Endophytic bacilli from Cyamopsis tetragonoloba (L.) Taub. induces plant growth and drought tolerance.

Cyamopsis tetragonoloba (L.) Taub. (guar) is a commercially important crop known for its galactomannan content in seeds. Drought stress is a significant global concern that compromises the productivity of major legumes including guar. The endophytic microbes associated with plants play a significant role in enhancing plant growth and modulating the impact of abiotic stress(s). The present study involved the isolation of 73 endophytic bacteria from the guar seeds of drought-tolerant (RGC-1002 and RGC-1066) and sensitive (Sarada and Varsha) varieties. Based on multiple PGP attributes and drought tolerance, at 50% PEG6000 w/v, 11 efficient isolates were selected and identified through 16S rRNA gene sequencing. Isolates belonging to ten different species of bacilli including Cytobacillus oceanisediminis, Mesobacillus fermenti, Peribacillus simplex from sensitive and Bacillus zanthoxyli, B. safensis, B. velezensis, B. altitudinis, B. licheniformis, B. tequilensis, and B. paralicheniformis isolated from tolerant varieties. A greenhouse experiment with a drought-sensitive guar variety demonstrated that inoculation of selected isolates showed comparatively better plant growth, higher relative water content (RWC), decreased carbon isotope discrimination ratio (Δ13C), increased chlorophyll, carotenoids, anthocyanin, and proline content, decreased malondialdehyde (MDA) and modulated defense enzymes as compared to their uninoculated controls. Tolerant variety isolates B. tequilensis NBRI14G and B. safensis NBRI10R showed the most promising results in improving plant growth and also drought stress tolerance in guar plants. This study represents for the first time that seed endophytic bacterial strains from guar can be utilized to develop the formulation for improving the productivity of guar under drought-stress conditions.

Paenibacillus lentimorbus alleviates nutrient deficiency-induced stress in Zea mays by modulating root system architecture, auxin signaling, and metabolic pathways.

KEY MESSAGE: Paenibacillus lentimorbus reprograms auxin signaling and metabolic pathways for modulating root system architecture to mitigate nutrient deficiency in maize crops. The arable land across the world is having deficiency and disproportionate nutrients, limiting crop productivity. In this study, the potential of plant growth-promoting rhizobacteria (PGPR) viz., Pseudomonas putida, Paenibacillus lentimorbus, and their consortium was explored for growth promotion in maize (Zea mays) under nutrient-deficient conditions. PGPR inoculation improved the overall health of plants under nutrient-deficient conditions. The PGPR inoculation significantly improved the root system architecture and also induced changes in root cortical aerenchyma. Based on plant growth and physiological parameters inoculation with P. lentimorbus performed better as compared to P. putida, consortium, and uninoculated control. Furthermore, expression of auxin signaling (rum1, rul1, lrp1, rtcs, rtcl) and root hair development (rth)-related genes modulated the root development process to improve nutrient acquisition and tolerance to nutrient-deficient conditions in P. lentimorbus inoculated maize plants. Further, GC-MS analysis indicated the involvement of metabolites including carbohydrates and organic acids due to the interaction between maize roots and P. lentimorbus under nutrient-deficient conditions. These findings affirm that P. lentimorbus enhance overall plant growth by modulating the root system of maize to provide better tolerance to nutrient-deficient condition.

Endophytic Alkalotolerant Plant Growth-Promoting Bacteria Render Maize (Zea mays L.) Growth Under Alkaline Stress.

