Sulfur Uptake Research Articles

Sulfur-Oxidizing Bacteria From Coal Mine Enhance Sulfur Nutrition in Pigeonpea (Cajanus cajan L.)

The present investigation was carried out to isolate, identify, and characterize sulfur-oxidizing bacteria (SOB) from coal mines and to evaluate the efficient strains for their ability to influence plant growth and S uptake in pigeonpea. Thirteen bacterial isolates belonging to Stenotrophomonas maltophilia (2), Stenotrophomonas pavanii (2), Rhizobium pusense (5), Bacillus velezensis (2), and Paenibacillus massiliensis (2) were obtained. Among these, seven strains that could reduce the pH of thiosulfate broth were further characterized for sulfur oxidation, plant growth-promoting (PGP) attributes, and in planta studies. Among the seven strains characterized, maximum sulfate ion was recorded for S. maltophilia DRC-18-7A (311.43 mg L−1) closely followed by S. pavanii DRC-18-7B (273.44 mg L−1) and S. maltophilia DRC-18-10 (265.75 mg L−1) after 21 days of inoculation. Among the PGP attributes quantified, maximum P solubilization was recorded in case of S. maltophilia DRC-18-7A (24.39 μg ml−1), while highest siderophore production and IAA production were recorded in S. maltophilia DRC-18-10 (14.25%) and R. pusense DRC-18-25 (15.21 μg ml−1), respectively. S. maltophilia DRC-18-7A closely followed by S. pavanii DRC-18-7B outperformed others in enhancing seed germination (%) and vigour indices. Results clearly indicated that microbial inoculants colonized the plant roots and developed biofilm on the root surface. It was further observed that plants treated with microbial inoculants induce an early formation of secondary and tertiary roots in the pigeonpea compared to the untreated control which was further confirmed by assessing the root architecture using the root scanner. Inoculation of these two strains to pigeonpea significantly enhanced plant growth parameters, the activity of reactive oxygen scavenging (ROS) enzymes, and accumulation of flavonoids, carotenoids, and proline both under sterilized and non-sterilized growth medium (sand and soil in 1:3 ratio). The application of microbial inoculants significantly increased the uptake of nitrogen, phosphorus, potassium, and sulfur in plant shoots. Further, transcript level of phosphate, potassium, and sulfur transporter genes significantly increases upon microbial inoculation leading to increased uptake and translocation of P, K, and S in the pigeonpea. The results indicate that S. maltophilia DRC-18-7A and S. pavanii DRC-18-7B could be recommended as inoculants for pigeonpea to improve its growth and sulfur nutrition.

Biomass production and uptake of sulfur, chromium and micronutrients by Tanzania guinea grass grown with sulfur and chromium.

Soil contamination caused by improper waste disposal can affect plant growth. Tropical forage plants have rapid growth, high biomass production and vigorous regrowth. Chromium (Cr) is one of the most common contaminants in the environment. Sulfur (S) is a nutrient involved in various cell detoxification processes. The objective was to assess the effects of excess Cr on biomass production and concentrations of this metal, S and cationic micronutrients, under conditions of varying supply of S for Tanzania guinea grass. The experiment was conducted in randomized complete blocks in a 3 × 4 factorial scheme, corresponding to three levels of S (0.1, 1.9 and 3.7mmol L-1) and four levels of Cr (0.0, 0.5, 1.0 and 2.0mmol L-1) in three replicates. Root surface area, shoot and root biomass production, concentrations of total S, sulfate-S, Cr and cationic micronutrients, and Cr transport factor were determined. S level of 1.9mmol L-1 reduced the toxicity by Cr in Tanzania guinea grass, expressed by the higher shoot and root dry weight production, greater stability in the cellular concentration of sulfate-S and higher concentrations of micronutrients. It was concluded that the high availability of S reduced the toxicity by Cr(VI) in Tanzania guinea grass, expressed by the higher shoot and root dry weight production, greater stability in the cellular concentration of sulfate-S and higher concentration of micronutrients in the grass shoots.

