Sulfur Uptake Research Articles

System Intensification in Ridges and Furrow Planting to Enhance Nutrient Uptake Efficiency in Soybean

Through the study we aim to explore agronomic intervention to provide nutritional security to growing population, with limited resources and changing climatic conditions. The objective of the study is to investigate the impact of system intensification on nutrient content and nutrient uptake in soybean varieties within ridge and furrow planting system. The experiment was conducted during Kharif 2019 at Pantnagar, India. It was designed in a split-plot layout with eight treatments, replicated thrice. The main plot treatments included two soybean varieties: PS-1092 and SL-958. Four system intensification treatments were within the sub-plots, (plant-to-plant spacing -5 cm, 10 cm, 15 cm, and 20 cm). Nitrogen, Phosphorus, Potassium and Sulfur content in seed was significantly highest at spacing 10 cm as compared to other spacing treatments (P value=.05). Nitrogen, Phosphorus Potassium and Sulfur uptake for both seed and stover was the maximum at plant to plant spacing of 10 cm which was significantly higher than other plant to plant spacing treatments at 5 % level of significance. Intense plant to plant spacing of 10 cm resulted into the significantly higher partial factor productivity (PFP) of nutrients at P=.05. Although nutrient content, nutrient uptake and PFP in soybean is higher at plant to plant spacing of 10 cm, nutrient harvest index is better achieved at wider spacing of 15 to 20 cm. Under no fertilizer limitation, system intensification can be useful to enhance nutrient content of seeds but in cases of limited fertilizer availability wider spacing is more beneficial to achieve higher nutrient use efficiency. Further investigations are needed to fine-tune these practices across diverse geographic regions and soil types. GHG emissions from soybean grown in varying planting geometry needs to be studied.

Response of Fertility Levels and Liquid Biofertilizers on Soil Chemical Properties and Nutrient Uptake under Wheat (Triticum aestivum L.) Crop

A field experiment was conducted during rabi 2019-20 at Instructional Farm of Agronomy, Rajasthan College of Agriculture, Udaipur to examine the effect of fertility levels and liquid biofertilizers on soil chemical properties and nutrient uptake by wheat. The treatments comprised of four levels of fertility (i.e. control, 75, 100 and 125% RDF) and four levels of liquid biofertilizers (i.e. no inoculation, Azotobacter, PSB and Azotobacter + PSB). Experiment was laid out in Factorial Randomized Block Design with three replication taking wheat var Raj 4238 as test crop. The recommended dose of fertilizer (RDF) was 100:60:40 kg ha-1 of N:P2O5:K2O. The results revealed that significant increase in available primary nutrient (nitrogen, phosphorus and potassium) in post harvest soil of wheat and also significantly increase in nitrogen, phosphorus, potassium, sulfur and micronutrients (Cu, Zn, Fe and Mn) uptake by wheat with increasing levels of fertility and liquid biofertilizers up to the 100% RDF and Azotobacter + PSB respectively.

Available sulfur release and sulfur uptake as influenced by animal manures and wood ash under maize-grown soils

Available sulfur release and sulfur uptake as influenced by animal manures and wood ash under maize-grown soils

Effect of Potassium and Sulphur on Nutrient Uptake and Economics of Coriander (Coriandrum sativum L.)

A field experiment was conducted during rabi 2021-22 at Agronomy Instructional Farm, Sardarkrushinagar Dantiwada Agricultural University, Sardarkrushinagar, Gujarat on loamy sand soil to study the response of coriander (Coriandrum sativum L.) to potassium and sulphur. The experiment was laid out in factorial randomized block design (FRBD) consisted three level each of potassium (0, 20 and 40 kg/ha) and sulphur (0, 15 and 30 kg/ha) and replicated four times. Application of 40 kg K2O/ha gave significantly higher potassium content and uptake in seed and straw. However, different levels of potassium on sulphur content in seed and straw of coriander was not significant. The maximum sulphur content and uptake in seed and straw was recorded with application of 30 kg S/ha but sulphur application do not influence on potassium content in seed and straw. Application of 40 kg K2O /ha and to 30 kg S/ha gave significantly higher gross and net realizations as well as BCR. While, application of 20 kg K2O /ha and 15 kg S/ha resulted in the higher ICBR.

