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Climatic perturbations have led to the prevalence of abiotic stresses in the environment. With this regard, salt stress imposed adversities are one of the major global challenges in the attainment of sustainable development goals (SDGs) pertaining to crop production. Strategies to cope with salt-induced detrimental impacts through the implementation of gaso-signaling molecules including hydrogen sulfide (H 2 S) has been gaining immense appraisal in recent years. Since H 2 S plays pivotal roles in regulating plant physiological processes including seed germination-to-maturation, senescence and defense-induced responses; it has been the center of attention for many researchers. However, despite its vast potential in the plant system, the role of H 2 S in inducing salt tolerance mechanisms in staple crops including Triticum aestivum (wheat) still remains ambiguous and needs further investigations to scrutinize the underlying mechanisms. Thus, in the present investigation, we attempt to determine the impact of H 2 S application on wheat plants exposed to salt stress conditions. The present study revealed that the H 2 S application synergistically modulated ascorbate-glutathione (AsA-GSH) system, osmolyte accumulation, stomatal dynamics, nutrient levels, source-sink and photosynthesis-related traits in salt stressed wheat plants. The analyzed traits were found correlated with the enhanced growth and yield components, which resulted in improved salt tolerance in H 2 S-treated plants. Further, recent findings would also aid in elucidating the potential role of H 2 S as a significant salt stress-alleviator, and could be implicated as an important crop management strategy to cope up with salt-induced toxicity, which is quite prevalent in natural field conditions. [Display omitted] • H 2 S detained oxidative stress and triggered the AsA-GSH cycle under salt stress in wheat. • H 2 S maintained nutrient homeostasis, source-sink related metabolites, and osmolytes concentrations in salt stressed plants. • Stomatal dynamics and plant-water relations were regulated in H 2 S treated plants under salt stress. • Growth and yield traits were improved in H 2 S supplemented plants under salt stress. [ABSTRACT FROM AUTHOR]

There are global concerns regarding heavy metals-induced pressure on soil ecosystem since past decades due to increasing urban, industrial and agricultural activities. Threat linked with heavy metals with respect to natural environment and humans is a function of their mobility and bioaccessibility. Zinc (Zn) is one of the most transportable and bioavailable heavy metals; hence, its excess levels in soil cause phytotoxicity and decrease yield and quality. Different physicochemical soil factors affect binding of Zn in soil. Moreover, phytoavailability of Zn is coupled with allocation of this element among various fractions of soil. Thus, comprehending the distribution of Zn among diverse soil fractions would assist in developing methods to safeguard human well-being and ecosystem against its lasting accumulation. Further, these soil fractions would impart comprehensive knowledge about chemical, biological and geological processes taking place in soil and in depth information regarding availability of Zn to plants. No doubt, Zn deficiency in plants is more widespread than Zn toxicity; still latter has been described in several regions of the world. Numerous strategies including use of beneficial microbes, mineral nutrients, phytohormones and other agents have been developed to alleviate Zn toxicity in plants. Present review focuses on different Zn forms present in soils and soil factors impacting its phytoavailability to explore a potential link between Zn and soil characteristics. Additionally, various Zn ameliorative approaches along with the prospects of genetic engineering in developing plants tolerant to Zn toxicity have been highlighted. • Zinc bioavailability in soil is influenced by several factors including pH and organic matter. • The toxicity of zinc to plants is dependent on its bioavailability in soil. • Phytohormones mitigate zinc toxicity by augmenting growth and antioxidant potential. • Microbes can ameliorate zinc toxicity plants through the improvement of elemental homeostasis. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Highly fluorescent, water-stable gCN QDs by microwave solvo-thermal technique. • DFT calculations to check structural distortion of gCN sheet with Hg embedded atom. • Bioinspired micro-cartridge via covalent conjugation of gCN QDs to Agarose. • Micro-cartridge binding efficiency is 24.63 mg HgCl 2 per 10 mg gCN on Agarose beads. Abstract Highly fluorescent, water-stable graphitic carbon nitride quantum dots (gCN QDs) synthesized by microwave assisted solvo-thermal technique and characterized via optical spectroscopy, XRD, HR-TEM, Fluorescence spectroscopy, FT-IR and Raman spectroscopy. Synthesized gCN were used for the removal of mercury ions from polluted water samples in a microcartridge format. Density functional theory (DFT) calculations revealed a possible interaction of mercury atoms, and embedment of mercury atom onto synthesized gCN surface lead to moderate structural distortion, reduced band gap and altered dielectric response. Experimentally, the excitation dependent fluorescence of QDs is highly compromised in presence of mercuric (Hg2+) and other ions, validating the theoretical findings, and establishing their use as metal sensor probes. Hg2+ binding ability with gCN QDs was further utilized in developing bioinspired micro-cartridge via covalent conjugation to Agarose microbeads. Micro-cartridge can remove heavy metal contamination from polluted water with a binding efficiency of 24.63 mg HgCl 2 for 10 mg of Agarose-gCN conjugate. [ABSTRACT FROM AUTHOR]