Influence of Nutrient and Weed Management on Zn and S Uptake by Crop and weeds in Mustard

A field experiment was conducted in rabi season 2018-2019 and 2019-2020 at Research farm of Bihar Agricultural College, Sabour to study the effect of nutrient levels and weed management on zinc and sulphur uptake by crop and weeds in mustard. This experiment consisted of three nutrient levels (N1-soil test-based recommended dose of fertilizer (RDF), N2-100 % RDF, N3-125 % RDF) in main plot; eight weed management practices (W1-Weedy, W2- Hand weeding (HW), W3-pendimethalin, W4-pendimethalin followed by (fb) quizalofop, W5-pendimethalin fb clodinafop, W6-oxyflourfen, W7-oxyflourfen fb quizalofop, W8-oxyflourfen fb clodinafop) in sub plots, was laid out in split plot design. Results indicated that in both the years 2018-19 and 2019-20, hand weeding at 25 and 50 DAS along with 125% RDF exhibited minimum Zn uptake by weeds. Among herbicides, application of pendimethalin 30 EC 1.0 kg a.i. ha-1 PE fb quizalofop 5 EC 60 g a.i. ha-1 PoE along with 125% RDF exhibited lowest Zn uptake by weeds. In both the years 2018-19 and 2019-20, hand weeding at 25 and 50 DAS along with 125% RDF recorded minimum S uptake by weeds. Lowest S uptake by weeds was noted under application of pendimethalin 30 EC 1.0 kg a.i. ha-1 PE fb quizalofop 5 EC 60 g a.i. ha-1 PoE along with 125% RDF. In 2018-2019, Zn uptake by mustard was maximum under 125% RDF being at par with soil test-based RDF and was superior over 100% RDF. Hand weeding at 25 and 50 DAS exhibited highest Zn uptake by mustard. Maximum Zn uptake by mustard was noted with pendimethalin 30 EC 1.0 kg a.i. ha-1 PE fb quizalofop 5 EC 60 g a.i. ha-1 PoE. In 2019-2020, hand weeding at 25 and 50 DAS along with 125% RDF exhibited highest Zn uptake by mustard. Among herbicides, application of pendimethalin 30 EC @ 1.0 kg a.i. ha-1 PE fb clodinafop 15 WP @ 60 g a.i. ha-1 PoE along with 125% RDF registered highest Zn uptake by mustard. In 2018-2019, hand weeding at 25 and 50 DAS exhibited highest S uptake by mustard. Maximum S uptake by mustard was recorded with pendimethalin 30 EC 1.0 kg a.i. ha-1 PE fb quizalofop 5 EC 60 g a.i. ha-1 PoE. In 2019-2020, although hand weeding at 25 and 50 DAS along with 125% RDF exhibited highest S uptake by mustard, however, pendimethalin 30 EC 1.0 kg a.i. ha-1 PE fb quizalofop 5 EC 60 g a.i. ha-1 PoE along with 125% RDF registered highest S uptake by mustard.

Assessing the Effect of Silicon Supply on Root Sulfur Uptake in S-Fed and S-Deprived Brassica napus L.

Silicon (Si) is known to alleviate many nutritional stresses. However, in Brassica napus, which is a highly S-demanding species, the Si effect on S deficiency remains undocumented. The aim of this study was to assess whether Si alleviates the negative effects of S deficiency on Brassica napus and modulates root sulfate uptake capacity and S accumulation. For this, Brassica napus plants were cultivated with or without S and supplied or not supplied with Si. The effects of Si on S content, growth, expression of sulfate transporter genes (BnaSultr1.1; BnaSultr1.2) and sulfate transporters activity in roots were monitored. Si supply did not mitigate growth or S status alterations due to S deprivation but moderated the expression of BnaSultr1.1 in S-deprived plants without affecting the activity of root sulfate transporters. The effects of Si on the amount of S taken-up and on S transporter gene expression were also evaluated after 72 h of S resupply. In S-deprived plants, S re-feeding led to a strong decrease in the expression of both S transporter genes as expected, except in Si-treated plants where BnaSultr1.1 expression was maintained over time. This result is discussed in relation to the similar amount of S accumulated regardless of the Si treatment.