Effect of Inorganic Fertilizers in Combination with Biofertilizers on Nutrient Content and Uptake of Kharif Maize

A field experiment entitled “Effect of inorganic fertilizers in combination with biofertilizers on nutrient content and uptake of kharif maize” was conducted at Agriculture College Farm, Bapatla, during both kharif 2020 and 2021. The experiment was laid out in randomized block design (RBD) with seven treatments and replicated thrice. The treatments consisted of T1- Control; T2- 100% RDF; T3- 125% RDF; T4 – 100% RDF + VAM; T5- 100% RDF +VAM + Azospirillum + PSB; T6- 75 % RDF + VAM; T7- 75 % RDF + VAM + Azospirillum + PSB. During kharif in two years of study significantly higher nitrogen content and uptake was recorded with 125 % RDF (T3) it was on par with 100% RDF + VAM + Azospirillum + PSB (T5) and 100% RDF + VAM (T4). The maximum nitrogen content and uptake was significantly influenced due to various level of inorganic fertilizers. Higher phosphorus, potassium and sulphur (non-significant) content and uptake were recorded in the treatment T5 that received 100% RDF +VAM + Azospirillum + PSB and it was on par with treatment which received 75 % RDF + VAM + Azospirillum + PSB (T7), 125 % RDF (T3) and 100% RDF + VAM (T4) at knee high, tasseling and harvest stage of maize. The results revealed that application of biofertilizers along with inorganic fertilizers significantly increased plant nutrient content and uptake of maize crop.

Changes in sulfur in soybean rhizosphere soil and the response of microbial flora in a continuous cropping system mediated by Funneliformis mosseae.

Soybean is an S-loving crop, and continuous cropping might cause soil sulfur shortage. The primary objectives of this study are to determine whether Funneliformis mosseae (F. mosseae) can enhance the content of available S in S-deficient soil and thereby improve the sulfur utilization rate in soybean. The experiment used Heinong 48 (HN48), a soybean variety with a vast planting area in Heilongjiang Province, and F. mosseae was inoculated in the soil of soybean that had been continuously cropped for 0 and 3 years. The results of the barium sulfur turbidimetric assay show that the sulfur content in the soil and soybean was reduced by continuous cropping and increased by inoculation with F. mosseae; the results of the macro-genome sequencing technology, show that the diversity and abundance of bacteria in the soil was decreased by continuous cropping and increased by inoculation with F. mosseae. The sulfur-oxidizing bacteria (SOB) activity and sulfur-related gene expression levels were lower in the continuous crop group compared to the control group and higher in the F.mosseae-inoculated group compared to the control group. Continuous cropping reduced the sulfur content and ratio of soybean rhizosphere soil, affecting soil flora activity and thus soybean growth; F. mosseae inoculation increased the sulfur content of soybean root-perimeter soil and plants, increased the diversity and abundance of rhizosphere soil microorganisms, increased the expression of genes for sulfur transport systems, sulfur metabolism, and other metabolic functions related to elemental sulfur, and increased the species abundance and metabolic vigor of most SOB. In summary, continuous cropping inhibits soil sulfur uptake and utilization in soybean while the inoculation with F. mosseae can significantly improve this situation. This study offers a theoretical research foundation for using AMF as a bio-fungal agent to enhance soil sulfur use. It also supports the decrease of chemical fertilizers, their substitution, and the protection of native soil.