We report a novel fabrication method of functionalised Bridged Rebar Graphene (BRG) onto newly designed nanostructured aptasensor for label free impedimetric sensing of pathogenic bacteria E. coli O78:K80:H11 . The chemical facilitated unscrolling of MWCNT and subsequent bridging with terephthalaldehyde (TPA) to form 3D-hierarchical BRG nanoconstruct exhibited synergistic effect by combining enhanced electrical properties and facile chemical functionality for stable bio-interface. The bacteria-DNA interactions were captured on BRG nanostructured electrode by using specific anti- E.coli DNA aptamer ( K d ~ 14 nM), screened by new in-situ developed SELEX method using phenylboronic acid on microtitre plate. The developed nanostructured aptasensor demonstrated a low detection limit and sensitivity of ~ 10 1 cfu/mL towards E. coli O78:K80:H11 with a dynamic response range from 10 1 to 10 6 cfu/mL in water, juice and milk samples. [ABSTRACT FROM AUTHOR]

The intent of the experiments was to analyze impact of cadmium (Cd) and/or zinc (Zn) on membrane functionality, nutrient acquisition, antioxidant defense, and osmolyte accumulation in nodules of two pigeonpea (Cajanus cajan(L.) Millsp.) genotypes (Sel 85N and P792) with and without arbuscular mycorrhizal (AM) fungusFunneliformis mosseae. Findings demonstrated that accumulation of Cd and Zn in nodules resulted in membrane destabilization, nutrient imbalance, increased antioxidant enzyme activities [superoxide dismutase (SOD), catalase (CAT), peroxidase (POX), and glutathione reductase (GR)], and osmoprotectants such as total free amino acids (FAA), total soluble sugars (TSS), proline, and glycine betaine (GB). Cd had higher negative effects than Zn. P792 was comparatively more metal sensitive and displayed higher reductions than Sel 85N. Application of Zn decreased Cd uptake and reduced the phytotoxic effects of Cd. Zn1000in combination withF. mosseaerestored nodular membrane stability; enhanced nutrient pool [phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and iron (Fe)]; and boosted antioxidant enzyme activities and osmolyte synthesis in a genotype-dependent manner. [ABSTRACT FROM AUTHOR]

Cadmium (Cd) is one of the most perilous nonessential heavy metal for plants, owing to its high water solubility and obstruction with various physiological and biochemical processes. It enters food chain via plant uptake from contaminated soil, posing a grave menace to ecosystem and mankind. Green remediation comprises approaches intended at prudent use of natural resources for increasing profits to humans and environment. Arbuscular mycorrhizal (AM) fungi are considered a promising green technological tool for remedial of Cd-polluted soils. They are naturally associated with root system of plants in Cd-contaminated soils, evidencing their tolerance to Cd. AM can decrease Cd uptake by plants broadly through two strategies: (1) extracellular mechanisms involving Cd chelation by root exudates, binding to fungal cell wall/structures or to the glycoprotein glomalin; (2) intracellular means involving transfer via hyphal network, detoxification and vacuolar sequestration mediated by complexation of Cd with glutathione (GSH), phytochelatins (PCs), metallothioneins (MTs) and polyphosphate granules. Additionally, mycorrhizal symbiosis facilitates reconditioning of plants' metabolism primarily through dilution effect, increased water and mineral uptake. Recently, AM-induced remodelling of root cell wall synthesis has been reported to improve plant vigor and survival under Cd stressed environments. The present article highlights Cd impacts on AM growth, its diversity in Cd contaminated soils, and variations among diverse AM fungal species for imparting plant Cd tolerance. The most recent perspectives on AM-mediated Cd tolerance mechanisms in plants, including cellular and molecular studies have also been reviewed for successful utilization of these beneficial microbes in sustainable agriculture. [ABSTRACT FROM AUTHOR]