Co-fertilization of Sulfur and Struvite-Phosphorus in a Slow-Release Fertilizer Improves Soybean Cultivation.

In face of the alarming world population growth predictions and its threat to food security, the development of sustainable fertilizer alternatives is urgent. Moreover, fertilizer performance should be assessed not only in terms of yield but also in root system development, as it impacts soil fertility and crop productivity. Fertilizers containing a polysulfide matrix (PS) with dispersed struvite (St) were studied for S and P nutrition due to their controlled-release behavior. Soybean cultivation in a closed system with St/PS composites provided superior biomass compared to a reference of triple superphosphate (TSP) with ammonium sulfate (AS), with up to 3 and 10 times higher mass of shoots and roots, respectively. Root system architectural changes may explain these results, with a higher proliferation of second order lateral roots in response to struvite ongoing P delivery. The total root length was between 1,942 and 4,291 cm for plants under St/PS composites and only 982 cm with TSP/AS. While phosphorus uptake efficiency was similar in all fertilized treatments (11–14%), St/PS achieved a 22% sulfur uptake efficiency against only 8% from TSP/AS. Overall, the composites showed great potential as efficient slow-release fertilizers for enhanced soybean productivity.

Set of miRNAs Involved in Sulfur Uptake and the Assimilation Pathway of Indian Mustard (B. juncea) in Response to Sulfur Treatments.

MicroRNAs (miRNAs) play an important role in the regulation of gene expression. They play a regulatory role in various nutrient assimilatory pathways of plants; however, their role in the regulation of sulfur uptake and assimilatory pathways in mustard cultivars under high/low sulfur conditions is not elucidated. Sulfur is essential for plant growth and development, and its deficiency can cause a decline in oil seed content and thus lower the economic yield in Brassica juncea. In this study, different miRNAs involved in the regulation of sulfur uptake and assimilation pathways in B. juncea were identified using a psRNA target analyzer and miRanda database tools. The predicted miRNAs that belong to 10 highly conserved families were validated using stem-loop RT-PCR. The B. juncea cultivars Pusa Jaikisan, Pusa Bold, and Varuna were kept in sulfur-excessive (high) and -deficient (insufficient) conditions, and expression studies of miRNAs and their target mRNAs were carried out using qRT-PCR. The correlation between the expression pattern of miRNAs and their target genes showed their potential role in sulfur uptake and assimilation. Analysis with 5′ RACE revealed the authentic target of miRNAs. The influence of S treatments on metabolites and sulfur content was also studied using GC-MS and a CHNS analyzer. Our study showed the potential role of miRNAs in the regulation of sulfur uptake and assimilation and put forward the implications of these molecules to enhance the sulfur content of B. juncea.

Sulfur Compounds in Regulation of Stomatal Movement.

Sulfur, widely present in the soil and atmosphere, is one of the essential elements for plants. Sulfate is a dominant form of sulfur in soils taken up by plant roots. In addition to the assimilation into sulfur compounds essential for plant growth and development, it has been reported recently that sulfate as well as other sulfur containing compounds can also induce stomatal movement. Here, we first summarized the uptake and transport of sulfate and atmospheric sulfur, including H2O and SO2, and then, focused on the effects of inorganic and organic sulfur on stomatal movement. We concluded all the transporters for different sulfur compounds, and compared the expression level of those transporters in guard cells and mesophyll cells. The relationship between abscisic acid and sulfur compounds in regulation of stomatal movement were also discussed.

