scholarly journals Interaction Between Sulfur and Iron in Plants

2021 ◽  
Vol 12 ◽  
Author(s):  
Stefania Astolfi ◽  
Silvia Celletti ◽  
Gianpiero Vigani ◽  
Tanja Mimmo ◽  
Stefano Cesco

It is well known that S interacts with some macronutrients, such as N, P, and K, as well as with some micronutrients, such as Fe, Mo, Cu, Zn, and B. From our current understanding, such interactions could be related to the fact that: (i) S shares similar chemical properties with other elements (e.g., Mo and Se) determining competition for the acquisition/transport process (SULTR transporter family proteins); (ii) S-requiring metabolic processes need the presence of other nutrients or regulate plant responses to other nutritional deficiencies (S-containing metabolites are the precursor for the synthesis of ethylene and phytosiderophores); (iii) S directly interacts with other elements (e.g., Fe) by forming complexes and chemical bonds, such as Fe-S clusters; and (iv) S is a constituent of organic molecules, which play crucial roles in plants (glutathione, transporters, etc.). This review summarizes the current state of knowledge of the interplay between Fe and S in plants. It has been demonstrated that plant capability to take up and accumulate Fe strongly depends on S availability in the growth medium in both monocots and dicot plants. Moreover, providing S above the average nutritional need enhances the Fe content in wheat grains, this beneficial effect being particularly pronounced under severe Fe limitation. On the other hand, Fe shortage induces a significant increase in the demand for S, resulting in enhanced S uptake and assimilation rate, similar to what happens under S deficiency. The critical evaluation of the recent studies on the modulation of Fe/S interaction by integrating old and new insights gained on this topic will help to identify the main knowledge gaps. Indeed, it remains a challenge to determine how the interplay between S and Fe is regulated and how plants are able to sense environmental nutrient fluctuations and then to adapt their uptake, translocation, assimilation, and signaling. A better knowledge of the mechanisms of Fe/S interaction might considerably help in improving crop performance within a context of limited nutrient resources and a more sustainable agriculture.

2021 ◽  
Vol 11 (10) ◽  
pp. 4417
Author(s):  
Veronica Vendramin ◽  
Gaia Spinato ◽  
Simone Vincenzi

Chitosan is a chitin-derived fiber, extracted from the shellfish shells, a by-product of the fish industry, or from fungi grown in bioreactors. In oenology, it is used for the control of Brettanomyces spp., for the prevention of ferric, copper, and protein casse and for clarification. The International Organisation of Vine and Wine established the exclusive utilization of fungal chitosan to avoid the eventuality of allergic reactions. This work focuses on the differences between two chitosan categories, fungal and animal chitosan, characterizing several samples in terms of chitin content and degree of deacetylation. In addition, different acids were used to dissolve chitosans, and their effect on viscosity and on the efficacy in wine clarification were observed. The results demonstrated that even if fungal and animal chitosans shared similar chemical properties (deacetylation degree and chitin content), they showed different viscosity depending on their molecular weight but also on the acid used to dissolve them. A significant difference was discovered on their fining properties, as animal chitosans showed a faster and greater sedimentation compared to the fungal ones, independently from the acid used for their dissolution. This suggests that physical–chemical differences in the molecular structure occur between the two chitosan categories and that this significantly affects their technologic (oenological) properties.


Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 571
Author(s):  
Willy Irakoze ◽  
Hermann Prodjinoto ◽  
Séverin Nijimbere ◽  
Jean Berchmans Bizimana ◽  
Joseph Bigirimana ◽  
...  

Salinity may strongly influence the interaction between plant roots and surrounding soil, but this has been poorly studied for sodium sulfate (Na2SO4). The aim of this study was to investigate the effect of sodium chloride (NaCl) and Na2SO4 salinities on the soil chemical properties as well as rice physiological- and yield-related parameters of two contrasted cultivars (V14 (salt-sensitive) and Pokkali (salt-resistant)). Pot experiments were conducted using soil and electrolyte solutions, namely NaCl and Na2SO4, inducing two electrical conductivity levels (EC: 5 or 10 dS m−1) of the soil solutions. The control treatment was water with salt-free tap water. Our results showed that soil pH increased under Na2SO4 salinity, while soil EC increased as the level of saline stress increased. Salinity induced an increase in Na+ concentrations on solid soil complex and in soil solution. NaCl reduced the stomatal density in salt-sensitive cultivar. The total protein contents in rice grain were higher in V14 than in Pokkali cultivar. Saline stress significantly affected all yield-related parameters and NaCl was more toxic than Na2SO4 for most of the studied parameters. Pokkali exhibited a higher tolerance to saline stress than V14, whatever the considered type of salt. It is concluded that different types of salts differently influence soil properties and plant responses and that those differences partly depend on the salt-resistance level of the considered cultivar.