ATP sulfurylase atypical leucine zipper interacts with Cys3 and calcineurin A in the regulation of sulfur amino acid biosynthesis in Cryptococcus neoformans

Fungal pathogens are a major cause of death, especially among immunocompromised patients. Therapies against invasive fungal infections are restricted to a few antifungals; therefore, novel therapies are necessary. Nutritional signaling and regulation are important for pathogen establishment in the host. In Cryptococcus neoformans, the causal agent of fungal meningitis, amino acid uptake and biosynthesis are major aspects of nutritional adaptation. Disruptions in these pathways lead to virulence attenuation in an animal model of infection, especially for sulfur uptake and sulfur amino acid biosynthesis. Deletion of Cys3, the main transcription factor that controls these pathways, is the most deleterious gene knockout in vitro and in vivo, making it an important target for further application. Previously, we demonstrated that Cys3 is part of a protein complex, including calcineurin, which is necessary to maintain high Cys3 protein levels during sulfur uptake and sulfur amino acid biosynthesis. In the current study, other aspects of Cys3 regulation are explored. Two lines of evidence suggest that C. neoformans Cys3 does not interact with the F-box WD40 protein annotated as Met30, indicating another protein mediates Cys3 ubiquitin degradation. However, we found another level of Cys3 regulation, which involves protein interactions between Cys3 and ATP sulfurylase (MET3 gene). We show that an atypical leucine zipper at the N-terminus of ATP sulfurylase is essential for physical interaction with Cys3 and calcineurin. Our data suggests that Cys3 and ATP sulfurylase interact to regulate Cys3 transcriptional activity. This work evidences the complexity involved in the regulation of a transcription factor essential for the sulfur metabolism, which is a biological process important to nutritional adaptation, oxidative stress response, nucleic acid stability, and methylation. This information may be useful in designing novel therapies against fungal infections.

Plant and fungal gene expression coupled with stable isotope labeling provide novel information on sulfur uptake and metabolism in orchid mycorrhizal protocorms.

Orchid mycorrhiza (OM) represents an unusual symbiosis between plants and fungi because in all orchid species carbon is provided to the host plant by the mycorrhizal fungus at least during the early stages of orchid development, named a protocorm. In addition to carbon, orchid mycorrhizal fungi provide the host plant with essential nutrients such as phosphorus and nitrogen. In mycorrhizal protocorms, nutrients transfer occurs in plant cells colonized by the intracellular fungal coils, or pelotons. Whereas the transfer of these vital nutrients to the orchid protocorm in the OM symbiosis has been already investigated, there is currently no information on the transfer of sulfur (S). Here, we used ultra-high spatial resolution secondary ion mass spectrometry (SIMS) as well as targeted gene expression studies and laser microdissection to decipher S metabolism and transfer in the model system formed by the Mediterranean orchid Serapias vomeracea and the mycorrhizal fungus Tulasnella calospora. We revealed that the fungal partner is actively involved in S supply to the host plant, and expression of plant and fungal genes involved in S uptake and metabolism, both in the symbiotic and asymbiotic partners, suggest that S transfer most likely occurs as reduced organic forms. Thus, this study provides originalinformation about the regulation of S metabolism in OM protocorms, adding a piece of the puzzle on the nutritional framework in OM symbiosis.

Influence of container, potting media and nutrients on production and post-production consumer acceptance of potted marigold (Tagetes patula L.)

Production of potted plants is influenced by factors viz., type of container, potting medium, nutrient dose. A study was conducted to standardize these factors for potted French marigold var. Arka Pari. The treatments comprised of two type of containers (plastic and coir), three potting media [red soil + FYM + sand (1:1:1 v/v), Arka fermented cocopeat (AFC), AFC + vermicompost (1:1 v/v)] and four nutrition concentrations (160:30:180 ppm N:P: K, 128:24:144 ppm N:P: K, 96:18:108 ppm N:P:K and 3% Jeevamrutha) laid out in factorial completely randomized design replicated thrice. Plants grown in potting media combination of Arka fermented cocopeat (AFC) + vermicompost (1:1 v/v) along with weekly application of nutrient solution (128:24:144 ppm NPK) produced maximum number of flowers plant-1 (147.61) and registered highest uptake of nitrogen (2.87 g plant-1), phosphorus (0.53 g plant-1), potassium (3.24 g plant-1), magnesium (0.85 g plant-1) and sulphur (0.21 g plant-1). Based on the attributes of the potted plants, this treatment combination also registered the highest score (81.2 on a scale of 100), willingness of the consumers to purchase (4.5 on a scale of 5), overall acceptability (2.7 on a scale of 3) and the benefit cost ratio of 1.18.