Organic and inorganic sulfur and nitrogen uptake by co-existing grassland plant species competing with soil microorganisms

Cysteine (Cys) and methionine (Met) are unique amino acids that contain not only nitrogen (N) but also sulfur (S); thus, they are a source of S for plants under low-soil-SO42- conditions. However, whether low-molecular-weight organic N and S can be utilised by plants or contribute to plant growth remains unknown. Therefore, this study aimed to examine the uptake of organic and inorganic N and S by plants and the role of microbial decomposition under monocropping and intercropping based on 13C, 15N, 14C, and 35S quad labelling. As indicated by the 13C/14C uptake, clover, millet, and ryegrass utilised 0.24–1.68% of the added Cys and Met within 6 h and encountered considerable competition from soil microorganisms. The added Met and Cys were rapidly utilised by microorganisms, and part of the N was subsequently released as inorganic N, which was taken up by plants (15N-Cys: 9.3–15.2%; 15N-Met: 5.9–13.4%) within 6 h. Six hours after addition, 57.8–78.5% of the 35S-Met and 26.2–56.0% of the 35S-Cys were retained in the microbial biomass, while more 35S-Cys was mineralised to SO42−. Plants took up 5.5–12.4% of 35S-Cys and only 3.4–6.0% of 35S-Met, and 35S uptake was dominated by inorganic S after the mineralisation of Cys and Met. N uptake from Cys and Met accounted for less than 1% of the total N uptake from the soil, while S uptake from Cys and Met accounted for 9.3–27.0% and 2.8–11.8% of the total S uptake from the soil, respectively. Additionally, Cys was more rapidly mineralised to SO42− by soil microbes than Met; the produced SO42− was further utilised by plant roots. The contributions of Cys and Met to the total N and S uptake were the highest in millet monocropping while intercropping altered the relative contributions of organic and inorganic N and S. Overall, soil soluble Cys and Met played a limited role in plant N uptake but were an important source of plant S uptake.

Screening of Groundnut Genotypes for Sulphur Utilization Potential

A microplot experiment was conducted on a medium black soil for screening of groundnut genotypes for improved S utilization. From this experiment four different S sources viz., Gypsum, SSP, FeSO4, and ZnSO4, were applied at four levels (S @ 0, 20, 30, and 40 kg ha-1). The results revealed that the addition of 40 kg S ha-1 as FeSO4 substantially increased the dry matter production and sulphur uptake irrespective of groundnut genotypes. Sulphur application in the form of SSP enhanced the root length and number of pods per plant. Groundnut genotypes CO7, VRI 8, and TMV 14 were categorized as efficient S utilizers, while BSR 2 and ALR 3 were recorded to be inefficient S utilizers.

Genomewide transcriptional response of Escherichia coli O157:H7 to norepinephrine

BackgroundChemical signaling between a mammalian host and intestinal microbes is health and maintenance of ‘healthy’ intestinal microbiota. Escherichia coli O157:H7 can hijack host- and microbiota-produced chemical signals for survival in a harsh and nutritionally competitive gastrointestinal environment and for intestinal colonization. Norepinephrine (NE) produced by sympathetic neurons of the enteric nervous system has been shown in vitro to induce expression of genes controlling E. coli O157:H7 swimming motility, acid resistance, and adherence to epithelial cells. A previous study used a microarray approach to identify differentially expressed genes in E. coli O157:H7 strain EDL933 in response to NE. To elucidate a comprehensive transcriptional response to NE, we performed RNA-Seq on rRNA-depleted RNA of E. coli O157:H7 strain NADC 6564, an isolate of a foodborne E. coli O157:H7 strain 86–24. The reads generated by RNA-Seq were mapped to NADC 6564 genome using HiSat2. The mapped reads were quantified by htseq-count against the genome of strain NADC 6564. The differentially expressed genes were identified by analyzing quantified reads by DESeq2.ResultsOf the 585 differentially expressed genes (≥ 2.0-fold; p < 0.05), many encoded pathways promoting ability of E. coli O157:H7 strain NADC 6564 to colonize intestines of carrier animals and to produce disease in an incidental human host through increased adherence to epithelial cells and production of Shiga toxins. In addition, NE exposure also induced the expression of genes encoding pathways conferring prolonged survival at extreme acidity, controlling influx/efflux of specific nutrients/metabolites, and modulating tolerance to various stressors. A correlation was also observed between the EvgS/EvgA signal transduction system and the ability of bacterial cells to survive exposure to high acidity for several hours. Many genes involved in nitrogen, sulfur, and amino acid uptake were upregulated while genes linked to iron (Fe3+) acquisition and transport were downregulated.ConclusionThe availability of physiological levels of NE in gastrointestinal tract could serve as an important cue for E. coli O157:H7 to engineer its virulence, stress, and metabolic pathways for colonization in reservoir animals, such as cattle, causing illness in humans, and surviving outside of a host.