2015 ◽  
Vol 1790 ◽  
pp. 13-18
Author(s):  
Shun Sasaki ◽  
Shailesh Madisetti ◽  
Vadim Tokranov ◽  
Michael Yakimov ◽  
Makoto Hirayama ◽  
...  

ABSTRACTGroup III-Sb compound semiconductors are promising materials for future CMOS circuits. Especially, In1-xGaxSb is considered as a complimentary p-type channel material to n-type In1-xGaxAs MOSFET due to the superior hole transport properties and similar chemical properties in III-Sb’s to those of InGaAs. The heteroepitaxial growth of In1-xGaxSb on Si substrate has significant advantage for volume fabrication of III-V ICs. However large lattice mismatch between InGaSb and Si results in many growth-related defects (micro twins, threading dislocations and antiphase domain boundaries); these defects also act as deep acceptor levels. Accordingly, unintentional doping in InGaSb films causes additional scattering, increase junction leakages and affects the interface properties. In this paper, we studied the correlations between of defects and hole carrier densities in GaSb and strained In1-xGaxSb quantum well layers by using various designs of metamorphic superlattice buffers.


Author(s):  
Lars Öhrström

The appearance of a diamond engagement ring in the long and convoluted love story between Botswana’s First Lady Detective, Mma Ramotswe, and the owner and brilliant mechanic of Tlokweng Road Speedy Motors, Mr J. L. B. Matekoni, seems to signal an end to this particular sub-plot, stretching over several volumes of Alexander McCall Smith’s bestselling and original series of crime novels (that we met in Chapter 1). However, a slight problem involving cubic zirconia is discovered, and the story lingers on until the next book in the series. Similar names for elements and their compounds are a nuisance in chemistry, but oft en arise historically, and zirconium is just one such example. Apart from the pure metal we have zircon and zirconia, all three of which have important applications. Zircon is zirconium silicate, with the formula ZrSiO4, and cubic zirconia is a special form of zirconium dioxide, ZrO2. The latter, as you may have guessed, is an excellent diamond substitute in, among other applications, engagement rings. We are not going to dwell on the details of the element zirconium, but you should know that within the Periodic Table it is located in the large middle chunk called the transition metals. You have probably heard of its cousin titanium, immediately above it, and a sibling, hafnium, straight down the ladder. Why do I call them siblings? Because in the Periodic Table elements in the same column tend to have similar chemical properties. In particular, in the family of transition metals in the central section containing 27 elements—each with a number of properties in common—the two lower elements in each column tend to be the most similar. The similar chemical properties of zirconium and titanium means that we can usually find zirconium where we mine the much more plentiful titanium, and also that once we have separated the titanium from zirconium there will be a small quantity of hafnium trailing along—an impurity that is much harder to get rid of. The sleek jeweller in Gaborone will not care if his fake diamonds contain trace levels of HfO2 mixed with the ZrO2.


Author(s):  
Marco Fontani ◽  
Mariagrazia Costa ◽  
Mary Virginia Orna

Within the period covered by Part II, 1789–1869, 37 true elements, almost all of them metals, were discovered. Prior to this time, about 14 metals had been discovered, excluding those that had been known from ancient times. The discovery of the elements during this period of interest is intimately related to the analytical methodologies available to chemists, as well as to a growing consciousness of just what an element is. Because these methods were also available to the less competent who may have lacked the skills to use them or the knowledge to interpret their results, their use also led to as many, if not more, erroneous discoveries in the same period. One can number among the major sources of error faulty interpretation of experimental data, the “rediscovery” of an already known element, sample impurities, very similar chemical properties (as in the case of the rare earths), the presence of an element in nature in very scarce or trace amounts, gross experimental errors, confusion of oxides and earths with their metals, and baseless dogmatic pronouncements by known “authorities” in the field. Antoine Laurent Lavoisier’s conceptualization of what constitutes an element was a radical break from the principles of alchemy. His stipulation that an element is a substance that cannot be further decomposed conferred an operational, pragmatic, concrete definition on what had previously been a more abstract concept. At the other end of the spectrum was the intuition of Dmitri Mendeleev who, contrary to the prevailing acceptance of Lavoisier’s concept, stressed the importance of retaining a more abstract, more fundamental sense of an element—an idea that in the long run enabled the development of the periodic table. What both men had in common is that they defined and named individual elements as those components of substances that could survive chemical change and whose presence in compounds could explain their physical and chemical properties. Mendeleev’s table has been immortalized in every chemistry classroom—and also concretely in Saint Petersburg, the city that saw most of his professional activity, by a spectacular building-sized model The analytical chemist depends on both of these concepts and indeed, analytical practice preceded Lavoisier’s concept by at least a century.