Arbuscular mycorrhizal fungi enhance phosphate uptake and alter bacterial communities in maize rhizosphere soil.

Arbuscular mycorrhizal fungi (AMF) can symbiose with many plants and improve nutrient uptake for their host plant. Rhizosphere microorganisms have been pointed to play important roles in helping AMF to mobilize soil insoluble nutrients, especially phosphorus. Whether the change in phosphate transport under AMF colonization will affect rhizosphere microorganisms is still unknown. Here, we evaluated the links of interactions among AMF and the rhizosphere bacterial community of maize (Zea mays L.) by using a maize mycorrhizal defective mutant. Loss of mycorrhizal symbiosis function reduced the phosphorus concentration, biomass, and shoot length of maize colonized by AMF. Using 16S rRNA gene amplicon high-throughput sequencing, we found that the mutant material shifted the bacterial community in the rhizosphere under AMF colonization. Further functional prediction based on amplicon sequencing indicated that rhizosphere bacteria involved in sulfur reduction were recruited by the AMF colonized mutant but reduced in the AMF- colonized wild type. These bacteria harbored much abundance of sulfur metabolism-related genes and negatively correlated with biomass and phosphorus concentrations of maize. Collectively, this study shows that AMF symbiosis recruited rhizosphere bacterial communities to improve soil phosphate mobilization, which may also play a potential role in regulating sulfur uptake. This study provides a theoretical basis for improving crop adaptation to nutrient deficiency through soil microbial management practices.

Influence of Long-Term Organic Fertilization on Changes in the Content of Various Forms of Sulfur in the Soil under Maize Monoculture

Sulfur nutrition is a crucial part of proper crop growth. In this study, we investigated the influence of organic fertilizers in a long-term field experiment (23 years) with continuous maize monoculture. We focused on: (a) changes in the soil sulfur fraction pools, (b) the balance of total sulfur inputs and outputs, and (c) sulfur uptake by maize. The following treatments were selected: unfertilized control (Control), urea and ammonium nitrate (UAN), UAN and wheat straw (UAN + St), sewage sludge (SS), farmyard manure (FYM), and slurry (Slurry). Using sequential extraction, we determined water-soluble (SW—in water), adsorbed (Sads—in 0.032 mol L−1 NaH2PO4), and available (Sav = SW + Sads) sulfur content. Microwave-assisted digestion in an Aqua regia solution was used to measure the pseudo-total sulfur content (Spt). Organic-bound sulfur (Sorg) was calculated as a difference between Spt and Sav. We found that average biomass yields responded to a uniform 120 kg N ha−1 year−1 dose, rather than the dose of S in fertilizers, with an increase over the Control by 34–49%. The effect of an additional 33.5 kg N ha−1 year−1 on UAN + St treatment was not significant. Average sulfur uptake responded to increased yields (69-121% higher than Control), rather than the sulfur application, with the exception of SS, where the dose of sulfur was high enough to cause an additional uptake. In the topsoil, we discovered a significant decrease over time (from 1997 to 2019) in water-soluble (SW), adsorbed (Sads), available (Sav), and pseudo-total (Spt) fractions on all treatments to 29, 59, 37, and 82% of their initial values, respectively. For all treatments, the proportion of Sorg in Spt increased over time, which was caused by the decrease in mineral fractions (SW, Sads, Sav). The absolute content of Sorg decreased over time for all treatments except SS and FYM to about 85% of the initial value. Using the simple balancing method, we calculated that UAN + St, SS, FYM, and Slurry treatments annually lost 8.04, 66.1, 21.4, and 26.8 kg of S ha−1, respectively. This loss was attributed to the decrease in atmospheric depositions, as well as the release of sulfur from soil organic matter (for UAN + St and Slurry treatments) and a high proportion of easily mineralizable and inorganic sulfur from the SS treatment. Generally, the FYM fertilizer provided the highest potential for maintaining soil Spt status.