This study investigates the role of bacterial endophytes from extreme alkaline environments in alleviating alkaline stress and plant development. Stressful environmental factors, such as soil acidity and alkalinity/sodicity, frequently affect plant development. In the present study, alkaline-tolerant endophytic strains were isolated from three plant species Saccharum munja, Calotropis procera, and Chenopodium album, and 15 out of the total of 48 isolates were selected for further examination of their abiotic stress tolerance. Molecular analysis based on 16S rRNA gene sequencing revealed strains from Enterobacter, Acinetobacter, Stenotrophomonas, Bacillus, Lysinibacillus, and Mammaliicoccus genera. Out of 15 isolates based on their quantitative PGP traits and abiotic stress tolerance, 6 were finally selected for greenhouse experiments. Under alkaline conditions, results demonstrated that the strains from the genera Enterobacter, Bacillus, Stenotrophomonas, and Lysinibacillus had beneficial effects on maize growth. These findings suggest that using a combination of bacteria with multiple plant growth-promoting attributes could be a sustainable approach to enhance agricultural yield, even in a challenging alkaline environment. The study concludes that the application of bacterial endophytes from plants growing in extremely alkaline environments might provide other plants with similar stress-tolerance abilities. The outcome of the study provides a basis for future exploration of the mechanisms underlying endophyte-induced stress tolerance.

Bio-stimulants from medicinally and nutritionally significant plant extracts mitigate drought adversities in Zea mays through enhanced physiological, biochemical, and antioxidant activities.

Drought stress poses a substantial threat to global plant productivity amid increasing population and rising agricultural demand. To overcome this problem, the utilization of organic plant growth ingredients aligns with the emphasis on eco-friendly farming practices. Therefore, the present study aimed to assess the influence of 30 botanical extracts on seed germination, seedling vigor, and subsequent maize plant growth under normal and water deficit conditions. Specifically, eight extracts showed significant enhancement in agronomical parameters (ranging from ∼2 % to ∼ 183 %) and photosynthetic pigments (ranging from ∼21 % to âˆ¼ 195 %) of seedlings under drought conditions. Extended tests on maize in a greenhouse setting confirmed that the application of six extracts viz Moringa oleifera leaf (MLE), bark (MBE), Terminalia arjuna leaf (ALE), bark (ABE), Aegel marmelos leaf (BLE), and Phyllanthus niruri leaf (AmLE) improved plant growth and drought tolerance, as evident in improved physio-biochemical parameters. GC-MS analysis of the selected extracts unveiled a total of 51 bioactive compounds, including sugars, sugar alcohols, organic acids, and amino acids, and might be playing pivotal roles in plant acclimatization to drought stress. In conclusion, MLE, MBE, BLE, and ABE extracts exhibit significant potential for enhancing seedling establishment and growth in maize under both normal and water deficit conditions.

Molecular dynamics simulation-based study to analyse the properties of entrapped water between gold and graphene 2D interfaces.

Heterostructures based on graphene and other 2D materials have received significant attention in recent years. However, it is challenging to fabricate them with an ultra-clean interface due to unwanted foreign molecules, which usually get introduced during their transfer to a desired substrate. Clean nanofabrication is critical for the utilization of these materials in 2D nanoelectronics devices and circuits, and therefore, it is important to understand the influence of the "non-ideal" interface. Inspired by the wet-transfer process of the CVD-grown graphene, herein, we present an atomistic simulation of the graphene-Au interface, where water molecules often get trapped during the transfer process. By using molecular dynamics (MD) simulations, we investigated the structural variations of the trapped water and the traction-separation curve derived from the graphene-Au interface at 300 K. We observed the formation of an ice-like structure with square-ice patterns when the thickness of the water film was <5 Å. This could cause undesirable strain in the graphene layer and hence affect the performance of devices developed from it. We also observed that at higher thicknesses the water film is predominantly present in the liquid state. The traction separation curve showed that the adhesion of graphene is better in the presence of an ice-like structure. This study explains the behaviour of water confined at the nanoscale region and advances our understanding of the graphene-Au interface in 2D nanoelectronics devices and circuits.

Isolation, chemical characterization, antimicrobial activity, and molecular docking studies of 2,6-dimethoxy benzoquinone isolated from medicinal plant Flacourtia jangomas.

