IntroductionThis study clarifies the taxonomic identity of Bacillus paralicheniformis MHN12 and maps the genetic foundations of its beneficial traits. It also provides functional insights into the salinity-stress response and paves the way for the development of MHN12 as a potential bioinoculant to enhance crop stress resilience and productivityMethodsThe endophytic strain MHN12, isolated from Vigna radiata, was initially identified as Bacillus licheniformis based on its 16S rRNA sequence. To ascertain its identity and ensure accurate taxonomic classification, a comparative genomic analysis based on genome relatedness indexes and secondary metabolite biosynthetic gene clusters was conducted, involving MHN12 and 22 other B. paralicheniformis strains.Results and discussionThere were high similarities among the strains and antiSMASH revealed the presence of biosynthetic gene clusters specifically fengycin and bacitracin in MHN12 encoded by the genomes of B. paralicheniformis but absent in B. licheniformis. The whole genome analysis of B. paralicheniformis MHN12, focusing on identifying genes contributing to its potential to promote plant growth and abiotic stress tolerance was also performed. Genes linked to chemotaxis, motility, polysaccharide synthesis, plant growth promoting traits, antimicrobial and stress mitigation compounds were annotated. This highlights MHN12's potential to efficiently colonize plants, stimulate their growth, and protect them from environmental stresses and pathogens. In vitro assays also supported the genomic data, demonstrating MHN12's ability to synthesize enzymatic antioxidants and exopolysaccharides (EPS) while retaining plant growth promoting traits under salinity stress. Gas chromatography (GC)-based analysis revealed modulation of plasma membrane lipids aiding MHN12 to combat salt stress.

We report the genome sequence of a novel species of nontuberculous mycobacterium (NTM) belonging to the Mycobacterium terrae complex (MTC). The strain SVM_VP21 was isolated from the mouthwash sample of a healthy human adult residing in Delhi, India. The strain exhibited smooth, cream-coloured colonies on Lowenstein Jensen (LJ) medium after 2 weeks of incubation and could not be identified by Hain’s Genotype Mycobacterium CM/AS line probe assay. Whole genome sequencing (WGS) of SVM_VP21 was performed using Illumina NovaSeq 6000 platform for final identification. The whole genome sequence was assembled using Shovill. Gene annotation was performed by Rapid Annotation using Subsystem Technology (RAST) and Prokaryotic Genome Annotation Pipeline (PGAP). The genome of 4,882,418 bp exhibited 67.3

Nanoparticles (NPs) possess unique properties due to their higher surface-to-volume ratio and reactivity. Negative environmental impact and high cost of traditional modes of synthesis have driven the shift towards utilization of microbes and plants for synthesising NPs, referred as the biological or ‘Green’ synthesis. This study reported extracellular synthesis of copper NPs (CuNPs) using the supernatant of Bacillus licheniformis CPJN13S. The parameters affecting this process were optimized by OFAT approach and were reported to be 5 mM concentration of copper sulfate (CuSO4), 32 h incubation period, 18 h reaction time, 20:20 filtrate/substrate ratio, 7 pH, and 37 °C temperature. CuNPs produced a characteristic UV-Visible absorption peak between 550–650 nm, Z-average of 305.3 nm and zeta potential value of −24.7 mV. SEM and HR-TEM revealed hexagonal shape of NPs having average size of 12.4 nm. XRD peaks obtained at 2θ positions of 45.52°, 56.52°, and 75.34° matched to diffraction from Cu. Antimicrobial assay conducted using 100 μg/mL CuNPs led to highest inhibition of 20.4% (Bacillus subtilis MTCC No. 441) and 43% (Staphylococcus aureus MTCC No. 737), at 21 h and 27 h, respectively. The results suggest that biological synthesis can serve as the eco-friendly alternative of physical and chemical modes of synthesizing CuNPs and can be used to develop highly effective antibacterial agents.