Cadmium (Cd) and zinc (Zn) are commonly associated with each other due to their similar geochemical behavior. Cadmium is a potentially toxic metal and Zn plays important role in counteracting Cd toxicity in plants. Arbuscular mycorrhizal (AM) fungi are known to be associated with plant metal tolerance. Aim of the study was to analyze Cd and Zn uptake and translocation and their impact on yield components in pigeonpea [Cajanus cajan (L.) Millsp.] genotypes under single and combined applications with and without Glomus mosseae. Cadmium and Zn contents varied greatly (roots > shoots > seeds). Yield parameters (number of flowers, seed weight, harvest index) were impaired with increasing Cd and Zn levels although Cd caused more reductions. ‘Sel 85N’ had lower metal accumulation and higher yield than ‘P792’. Combination of Cd25+Zn1000 was most effective in decreasing Cd uptake and increasing yield. Association with G. mosseae was significantly beneficial in ameliorating metal toxicity. [ABSTRACT FROM AUTHOR]

We report biolayer interferometry based in-vitro selection technique (BLI-SELEX) for fishing out specific aptamers against E. coli Shiga toxin subtypes viz., stx1 & stx2 via epitopic peptides. BLI-SELEX is a one-step technique for rapidly generating aptamers against protein biomarkers in a microtiter plate format, obliterating the need for multiple enrichment rounds to harvest high-affinity aptamers as in conventional SELEX. Two unique aptamers selected against stx1 & stx2 with picomolar K d (~47 pM & ~29 pM, respectively) were successfully used to fabricate voltammetric diagnostic assay via immobilization onto chitosan exfoliated 2D tungsten diselenide (WSe 2) nanosheet platform. These aptamers modified nanosensors showed high sensitivity of ~ 5.0 μA ng-1 mL, a dynamic response range from 50 pg mL-1 to 100 ng mL-1, with a detection limit of 44.5 pg mL-1 & 41.3 pg mL-1 for stx subtypes, respectively and showed low cross-reactivity in spiked urine, serum and milk samples. The synergistic effect of selective aptamers & high sensitivity imparted by 2D transition metal dichalcogenide (TMD) highlights the superior potential of a fabricated nanosensor for bacterial toxin detection. • BLI SELEX for high affinity anti-shiga toxin aptamers. • Single microplate format without multiple enrichment rounds. • Aptamers targeting shiga toxin subtypes of K d ~47 & ~29 pM were screened. • Apta/Chito-WSe 2 voltammetric detection platform with dynamic response range. • LOD of 44.5 & 41.3 pg mL-1 for stx1 & stx2 with minimal cross-reactivity. [ABSTRACT FROM AUTHOR]

The development of a label-free impedimetric aptasensor is reported for rapid and sensitive detection of Escherichia coli O157:H7 employing boron-carbon nanorods decorated by nickel nanoparticles (BC-Ni) nanostructured platform. These highly electroactive BC-Ni nanorods were synthesized to increase the sensitivity of the sensor surface and subsequently functionalized with a specific anti-E. coli O157:H7 aptamer (Kd = 69 nM) as bio-recognition moiety. This fully characterized high-affinity DNA aptamer against the bacteria was selected using a facile microtiter plate-based cell-SELEX methodology. The fabricated electrochemical aptasensor is demonstrated to detect E. coli O157:H7 selectively with a detection limit of 10 cfu and a dynamic detection range of 100 to 105 cfu in water, juice, and fecal samples. [ABSTRACT FROM AUTHOR]