Yield, nutrient uptake, and economic return of faba bean (Vicia faba L.) in calcareous soil as affected by compost types

Compost application is a promising approach to improve soil fertility and the sustainability of plant production, but different types of compost may vary in their efficiency. A field experiment was carried out to evaluate the effect of traditional compost, vermicompost, and material composted with additional effective microorganisms (EM) on faba bean yield and related properties. The compost treatments were applied at three nitrogen levels (18, 27, and 36 kg ha −1 ) and compared to mineral fertilizer alone or in combination with compost in a two-factor randomized complete block design with four replicates. The economic effects of the different composts were assessed using partial budget analysis. All three composts resulted in significantly higher grain and biomass yields, as well as nutrient uptake into grain compared to mineral fertilizer. This was reflected in a higher number of nodules and higher residual soil nitrogen in the compost treatments. However, EM and vermicompost were most efficient, with a yield of approximately 3.6 and 3.45 t ha −1 , respectively, compared to traditional compost with a yield of 3.1 t. Similar results were found for other investigated properties. The economic analysis revealed that EM compost application at medium and high nitrogen rates was the most profitable among the treatments, with marginal rates of return varying between approximately 790 and 2800%. • EM compost and vermicompost addition resulted in significantly higher grain yield, biomass yield, number of nodules, and residual nitrogen than traditional compost and mineral fertilizer. • Nitrogen, phosphorus, and sulphur uptake into grain and straw were significantly higher on EM and vermicompost treated plots. • EM compost application based on medium and high nitrogen rates and EM compost with mineral fertilizer resulted in the best economic performance among the treatments.

Exploring the Role of Mycorrhizal and Rhizobium Inoculation with Organic and Inorganic Fertilizers on the Nutrient Uptake and Growth of Acacia mangium Saplings in Acidic Soil

Strong and healthy saplings are a prerequisite to establish a successful forest. Therefore, an attempt has been made to develop the best package for nutrient supplementation to raise healthy Acacia mangium saplings, especially in acidic soil. The seeds were sown in pots, receiving different combinations of Arbuscularmycorrhizal (AM), Rhizobium inoculation with application of lime, and mustard oil cake (MOC). The highest spore count and infection percentage (3220 kg−1 soil and 69) were recorded in the AM + MOC + R treated pot, whereas the lowest (2553 kg−1 soil and 37) were recorded in the AM + L treated pot. Nitrogen concentration and uptake in the sapling were higher in the Rhizobium-inoculated treatments than the uninoculated ones. The sulfur concentration and uptake were higher in the MOC-supplemented treatment. Similarly, the P, K, Ca, and Mg concentrations and uptakes were higher in the limed treatments than the unlimed ones. The micronutrient concentration and uptake were higher in the unlimed treatments compared to the lime practice. The concentration of N in Rhizobium-treated pots, P and K in lime-treated pots, and S in MOC-treated pots were increased, whereas the soil pH decreased in all treatments except in the integrated package (AM + MOC + R + L) after 120 days. The Ca and Mg were reduced in all treatments, whereas micronutrients were reduced in all packages except the control. Under different nutrient management practices, plant height and stem girth continuously increased by 9.5 to 12 cm and 3 to 4 times, respectively. The production of robust saplings required integrated application of lime, MOC, AM, and Rhizobium in an acid soil that facilitated better root growth with availability of adequate nutrients for saplings.