A variety of bacterial genera coexists in natural environments and engages in mutualistic relationships that aid in their development and survival. The objective of this study was to prepare effective microbial consortia comprising potential endophytic bacteria that promote the growth of multiple plant species. These bacteria were isolated from the nodules and roots of Cicer arietinum. Five isolates, namely, CPJN13, CPSN8, CPHN4, CPHN2, and CPReR11, were selected to form the consortia. Compatibility tests were conducted to ensure the suitability of all isolates for consortia formation. Growth profile analyses indicated that the isolates exhibited rapid growth and were compatible. The consortia produced substantial amounts of indole-3-acetic acid, siderophores, and solubilized inorganic phosphate. In the pot experiment, there was significant enhancement in various plant growth parameters, including shoot and root length, as well as fresh and dry weight upon coinoculation of these cultures.

As climate change accelerates and the global population continues to grow, traditional agricultural practices struggle to ensure sustainable food security. Some of the key challenges in agriculture sector includes rising food demand, optimizing nutrient usage, sustainable resource management, and combating the impacts of a changing environmental conditions. Abiotic and biotic stressors encompass soil degradation, salinity, drought, heavy metal contamination, microbial infections, pest infestations, and invasive species, respectively. However, climate challenges such as altered precipitation patterns, temperature extremes, and rising sea levels, exacerbate existing environmental stresses. Nanoparticles (NPs) have potential to alleviate the environmental stresses through mechanisms encompassing enhanced nutrient delivery, soil remediation, and stress tolerance induction in plants, as well as remarkable antimicrobial, pesticidal, and biocontrol capabilities.NPs induce plant resistance against these stresses by strengthening the physical barriers, improving plant photosynthesis and activating plant defense mechanisms. By raising anti-stress chemicals and triggering the expression of defense-related genes, the NPs can also upregulate the expression of genes related to stress.The purpose of this review is to shed light on important developments regarding the potential use of NPs to protect food security and increase the adaptability of agricultural plants to environmental changes. Molecular mechanisms of nanobiotechnology-induced tolerance to abiotic and biotic stresses have also been highlighted.Further research is imperative to delve into the synthesis, dosage optimization, enduring implications, safety considerations, and optimal integration with other techniques for the application of NPs in agricultural plants.

Drought, a detrimental abiotic stress, disturbs many vital processes critical to plant growth and development resulting in subpar crop yield. Unconventional measures such as biofertilizers and nanofertilizers have been reported as reliable solutions to this, however, outcomes vary greatly depending upon the type of organism/particle and its mode of delivery. Seed priming involves treating seeds with organic/inorganic chemicals to ameliorate drought stress by boosting pre-germinative metabolism, maintaining water potential, scavenging free radicals, etc. Therefore, this study determined the effect of biopriming and nanopriming on germination percentage (GP), leaf water status (LWS), proline, malondialdehyde (MDA), hydrogen peroxide (H₂O₂), and survial percentage (SP) of BG-4958 (Drought tolerant) and ICC-1882 (Drought sensitive) chickpea varieties exposed to polyethylene glycol (PEG) induced moderate (5%) and severe drought (10%) at flowering with no drought acting as a control. Experimental setup had three groups, control (untreated), bioprimed with plant growth promoting endophytic bacteria (PGPEB), and nanoprimed with CuNPs synthesised from PGPEB and their chemical counterparts). Crop analysis after 15 DDS (Days to drought stress) revealed that priming significantly altered the physio-biochemical parameters. Consortium and N2X led highest increment in GP and SP for DT and DS varieties, respectively, whereas N1X showed highest increase in LWS of both. Highest accumulation of proline was observed with consortium and N1 (X & Y) in DS variety while only biological CuNPs accumulated proline for DT variety. MDA and H₂O₂ decreased significantly in treated groups thereby reducing oxidative damage with non-significant variations in DT. Lower concentrations of biological CuNPs were found to be more effective in modulating the physio-biochemical machinery of chickpea under drought than their higher concentration as well as chemical counterparts. This study deepens our understanding of the beneficial role of PGPEB and biosynthesized CuNPs in alleviating the adverse effects of drought in chickpea.