Review: 146 refs. [ABSTRACT FROM AUTHOR]

Growth of multifunctional nanohybrids with ordered porous structures is a much sought aspect for real time applications of mesoporous materials in detecting trace biomarkers in exhaled breathe. Here, we demonstrate the utilization of mesoporous silica (KIT-6) exhibiting 3-D porous structure as hard template for the development of Indium loaded WO 3 -SnO 2 ordered nanohybrids by nanocasting approach. The negative replicated structure of In/WO 3 -SnO 2 was tested for selective trace detection of important Volatile Organic Compounds (VOCs) present in human breathe (acetone, ethanol, formaldehyde, trimethylamine and 1,3,5 trimethylbenzene). The sensing results illustrate that In/WO 3 -SnO 2 (2 wt% In, R a /R g = 66.5) showed 2.12 and 3.16 times better response than pure WO 3 -SnO 2 (R a /R g = 31.3) and In/SnO 2 (R a /R g = 21.1) nanocomposite for 50 ppm acetone gas at a relatively lower operating temperature. The hybrid nanocomposite In(2)/WO 3 -SnO 2 was able to detect 1 ppm trace acetone gas with a significant rapid response (4 s) and recovery time (2 s) along with linear response, high stability, good reversibility and excellent selectivity. The present study reported rapid detection of important VOCs in a dynamic range from 1 to 500 ppm and has potential application in designing a futuristic handheld nanostructured device with enhanced gas-sensing performance. [ABSTRACT FROM AUTHOR]

The climatic changes have great threats to sustainable agriculture and require efforts to ensure global food and nutritional security. In this regard, the plant strategic responses, including the induction of plant hormones/plant growth regulators (PGRs), play a substantial role in boosting plant immunity against environmental stress-induced adversities. In addition, secondary metabolites (SMs) have emerged as potential 'stress alleviators' that help plants to adapt against environmental stressors imposing detrimental impacts on plant health and survival. The introduction of SMs in plant biology has shed light on their beneficial effects in mitigating environmental crises. This review explores SMs-mediated plant defense responses and highlights the crosstalk between PGRs and SMs under diverse environmental stressors. In addition, genetic engineering approaches are discussed as a potential revenue to enhance plant hormone-mediated SM production in response to environmental cues. Thus, the present review aims to emphasize the significance of SMs implications with PGRs association and genetic approachability, which could aid in shaping the future strategies that favor agro-ecosystem compatibility under unpredictable environmental conditions. [Display omitted] • SMs induce plant defense mechanisms under environmental stresses. • PGRs-mediated SMs production could aid in developing stress resilient crops. • Genetic manipulation of PGRs could assist in SMs modulation to confer stress tolerance. [ABSTRACT FROM AUTHOR]

A nanohybrid mediated SERS substrate was prepared by in-situ synthesis and assembly of gold nanoparticles (AuNPs) on exfoliated nanosheets of tungsten disulfide (WS2) to form plasmonic hotspots. The nanohybrid surface was functionalized with specific aptamers which imparted high selectivity for the cardiac marker myoglobin (Mb). The fabricated aptasensor was read by SERS using a 532 nm laser and demonstrated significant signal enhancement, and this allowed Mb to be determined in the 10 f. mL−1 to 0.1 μg mL−1 concentration range. The study presents an approach to synergistically exploit the unique chemical and electromagnetic properties of both WS2 and AuNPs for many-fold enhancement of SERS signals.Schematic presentation of a nanohybrid-mediated SERS substrate prepared by in-situ assembly of gold nanoparticles (AuNPs) reduced on exfoliated nanosheets of tungsten disulfide (WS2) to form plasmonic hot spots. Specific aptamers immobilized on the SERS surface impart high sensitivity and selectivity for the cardiac marker myoglobin (Mb). [ABSTRACT FROM AUTHOR]