Sulfur transformations during two-stage anaerobic digestion and intermediate thermal hydrolysis

The formation of hydrogen sulfide (H2S) during anaerobic digestion (AD) imposes constraints on the valorisation of biogas. So far, inorganic sulfur compounds -mainly sulfate - have been considered as the main contributors to H2S formation, while the contribution of organic sulfur compounds is mostly neglected. This study investigates the fate of organic and inorganic sulfur compounds during two-stage anaerobic digestion with intermediate thermal hydrolysis for treatment of primary and secondary sludge in a WWTP treating domestic wastewater. The results of a seven-week monitoring campaign showed an overall decrease of organic sulfur compounds in both stages of anaerobic digestion. Further fractionation of organic sulfur revealed a high conversion of the particulate organic fraction during the first digestion stage and of the soluble organic fraction during the second digestion stage. The decrease of soluble organic sulfur during the second digestion stage was attributed to the solubilisation and hydrolysis of sulfur-containing organic compounds during thermal hydrolysis. In both digestion stages, more organic sulfur was taken up than particulate inorganic sulfur (metal sulfide) was produced, indicating the formation of other reduced sulfur forms (e.g. H2S). Further batch experiments confirmed the role of organic sulfur uptake in the formation of H2S during anaerobic digestion as sulfate reduction only partly explained the total sulfide formed (H2S in biogas and precipitated FeS). Overall, the conversion of organic sulfur was demonstrated to play a major role in H2S formation (and thus the biogas quality), especially in case of thermal hydrolysis pretreatment.

Light-Enhanced Oxidative Adsorption Desulfurization of Diesel Fuel over TiO2–ZrO2 Mixed Oxides

This study explored a new method for the adsorptive desulfurization of liquid hydrocarbon fuels called “light-enhanced oxidative adsorption desulfurization (LEOADS)”, which combines the photo-oxidation of aromatic sulfur compounds with the adsorption of oxidized-sulfur compounds over an adsorbent. The LEOADS of dibenzothiophene in real diesel fuel (DBT/diesel) was conducted in a batch system under UV–vis irradiation at ambient conditions using air as an oxidant. The desulfurization performance of DBT decreased in the order of TiO2–ZrO2 ≫ TiO2-CeO2 > TiO2 ≈ ZrO2. Introducing simultaneous light irradiation together with an adsorption process using TiO2–ZrO2 can dramatically improve the sulfur uptake by 9-fold (5.2 mg-S/g-A) compared to one-step adsorptive desulfurization (0.6 mg-S/g-A) and by 1.4-fold compared to two-step photo-oxidative desulfurization (3.8 mg-S/g-A). Light and TiO2–ZrO2 play important roles in the LEOADS: Light enhanced peroxide generation and the TiO2–ZrO2 promoted the oxidation of DBT to DBTO2 with the in situ generated peroxide. X-ray diffraction, UV–vis spectroscopy, N2-adsorption desorption, and scanning electron microscopy techniques were used for the characterization of the materials.

Aspects of the Neurospora crassa Sulfur Starvation Response Are Revealed by Transcriptional Profiling and DNA Affinity Purification Sequencing.