1979 ◽  
Vol 23 ◽  
pp. 157-161
Author(s):  
L. E. Miller ◽  
H. J. Abplanalp

For the past several years the Boeing Aerospace Company has been implementing advanced nondestructive chemical analysis methods to improve product reliability and reduce material inspection costs. Previous testing of incoming material for conformance to vendor test reports or of production materials for verification of alloy composition, had consisted of either time-consuming destructive testing or nondestructive chemical spot testing, which often was insensitive to differences between alloys of similar chemical properties. Beginning in 1974, development of EDXRF techniques was initiated to provide a rapid nondestructive analysis capability for both laboratory and factory use. For materials containing elements easily excited by EDXRF methods, costly destructive sampling and testing can be avoided. Generally, chips, wire, barstock, sheet or plate can be analyzed using an annular radioactive source. The uniformity of the X-ray flux diminishes sample geometry and surface roughness effects.


2000 ◽  
Vol 6 (S2) ◽  
pp. 206-207
Author(s):  
Huifang Xu

Because of similar chemical properties of the rare earth elements (Ree), whole series of the Ree may occur in natural Ree-bearing crystals. Relative concentration of the Ree may vary as the crystallization environments change. Electron energy-dispersive spectroscopy (EDS) associated with TEM is unable to resolve Ree and other coexistence elements, such as Ba nd Ti, because of peak overlap and energy resolution (∼ 150 eV) of EDS. Figure A indicate multiple peaks from Ce only. The Cu peaks are from Cu grid holding the specimen. Electron energy-loss spectroscopy (EELS) with energy resolution of < 1 eV is able to resolve all Ree in natural Ree-bearing crystals.Natural carbonate crystals from a Ree ore deposit were investigated by using EELS associated with field emission-gun (FEG) TEM. The crystals are in a chemical series of BaCO3 - Ree(CO3)F [1]. In Figure B, EEL spectra A and B are from Ce-rich and La-rich bastnaesite (Ree(CO3)F), respectively; spectrum D is from cordylite (BaCO3 (Ree(CO3)F); spectrum E is from huanghoite (BaCO3 Ree(CO3)F), spectrum F is from BaCO3; spectrum C is from an unknown Ree-rich phase.


1994 ◽  
Vol 45 (7) ◽  
pp. 1517 ◽  
Author(s):  
GJ Blair ◽  
M Dana ◽  
R Lefroy

In many parts of the world it has become more economical to use triple superphosphate (TSP) rather than single superphosphate (SSP) as a pasture fertilizer where only P deficiency exists. Coating TSP with elemental S is an attractive alternative to SSP for situations where P and S deficiency exists. A pot experiment was conducted on an S deficient Aquic Haplustalf soil to compare the ability of gypsum (G) and S coated TSP to supply S to a ryegrass/white clover pasture over 14 repeated harvests over a 96 week period. The adhesives used to coat S to TSP were UNE1, UNE3, UNE2 and a commercial product (HF). The reverse dilution 35S technique was used to calculate fertilizer S uptake. Total yields were highest with G and UNE1. Total fertilizer S recovery by the pasture was 64.4% for G and 52.3% and 52.9% for UNEl and UNE3 respectively. These amounts were significantly higher than from UNE2 or HF. The time course of fertilizer S release varied between products and shows that bonding method can affect S availability from S coated TSP products.


1994 ◽  
Vol 50 (3) ◽  
Author(s):  
A. B. Du Toit

The rise and current state of New Testament research in South Africa: Part 3 - A critical evaluation First the pros and cons of the South African emphasis on methodology arw discussed. On the positive side a much greater sensitivity for methodological austerity has been developed. On the negative side New Testament research has not contributed enough towards serving theology and the church at large. In dealing with the problem of relevancy in the socio-political field, it is acknowledged that more should be done, without putting the specific character of New Testament studies in jeopardy. The burning issue of the relationship between faith and reason should be tackled. The correct approach seems to be respecting the tension between these two entities, while at the same time working and striving towards closing the gap between them.


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