In the present investigation one compound, 2,6-dimethoxy benzoquinone (FJL-1), was isolated from the dichloromethane (DCM) fraction of the organic leaf extract of Flacourtia Jangomas for the first time. The compound structure was elucidated using extensive spectral analysis, including 1H, and 13C NMR. Furthermore, the DPPH and ABTS methods were used to evaluate the antioxidant activity of the organic extract, its fractions, and the isolated compound FJL-1. Antioxidant activity of the petroleum, ether, DCM, and methanol fractions of the organic extract and the isolated compound of F. Jangomas revealed moderate to strong radical scavenging ability. Additionally, the antimicrobial activity of FJL-1 against Staphylococcus aureus (MTCC 737 and MTCC 96 strains) was observed in an inhibition zone size of 21.6 ± 0.6 to 21.7 ± 0.58 mm showing potential inhibitory activity. The isolated compound FJL-1 shows excellent binding with the 2W9S proteins in terms of docking score compared with the drug Trimethoprim, which also exhibited similar types of interaction and potency against S. aureus. The leaves of F. jangomas can be considered a great source for the identification of numerous important phytoconstituents with potential uses in nutrition, aromatherapy, and the pharmaceutical sector. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-024-04002-w.

Strategies to alleviate distortive phase transformations in Li-ion intercalation reactions: an example with vanadium pentoxide.

Chemical and electrochemical Li-ion insertion in transition metal oxides, either via a phase transformation reaction (ions insert into specific crystallographic sites of the host lattice) or a solid solution insertion (ions distribute uniformly throughout the host lattice), enables high energy density electrochemical energy storage. Many phase transformation cathode materials, that undergo two-phase reactions, exhibit high theoretical capacities arising from multi-electron redox reactions. However, challenges in distortive phase transformations and uncontrolled phase nucleation, propagation, segregation, and co-existence continue to limit the energy density, (dis)charging rate performances, and cycling stability of available phase transformation cathode materials. Vanadium pentoxide (V2O5), a classical layered intercalation host material with high theoretical capacity, undergoes irreversible structural changes and capacity fading when intercalating more than one lithium ion per V2O5 unit in its thermodynamically stable phase. Here, we review recent synthetic strategies to alter the V-O connectivity, thereby alleviating distortive phase transformations and promoting solid solution-based Li-ion insertion in V2O5. We also summarize several widely accessible and classical molecular-based analytical tools that can provide local structural dynamics and phase transformation mechanism information on the lithiation of V2O5, including single-crystal X-ray diffraction, infrared and Raman spectroscopy, electron paramagnetic resonance, and nuclear magnetic resonance spectroscopy.

GC-MS fingerprinting, nutritional composition, in vitro pharmacological activities and molecular docking studies of Piper chaba from Uttarakhand region.

This study aimed to evaluate the potential therapeutic effects of Piper chaba (PC) growing in the northern region of India, having differences in the phytochemicals, nutritional content, antimicrobial and antioxidant properties by reducing power assay (RPA), 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, phosphomolybdate assay, and antidiabetic potential by α-amylase assay with change in the geographical location. Outcomes of the gas chromatography-mass spectrometry (GC-MS) analysis revealed that phytochemicals such as piperine (46.69%), kusunokinin (8.9%), and sitostenone (7.57%) are the prominent compounds found in PC. The plant has also shown a good nutritional value, i.e., iron (11.25 mg), calcium (147 mg), and vitamin C (9.30 mg) per 100 g. PC has a higher phenolic content than other species (⁓ 13.75 g/100 g plant powder). Among the four tested bacterial strains, the extract is best responsive toward Escherichia coli (35 ± 0.68 mm) which is more than the standard ciprofloxacin (24 ± 0.8 mm). Similarly, among two tested fungal strains, Saccharomyces cerevisiae shows the best zone of inhibition (ZOI) (27.5 ± 0.8 mm), which is greater than tat of standard amphotericin (20.25 ± 0.28 mm). The DDPH method demonstrated the highest antioxidant activity (⁓ 42.61 ± 1.82 µg/ml). IC50 for the antidiabetic potential of PC was found to be 23.09 ± 0.3 µg/ml against α-amylase assay. A molecular docking study revealed that three compounds, piperine, sitostenone and kusunokinin, showed strong binding affinity toward bacterial tyrosyl-tRNA synthetases, fungal dihydrofolate reductase, and α-amylase, respectively. Therefore, the findings of the current study indicate that PC can be considered as a source of food and medicines, either in the form of traditional preparations or as pure active constituents. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-024-03996-7.