Role of Gypsum in Conserving Soil Moisture Macronutrients Uptake and Improving Wheat Yield in the Rainfed Area

Agricultural rainfed areas of Pakistan have been facing several issues in recent years, e.g., soil erosion, nutrient runoff, and soil dependency on rainfall for crop growth. Wheat is considered a major staple crop in Pakistan. The main concern in these regions is to conserve soil moisture as the crop depends on the moisture obtained by rainfall. Gypsum is considered one of the best moisture conservers, especially for rainfed areas. Hence, this study was initiated (1) to explore the effects of gypsum on soil moisture conservation and (2) to reveal the effects of gypsum on soil macronutrients, sulfur (S), calcium (Ca), nitrogen (N), phosphorus (P), and potassium (K) uptake, and, eventually, wheat yield. The study was conducted from July 2014 to April 2015 in the rainfed Pothohar region of Pakistan. The recommended mineral fertilizers (N120P80K60) along with the following gypsum treatments: T1 = gypsum @ 0 Mg ha−1 (0 kg plot−1), T2 = gypsum @ 1 Mg ha−1 (0.6 kg plot−1), T3 = gypsum @ 3 Mg ha−1 (1.8 kg plot−1), and T4 = gypsum @ 4 Mg ha−1 (2.4 kg plot−1) were applied. The Chakwal-50 wheat variety was sown, followed by gypsum application. The maximum moisture was recorded under the soil of treatment T4 each month. The soil moisture was conserved up to 21% (surface) and 23% (sub-surface) in January and February 2015, respectively, with a 4 Mg ha−1 gypsum application. The highest nitrogen (N, 448.68 kg ha−1), phosphorus (P, 50.6 kg ha−1), potassium (K, 185.7 Kg ha−1), sulfur (S, 9.75 kg ha−1), and calcium (Ca, 35.5 kg ha−1) uptake values were observed in treatment with a 3 Mg ha−1 gypsum application (p < 0.05). The mean values of the grain yield ranged between 1903.4 (T1) and 2387.2 (T4) kg ha−1. Compared with the yield under T1, the grain yields under treatment T2, T3, and T4 were increased by 11%, 24%, and 25%, respectively. The straw yield ranged between 2446 and 2767 kg ha−1. There was no noticeable impact of gypsum application rates on the straw yield of the wheat crop (p > 0.05). Overall, treatment T3 was found to be optimal for conserving soil moisture, a better nutrient uptake, and, ultimately, the wheat crop yield with less input cost.

Transcriptome Analysis of Cyclooctasulfur Oxidation and Reduction by the Neutrophilic Chemolithoautotrophic Sulfurovum indicum from Deep-Sea Hydrothermal Ecosystems.

Chemolithoautotrophic Campylobacterota are widespread and predominant in worldwide hydrothermal vents, and they are key players in the turnover of zero-valence sulfur. However, at present, the mechanism of cyclooctasulfur activation and catabolism in Campylobacterota bacteria is not clearly understood. Here, we investigated these processes in a hydrothermal vent isolate named Sulfurovum indicum ST-419. A transcriptome analysis revealed that multiple genes related to biofilm formation were highly expressed during both sulfur oxidation and reduction. Additionally, biofilms containing cells and EPS coated on sulfur particles were observed by SEM, suggesting that biofilm formation may be involved in S0 activation in Sulfurovum species. Meanwhile, several genes encoding the outer membrane proteins of OprD family were also highly expressed, and among them, gene IMZ28_RS00565 exhibited significantly high expressions by 2.53- and 7.63-fold changes under both conditions, respectively, which may play a role in sulfur uptake. However, other mechanisms could be involved in sulfur activation and uptake, as experiments with dialysis bags showed that direct contact between cells and sulfur particles was not mandatory for sulfur reduction activity, whereas cell growth via sulfur oxidation did require direct contact. This indirect reaction could be ascribed to the role of H2S and/or other thiol-containing compounds, such as cysteine and GSH, which could be produced in the culture medium during sulfur reduction. In the periplasm, the sulfur-oxidation-multienzyme complexes soxABXY1Z1 and soxCDY2Z2 are likely responsible for thiosulfate oxidation and S0 oxidation, respectively. In addition, among the four psr gene clusters encoding polysulfide reductases, only psrA3B3C3 was significantly upregulated under the sulfur reduction condition, implying its essential role in sulfur reduction. These results expand our understanding of the interactions of Campylobacterota with the zero-valence sulfur and their adaptability to deep-sea hydrothermal environments.

