases formed (by gas-chromatography) in the electro-insulating fluid (natural ester with high oleic content) thermally aged at 130 �C to 1000 hours in closed glass vessels, it have been found that the presence the investigated painting materials lead to a change in the mechanism and kinetics of the thermo-oxidation processes. These changes are supported by oxygen dissolved in oil, what leads to decrease both to gases formation CO2, CO, H2, CH4, C2H4 and C2H6) and furans products (5-HMF, 2-FOL, 2 -FAL and 2-ACF). The painting materials investigated during the heat treatment applied did not suffer any remarkable structural changes affecting their functionality in the electro-insulating fluid based on vegetable esters.


2021 ◽  
Vol 97 (4) ◽  
Author(s):  
Lucas Dantas Lopes ◽  
Jingjie Hao ◽  
Daniel P Schachtman

ABSTRACT Soil pH is a major factor shaping bulk soil microbial communities. However, it is unclear whether the belowground microbial habitats shaped by plants (e.g. rhizosphere and root endosphere) are also affected by soil pH. We investigated this question by comparing the microbial communities associated with plants growing in neutral and strongly alkaline soils in the Sandhills, which is the largest sand dune complex in the northern hemisphere. Bulk soil, rhizosphere and root endosphere DNA were extracted from multiple plant species and analyzed using 16S rRNA amplicon sequencing. Results showed that rhizosphere, root endosphere and bulk soil microbiomes were different in the contrasting soil pH ranges. The strongest impact of plant species on the belowground microbiomes was in alkaline soils, suggesting a greater selective effect under alkali stress. Evaluation of soil chemical components showed that in addition to soil pH, cation exchange capacity also had a strong impact on shaping bulk soil microbial communities. This study extends our knowledge regarding the importance of pH to microbial ecology showing that root endosphere and rhizosphere microbial communities were also influenced by this soil component, and highlights the important role that plants play particularly in shaping the belowground microbiomes in alkaline soils.


Medicina ◽  
2021 ◽  
Vol 57 (7) ◽  
pp. 679
Author(s):  
Monica Iuliana Ungureanu ◽  
Liliana Sachelarie ◽  
Radu Ciorap ◽  
Bogdan Aurelian Stana ◽  
Irina Croitoru ◽  
...  

Background and Objectives: Different types of food introduced gradually in the diet will expose children to different food allergens, increasing the chance of developing allergic diseases. The aim of our study was to determine if allergen-specific IgE values can influence, depending on the diet, the prediction of remission of urticaria in children. Materials and Methods: This prospective study was conducted in 132 patients diagnosed over two years with urticaria, admitted to “Sf. Maria” Clinical Pediatric Hospital Iaşi. Total IgE assay was performed by ELISA, and determination of specific serum IgE by the CLA System Quanti Scan method (Innogenetics, Heiden, Germany). Data were gathered and statistical analysis was performed using statistical software SPSS, using descriptive and inferential statistics. Results: The determination of specific IgE to food allergens was performed on a total of 132 cases. The values of specific IgE were positive for one or more food allergens in 84 patients (63.64%). The most common allergens involved were: cow’s milk in 33.3% cases, egg white in 22.6% cases, and hazelnuts in 11.9% cases. The specific IgE values for the different types of food included in our study had a predictive value for disease remission. Conclusions: The determination of specific IgE confirms the presence of a particular food allergen and may have predictive value for the future development of an allergic manifestation.


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