ABSTRACTAccurate nutrient sensing is important for rapid fungal growth and exploitation of available resources. Sulfur is an important nutrient source found in a number of biological macromolecules, including proteins and lipids. The model filamentous fungus Neurospora crassa is capable of utilizing sulfur found in a variety of sources from amino acids to sulfate. During sulfur starvation, the transcription factor CYS-3 is responsible for upregulation of genes involved in sulfur uptake and assimilation. Using a combination of RNA sequencing and DNA affinity purification sequencing, we performed a global survey of the N. crassa sulfur starvation response and the role of CYS-3 in regulating sulfur-responsive genes. The CYS-3 transcription factor bound the promoters and regulated genes involved in sulfur metabolism. Additionally, CYS-3 directly activated the expression of a number of uncharacterized transporter genes, suggesting that regulation of sulfur import is an important aspect of regulation by CYS-3. CYS-3 also directly regulated the expression of genes involved in mitochondrial electron transfer. During sulfur starvation, genes involved in nitrogen metabolism, such as amino acid and nucleic acid metabolic pathways, along with genes encoding proteases and nucleases that are necessary for scavenging nitrogen, were activated. Sulfur starvation also caused changes in the expression of genes involved in carbohydrate metabolism, such as those encoding glycosyl hydrolases. Thus, our data suggest a connection between sulfur metabolism and other aspects of cellular metabolism.IMPORTANCE Identification of nutrients present in the environment is a challenge common to all organisms. Sulfur is an important nutrient source found in proteins, lipids, and electron carriers that are required for the survival of filamentous fungi such as Neurospora crassa. Here, we transcriptionally profiled the response of N. crassa to characterize the global response to sulfur starvation. We also used DNA affinity purification sequencing to identify the direct downstream targets of the transcription factor responsible for regulating genes involved in sulfur uptake and assimilation. Along with genes involved in sulfur metabolism, this transcription factor regulated a number of uncharacterized transporter genes and genes involved in mitochondrial electron transfer. Our data also suggest a connection between sulfur, nitrogen, and carbon metabolism, indicating that the regulation of a number of metabolic pathways is intertwined.

Need for Determining the Effects of Sulphur Fertilization on the Amounts of Organic Sulphur Compounds in Plant Foods

A large number of field trials are being conducted in India and across the globe on the yield response and uptake of sulphur (S) in a number of crops and most results show a good yield response. However, none of the studies bring out the effect of S fertilization on S containing amino acids viz. cysteine, methionine and vitamin like Thiamine, which are essential for human life and are to be obtained only from plant foods. It is due to lack of awareness and also poor infrastructures in terms of biochemical analysis of the agricultural produce in most of the developing countries including India. Therefore, there is an urgent need to establish food quality analysis laboratories in the leading institutes of the country for initiating analysis of plant foods for S-containing organic compounds

Micrografting Provides Evidence for Systemic Regulation of Sulfur Metabolism between Shoot and Root.

The uptake of sulfate by roots and its reductive assimilation mainly in the leaves are not only essential for plant growth and development but also for defense responses against biotic and abiotic stresses. The latter functions result in stimulus-induced fluctuations of sulfur demand at the cellular level. However, the maintenance and acclimation of sulfur homeostasis at local and systemic levels is not fully understood. Previous research mostly focused on signaling in response to external sulfate supply to roots. Here we apply micrografting of Arabidopsis wildtype knock-down sir1-1 mutant plants that suffer from an internally lowered reductive sulfur assimilation and a concomitant slow growth phenotype. Homografts of wildtype and sir1-1 confirm the hallmarks of non-grafted sir1-1 mutants, displaying substantial induction of sulfate transporter genes in roots and sulfate accumulation in shoots. Heterografts of wildtype scions and sir1-1 rootstocks and vice versa, respectively, demonstrate a dominant role of the shoot over the root with respect to sulfur-related gene expression, sulfate accumulation and organic sulfur metabolites, including the regulatory compound O-acetylserine. The results provide evidence for demand-driven control of the shoot over the sulfate uptake system of roots under sulfur-sufficient conditions, allowing sulfur uptake and transport to the shoot for dynamic responses.