Pantoea agglomerans inhabit diverse ecological niches, ranging from epiphytes and endophytes in plants, body of animals, and occasionally in the human system. This multifaceted bacterium contributes substantially to plant growth promotion, stress resilience, and biocontrol but can also act as a pathogen to its host. The genetic determinants underlying these diverse functions remain largely unfathomed and to uncover this phenomenon, nineteen strains of Pantoea agglomerans were selected and analyzed. Genome-to-Genome Distance Calculator (GGDC) which uses the Genome Blast Distance Phylogeny (GBDP) technique to calculate digital DDH values. Phylogenetic analysis via Genome-to-Genome distance, Average Nucleotide Identity, and Amino Acid Identity calculation revealed that all strains belonged to the genus Pantoea. However, strain 33.1 had a lower value than the threshold for the same species delineation. Bacterial Pan Genome Analysis (BPGA) Pipeline and MinPath analysis revealed genetic traits associated with environmental resilience, such as oxidative stress, UV radiation, temperature extremes, and metabolism of distinct host-specific carbohydrates. Protein–protein interactome analysis illustrated osmotic stress proteins closely linked with core proteins, while heavy metal tolerance, nitrogen metabolism, and Type III and VI secretion systems proteins generally associated with pathogenicity formed a separate network, indicating strain-specific characteristics. These findings shed new light on the intricate genetic architecture of Pantoea agglomerans, revealing its adaptability to inhabit diverse niches and thrive in varied environments.

Bacillus paralicheniformis MHN12 possesses a 4,245,453-base pair genome with 45.9% G + C content, including 1 CRISPR, 80 tRNA, 8 rRNA genes, and 4,418 predicted coding sequences . MHN12 exhibits high salinity tolerance and plant growth-promoting abilities, making it a promising bioinoculant for enhancing plant growth in saline soils.

Phytohormone indole-3-acetic acid (IAA) is regarded as the most active physiological member of functional auxins and its production by bacterial endophytes is one of the major contribution towards plant growth promotion. The plant growth promoting endophytic bacteria Pantoea agglomerans CPHN 2 was isolated from Cicer arietinum. This study aimed to optimise the culture conditions for IAA production by P. agglomerans CPHN2 both by one factor at a time (OFAT) and response surface methodology (RSM). Using OFAT, maximum IAA production was achieved with mannitol 10 g/L, yeast extract 1 g/L, tryptophan 600 mg/L, incubation temperature 30 °C, incubation time of 3 days, pH 9.0, at 150 rpm. The presence of IAA in crude extract was confirmed by thin-layer chromatography (TLC) and ultra performance liquid chromatography (UPLC). IAA production was further optimised using central composite design (CCD) with RSM. A three factor CCD test with a quadratic model consisting of set of 20 experiments was finalised. Mannitol 10.23 g/L, yeast extract 1.26 g/L, and tryptophan 701.08 mg/L were optimum for maximum IAA production. The present work exhibited around five fold increase in IAA production by P. agglomerans CPHN2 at alkaline pH. Also, this research shows that the implementation of RSM can serve as an apt tool in determination of optimum conditions for maximum IAA production by bacteria.

Here, we report the draft genome sequence of Pantoea agglomerans CPHN2, an endophyte isolated from nodules of Cicer arietinum (Chickpea) from Hisar, Haryana, India. The genome was 4,839,532 bp and exhibited a GC content of 55.2% and 4,508 genes with 4,468 coding sequences, 1 rRNA, 71 tRNAs, and 1 CRISPR.

Reduced agricultural production as well as issues like nutrient-depleted soils, eutrophication, and groundwater contamination have drawn attention to the use of endophyte-based bioformulations to restore soil fertility. Pantoea agglomerans CPHN2, a non-rhizobial nodule endophyte isolated from Cicer arietinum, exhibited a variety of plant growth-promoting traits. In this study, we used NextSeq500 technology to analyze whole-genome sequence information of this plant growth-promoting endophytic bacteria. The genome of P. agglomerans CPHN2 has a length of 4,839,532 bp and a G + C content of 55.2%. The whole genome comprises three different genomic fractions, comprising one circular chromosome and two circular plasmids. A comparative analysis between P. agglomerans CPHN2 and 10 genetically similar strains was performed using a bacterial pan-genome pipeline. All the predicted and annotated gene sequences for plant growth promotions (PGPs), such as phosphate solubilization, siderophore synthesis, nitrogen metabolism, and indole-3-acetic acid (IAA) of P. agglomerans CPHN2, were identified. The whole-genome analysis of P. agglomerans CPHN2 provides an insight into the mechanisms underlying PGP by endophytes and its potential applications as a biofertilizer.