Thiourea fertilization effect on nutrient content and uptake of soybean cultivar

In the kharif season of 2020, an experimental trial was executed at Govind Ballabh Pant University of Agriculture and Technology which is situated in Pantnagar, India. The objective of this study was to evaluate how soybean's nutrient content and uptake responded to the application of thiourea through foliar means. The experiment was laid out in factorial randomized block design and comprised of two soybean cultivars viz., PS 1347 and SL 958 and five foliar sprays viz., control, water spray, thiourea spray @ 250 ppm, 500 ppm, and 750 ppm which were replicated four times. This study demonstrates the potential of foliar thiourea application to enhance the sulfur content and uptake of soybean cultivars in the kharif season. The findings of the study indicated that the N, P, and K content of soybean were not impacted by the type of variety used or by the foliar sprays administered. However, it was observed that the highest S content in both seeds (0.375%) and haulm (0.179%) was recorded when thiourea was applied through foliar means at a rate of 750 ppm. This result was statistically equivalent (0.368% in seed and 0.173% in haulm) to the outcome obtained from a 500 ppm foliar spray and both of these treatments were found to be more effective than the other foliar spray methods tested. Regarding the uptake of nutrients, it was observed that the highest levels of N, P, K, and S uptake by both seed and haulm as well as the total uptake, were recorded when a foliar spray containing 750 ppm of thiourea was used.

Characterization of sulfur-oxidizing bacteria isolated from mustard (Brassica juncea L.) rhizosphere having the capability of improving sulfur and nitrogen uptake.

The present investigation was carried out to isolate, screen and characterize potential sulfur-oxidizing bacteria (SOB) isolated from mustard field's soil. A total of 130 bacteria were isolated and after screening five maximum sulfate-producing isolates were optimized for culture conditions. The incubation time of 48 h was found optimum for all bacterial isolates and 30°C was the best temperature for the growth of SSD11, SSR1 and SSG8 whereas 35°C for SSF17. The pH8 was found best for all four isolates except SSF17 (6 pH). Media having glucose as a carbon source and ammonium sulphate as an N-source were producing maximum sulphate. The isolates SSF17, SSR1 and SSG8 were identified as Burkholderia cepacia (accession no. MT559819), Enterobacter cloacae (accession no. MT559820) and Klebsiella oxytoca (accession no. MT372097), respectively, on the basis of morphological, biochemical and molecular characterization. The isolates were also found to increase N and S uptake efficiently in both wheat and mustard crops. This study strongly concludes that SOB isolated from the mustard field can oxidize sulfur in vitro and in vivo conditions. The three best isolates come out of the study were identified as Burkholderia, Enterobacter and Klebsiella strains. Also, inoculation of SOB increased the uptake of S and N nutrient in mustard and wheat crops and thus may be proved as an important plant growth-promoting bacteria having the biofertilization capability. As we know, our soil is continuously deteriorating day by day due to excessive utilization and immoderate use of chemical fertilizers. The SOB could minimize the application of chemical fertilizers thus reducing environmental deterioration by improving soil health in sustainable agricultural practices.

Uptake of inorganic and organic phosphorus compounds by two marine sponges and their associated bacterial communities in aquaria.