Synergistic decomposition of H2S into H2 by Ni3S2 over ZrO2 support via a sulfur looping scheme with CO2 enabled carrier regeneration

Commercially viable H2 production from H2S demands a well-designed and efficient technology concept with superior H2 yield. We propose a novel sulfur looping scheme that involves carrier sulfidation and CO2 enabled carrier regeneration to simultaneously utilize H2S and CO2, the two common industrial waste gases, for valuable H2 production. Using Ni3S2 as the active component, a high-performance sulfur carrier design is developed, where the selection of support is key. ZrO2 and MgAl2O4 supports were tested and both substantially improve the recyclability over cycles by imparting structural stability to Ni3S2. ZrO2 dramatically enhances the carrier performance, exhibiting a maximum increase of ~ 100% in sulfur uptake during the redox cycles compared to MgAl2O4. Furthermore, in fixed bed experiments at a high GHSV of 5000 hr-1, ZrO2 supported carrier maintained its superior performance over MgAl2O4 with a ~ 9.5% higher total H2S consumption. Density functional theory calculations were performed to unveil the role of supports. ZrO2 is identified as a support with bifunctional characteristics that not only improves textural properties of the carrier, but also catalytically decomposes H2S and induces a synergistic dynamic with Ni3S2. On the other hand, MgAl2O4 acts only as a conventional inert support for morphology modifications with negligible interaction with H2S. This work demonstrates a novel strategy for H2S and CO2 utilization and provides new insights into effective support selection aiding the design of a robust and efficient sulfur carrier.

Response of Groundnut (Arachis hypogaea L.) to Different Levels and Time of Phosphogypsum Nutrition

Background: Groundnut is one of the most important oilseed crops of India. Improving productivity of groundnut to meet the domestic vegetable oil demand through balanced fertilization is the prime challenge lying before the agronomists in the country. With the aim of evaluating phosphogypsum as a source of sulphur nutrition in groundnut, a field experiment entitled “Response of groundnut (Arachis hypogaea L.) to different levels and time of phosphogypsum nutrition” was conducted at Agronomy field unit, University of Agricultural Sciences Bangalore, during kharif-2019. Methods: Experiment was laid out in randomised complete block design (RCBD) with eleven treatments, of which eight have different combinations of phosphogypsum applied as basal and in split (30 DAS) and one with gypsum as basal alone. Whereas, the remaining two treatments, without any additional source of sulphur are included for comparison. Result: Among eleven treatments, application of phosphogypsum @ 125 kg S eq ha-1 in split recorded highest yield attributes, pod yield (2063 kg ha-1), kernel yield (1418 kg ha-1) and sulphur uptake (11.33 kg ha-1). Which were on par with 100 kg S eq ha-1 in split (2014, 1380 and 10.39 kg ha-1, respectively). All other treatments recorded lower values with lowest in treatments without any additional sulphur source.

Evaluation of the Sulphur-Supplying Ability of Soils to Support Plant Growth and Assessment of Relative Crop Response to Sulphur Application through Neubauer Technique

Sulphur plays a vital role in the nutrition of oilseeds and pulses. Along with nitrogen and phosphorus, it plays an important role in the formation of proteins and is involved in the metabolic and enzymatic processes of all living cells. Several biological techniques have been studied in order to assess sulphur deficiency or sufficiency in different groups of sulphur fertilizer for achieving the optimum yield of crops of which Neubauer technique is generally considered as one such tool that can be used for piloting the sulphur supplying capacity of the soils to supplement its requirement for the establishment of the plant. Surface (0-15 cm) soil samples from typical rice and pulse growing fields spread over the dominant soil groups of West Bengal which belong under 16 identified soil series were collected for this study. In order to assess sulphur availability in soils Neubauer technique was employed. Under sulphur treatment, the lowest dry matter yield and uptake by shoot was recorded in Bankul soil. Among the soils, the lowest root dry matter yield at control treatment was recorded in patapahari soil and the highest was in Hijalgara soil. A similar trend was also observed in case of S uptake by the shoot. While highest dry matter yield and maximum sulphur uptake by shoot was registered in Sukhnibasa and kusmi soil respectively. Likewise for N, P and K elements, the Neubauer technique may be used as one of the biological techniques for evaluating S response to crops as well as S supplying capacity of the soil to support plant growth.