Novel nucleus-localized GRAM protein encoding OsGRAM57 gene enhances salt tolerance through ABA-dependent pathway and modulated carbohydrate metabolism.

GRAM (Glucosyltransferases-like GTPase activators and Myotubularin) domain-encoding proteins play pivotal roles in plant growth and responses to biotic stresses. Yet, their influence on abiotic stress responses has remained enigmatic. This study unveils a novel nucleus-localized OsGRAM57, a GRAM protein-encoding gene and its profound regulatory functions in enhancing salt stress tolerance using Arabidopsis thaliana as a model plant. OsGRAM57-OEX (OsGRAM57-OEX) lines displayed significant enhancement in salt tolerance, modulated physiological, biochemical, K+/Na+ ratios, and enzymatic indices as compared to their wild-type (WT). Furthermore, OsGRAM57-OEX seedlings demonstrate increased levels of endogenous abscisic acid (ABA) and other phytohormones, while metabolic profiling revealed enhanced carbohydrate metabolism. Delving into the ABA signaling pathway, OsGRAM57 emerged as a central regulator, orchestrating the expression of genes crucial for salt stress responses, carbohydrate metabolism, and ABA signaling. The observed interactions with target genes and transactivation assays provided additional support for OsGRAM57's pivotal role. These findings underscore OsGRAM57's positive influence on the ABA pathway and affirm its capacity to enhance salt tolerance through an ABA-dependent pathway and fine-tuned carbohydrate metabolism. In summary, this new study reveals the previously undiscovered regulatory roles of OsGRAM57 in Arabidopsis abiotic stress responses, offering promising ways for strengthening plant resilience in the face of adverse environmental conditions.

Endophytic biofungicide Bacillus subtilis (NBRI-W9) reshapes the metabolic homeostasis disrupted by the chemical fungicide, propiconazole in tomato plants to provide sustainable immunity against non-target bacterial pathogens.

Chemical and microbial fungicides (Bio/fungicide) act differentially on plant systems. The present work assessed the metabolic profile of tomato plants vis-a-vis endophytic diversity after spraying of Propiconazole (PCZ) and endophytic biofungicide Bacillus subtilis (W9). Bio/fungicides were sprayed on tomato plants and evaluated for phenotypic, biochemical, and metabolic profiles after one week. In W9 treatment, a significant increase in relative abundance of several metabolites was observed including sugars, sugar alcohols, fatty-acids, organic-acids, and amino-acids. Polysaccharides and fatty acids showed a significant positive correlation with Rhizobiales, Burkholderiales, Bacillales, and Lactobacillales, respectively (p < 0.05). The PCZ and W9 treated plant's metabolic status significantly affected their resistance to non-target, bacterial pathogen P. syringae. Compared to PCZ and control, W9 treatment reduced the ROS deposition and expression of antioxidants gene GPx, PO (~0.1-1.7fold). It enhanced the genes related to the Phenylpropanoid pathway (∼1.6-5.2 fold), PR protein (~1.2-3.4 fold), and JA biosynthesis (~1.7-4.3 fold), resulting in reduced disease incidence. The results provide novel insights into the effects of endophytic biofungicide and chemical fungicides on the plant's metabolic status, its relation to the endophytes, and role in altering the plant's immune system.

N-Alkyl substituted triazenide-bridged homoleptic iron(II) dimers with an exceptionally short Fe-Fe bond.

Dinuclear transition metal complexes with direct metal-metal interactions have the potential to generate unique reactivities and properties. Using asymmetric triazine ligands HN3tBuR (R = Et, iPr, nBu) featuring different alkyl substituents at 1,3-N centers, we report here the first rational synthesis of 'tetragonal lantern' type Fe(II) triazenides [Fe2(N3tBuR)4] [R = Et (1), iPr (2), nBu (3)] having an exceptionally short Fe-Fe distance (2.167-2.174 Å). Unlike the previously reported lantern structures with related amidinate or guanidinate ligands, highly air-sensitive 1-3 show a lower spin ground state, as indicated by Mössbauer, 1H NMR and DFT studies.