Marine sponges are abundant filter-feeders in benthic ecosystems and many host copious microorganisms. Sponges and their symbionts have emerged as major players within marine biogeochemical cycles, facilitating uptake and release of carbon, nitrogen, and sulfur. Sponge holobionts' role in transforming dissolved carbon and nitrogen is well established; however, the same depth of understanding has not yet been extended to phosphorus. In this aquaria-based study, 32 P-labelled orthophosphate and ATP were used to determine that two sponges, Lendenfeldia chondrodes and Hymeniacidon heliophila, both take up ambient dissolved inorganic phosphate (DIP) and dissolved organic phosphorus (DOP). Subsequent genetic analyses and chemical extraction showed that sponge symbionts have the potential to synthesise polyphosphate (poly-P) and that this energy-rich form of stored phosphorus is present in both sponges. L. chondrodes, an oligotrophic sponge with a microbiome dominated by cyanobacteria, stores more phosphorus as poly-P (6%-8% of total phosphorus) than H. heliophila (0.55%), a eutrophic sponge with low cyanobacterial abundance. DIP/DOP uptake, as well as poly-P storage, may be driven by two factors: cyanobacterial abundance and nutrient availability. Considering their prevalence in phosphorus-limited ecosystems and their ability to pump large amounts of seawater, sponge holobionts are likely to be key players within benthic phosphorus cycles.

Cytokinin modulates the metabolic network of sulfur and glutathione.

The phytohormone cytokinin is implicated in a range of growth, developmental, and defense processes. A growing body of evidence supports a crosstalk between cytokinin and nutrient signaling pathways, such as nitrate availability. Cytokinin signaling regulates sulfur-responsive gene expression, but the underlying molecular mechanisms and their impact on sulfur-containing metabolites have not been systematically explored. Using a combination of genetic and pharmacological tools, we investigated the interplay between cytokinin signaling and sulfur homeostasis. Exogenous cytokinin triggered sulfur starvation-like gene expression accompanied by a decrease in sulfate and glutathione content. This process was uncoupled from the activity of the major transcriptional regulator of sulfate starvation signaling SULFUR LIMITATION 1 and an important glutathione-degrading enzyme, γ-glutamyl cyclotransferase 2;1, expression of which was robustly up-regulated by cytokinin. Conversely, glutathione accumulation was observed in mutants lacking the cytokinin receptor ARABIDOPSIS HISTIDINE KINASE 3 and in cytokinin-deficient plants. Cytokinin-deficient plants displayed improved root growth upon exposure to glutathione-depleting chemicals which was attributed to a higher capacity to maintain glutathione levels. These results shed new light on the interplay between cytokinin signaling and sulfur homeostasis. They position cytokinin as an important modulator of sulfur uptake, assimilation, and remobilization in plant defense against xenobiotics and root growth.

Sulfur uptake and distribution, grain yield, and quality of hybrid and inbred winter wheat (Triticum aestivum L.) varieties under early and late waterlogging

AbstractBackgroundWaterlogging at early and later growth stages could affect sulfur (S) uptake, distribution, yield, and quality of winter wheat. We hypothesized that the hybrid winter wheat variety (Hyvento), with a high degree of heterosis and genetic diversity, is likely to uptake and utilize S more efficiently and withstands waterlogging better than the inbred wheat variety (Kredo).AimsThe objective of the present study was to investigate the effect of 2‐week waterlogging at the end of tillering stage (Feekes Stage 6) and/or ear emergence stage (Feekes Stage 10.1) on grain yield, yield components, S‐uptake and its partitioning, and composition of grain storage proteins (glutenins and gliadins) of hybrid (Hyvento) and inbred (Kredo) winter wheat varieties.MethodsPlants were grown in large containers (120 L) in a semi‐controlled greenhouse and harvested three times immediately after each waterlogging treatment and at agronomic maturity. Grain yield, S concentration in different plant organs, total protein content, and patterns of gluten proteins (gliadin and glutenin) and their subunits (by sodium dodecyl sulfate–polyacrylamide gel electrophoresis) in grains were evaluated.ResultsGrain yield of the inbred variety was more negatively affected under early and late waterlogging than the hybrid variety and was associated with reduced grain size. The decline in grain yield was significantly higher under late waterlogging (30%–31%) than early waterlogging (17%–18%). Compared to the hybrid variety Hyvento, the waterlogging‐induced decline in S concentration in grains, husk, and straw was markedly lower in the inbred variety Kredo. While early waterlogging did not affect total grain protein content in either of the varieties, late waterlogging significantly reduced the total grain protein content (18%) in the inbred variety Kredo. Similarly, the grain gliadin content of the hybrid variety was not affected by both waterlogged conditions, whereas 32% and 23% reductions were recorded for the inbred variety under early and late waterlogging, respectively. Nevertheless, waterlogging significantly increased the proportion of S‐poor high‐molecular‐weight glutenin subunits and ω‐gliadin in the inbred variety.ConclusionIt could be inferred from the present study that hybrid winter wheat variety is relatively resistant to waterlogging than the inbred wheat variety, and thereby produces higher grain yield. Efficient uptake and metabolism of S could be one of the mechanisms conferring waterlogging resistance in winter wheat.