Plant growth and development are positively regulated by the endophytic microbiome via both direct and indirect perspectives. Endophytes use phytohormone production to promote plant health along with other added benefits such as nutrient acquisition, nitrogen fixation, and survival under abiotic and biotic stress conditions. The ability of endophytes to penetrate the plant tissues, reside and interact with the host in multiple ways makes them unique. The common assumption that these endophytes interact with plants in a similar manner as the rhizospheric bacteria is a deterring factor to go deeper into their study, and more focus was on symbiotic associations and plant–pathogen reactions. The current focus has shifted on the complexity of relationships between host plants and their endophytic counterparts. It would be gripping to inspect how endophytes influence host gene expression and can be utilized to climb the ladder of “Sustainable agriculture.” Advancements in various molecular techniques have provided an impetus to elucidate the complexity of endophytic microbiome. The present review is focused on canvassing different aspects concerned with the multidimensional interaction of endophytes with plants along with their application.

Nanofertilizers effectively deliver the micronutrients besides reducing the phytotoxicity and environmental damage associated with chemical fertilizers. Zinc, an essential micronutrient, is significant for chloroplast development, activation of certain enzymes, and primary metabolism. Nano zinc oxide (ZnO) is the most widely used zinc nanoparticle. Concerns regarding the toxicity of conventional physical and chemical methods of synthesizing the nanoparticles have generated the need for a green approach. It involves the biogenic synthesis of metallic nanoparticles using plants and microorganisms. Microbe-mediated biogenic synthesis of metallic nanoparticles is a bottom-up approach in which the functional biomolecules of microbial supernatant reduce the metal ions into its nanoparticles. This review discusses the biological synthesis of nano-ZnO from microorganisms and related aspects such as the mechanism of synthesis, factors affecting the same, methods of application, along with their role in conferring drought stress tolerance to the plants and challenges involved in their large-scale synthesis and applications.

In the present study, nonrhizobial endophytes were isolated from Pisum sativum and Cicer arietinum from Haryana, India. A total of 355 bacterial endophytes were screened for plant growth promoting traits. Out of all, 96 bacterial endophytes were selected based on morphological characters and multi-PGP traits, and their diversity analyzed by amplified ribosomal DNA restriction analysis. Based on their ARDRA profile, the 25 representative isolates (12 from P. sativum and 13 from C. arietinum), were selected and identified by 16S ribosomal DNA sequencing. Genetic relatedness based on BLAST analysis revealed the similarity of these isolates with members of three prominent phyla, that is, Proteobacteria, Firmicutes, and Actinobacteria. The dominant cluster, Firmicutes, constituted 60% of the isolates, assigned to four different genera, Bacillus, Staphylococcus, Ornithinibacillus, and Lysinibacillus. Phylum α-proteobacteria included two genera, namely Paenochrobactrum and Ochrobactrum and three genera in phylum γ-proteobacteria, namely Pseudomonas, Pantoea and Proteus. The phylum Actinobacteria was constituted of two genera, Microbacterium and Arthrobacter. Bacillus zhangzhouensis, Bacillus safensis, Arthrobacter enclensis from P. sativum and Bacillus haynesii, Paenochrobactrum sp. from C. arietinum are documented as plant growth promoting endophytic bacteria for the first time in the present study. The in vitro and in vivo assessment based on bonitur score revealed that the endophytic isolates Bacillus mojavensis PRN2, Pseudomonas chlororaphis PHN9, B. safensis PRER2, Pseudomonas sp. RCP1, Pseudomonas lini PRN1 and B. haynensii RCP3 from P. sativum and C. arietinum significantly enhanced the plant growth parameters. Therefore, these potential isolates can be further harnessed for preparation of bioformulations to enhance sustainable agriculture.