Unraveling the mechanism of sulfur nutrition in pigeonpea inoculated with sulfur-oxidizing bacteria.

An investigation was carried out to understand the mechanism(s) involved in the uptake of sulfur (S) as sulfate in pigeonpea following single inoculation of two sulfur-oxidizing bacteria (SOB), Stenotrophomonas maltophilia and Stenotrophomonas pavanii in the treatments amended with either elemental sulfur (S0) or sulfate (S6). Colonization potential and biofilm formation were analyzed through confocal laser scanning microscope (CLSM) and scanning electron microscope (SEM). Furthermore, the effect of seed inoculation on root architecture, expression of genes involved in sulfur oxidation (sox) in bacterial inoculants, and genes involved in sulfate transport in pigeonpea (PpSULTR) were analyzed to correlate with the higher uptake of S in roots and shoots of pigeonpea. Both the SOB exhibited a good colonization potential and biofilm formation on the roots of pigeonpea. Among the 11 sox genes targeted in rhizosphere of pigeonpea, expression was achieved for seven genes, which showed 2-fold increase in treatments inoculated with S. maltophilia and amended with either S6 or S0. The inoculation of S. maltophilia and amendment of S0 led to increased expression of PpSULTR genes by several folds in roots. The inoculation of SOB had a significant influence on non-enzymatic (osmolytes like proline) and enzymatic (PAL, peroxidase, superoxide dismutase, and catalase) levels. The results revealed a significant increase in sulfur uptake in roots and shoots in treatment inoculated with S. maltophilia and amended with S6. The investigation showed that the SOB-mediated over-expression of PpSULTR genes in roots of pigeonpea and sox genes in the rhizosphere were acting synergistically in facilitating higher uptake and translocation of S in roots and shoots of pigeonpea plants.

STUDIES ON PHYSIOLOGICAL AND METABOLIC RESPONSES IN HORSE GRAM (DOLICHOS BIFLORUS L.) INDUCED BY CHROMIUM


 
 
 The current investigation looks on the phyto-toxicity and accumulation of chromium (VI) in Horse gram (Dolichos biflorus L.). Horse gram plants were subjected to chromium (VI) concentrations of (0.00, 0.05, 0.10, 0.20, 0.25, and 0.30 mg/L) at various concentration levels. At higher chromium (0.30 mg/L) concentrations, the foliar toxic symptoms of older leaves included loss of turgor and chlorosis, which eventually manifested as chlorosis in middle-aged leaves after Crizotinib therapy for five days (VI). Chlorosis signs became more significant and twisted to cytotoxicity in places with tapering membrane, slender strands, or weak folding qualities later in the stage, which were characterized by tapering lamellae, thin lenticels, and weak knotting property. On horse bean, Cr (VI) toxic effects has been discovered as reduced crop production, photosynthetic capacity, physiological as well as molecular action, and metabolic dysfunction are all negatively impacted. Iron uptake and accumulation in leaves were reduced by Cr (VI) (0.30 mL/L) in comparison to the control (From 15.60 to 4.35 grammes per kilogramme of dry weight), while boosting sulphur and phosphorous uptake and deposition. When the plants were subjected to the pretreatment for 29 days, the leaves accumulated the greatest amount of Cr (92.12 grammes per kilogramme of dry weight to 10.08 grammes per kilogramme of dry weight), followed by the roots (96.50 grammes per kilogramme of dry weight to 30.20 grammes per kilogramme of dry weight). When consumed in large quantities, the toxic Cr buildup and nutritional deficits that result from the intake of Cr- containing horse gramme can be hazardous to population health, according to the World Health.