The completed genome sequence of Pestalotiopsis versicolor, a pathogenic ascomycete fungus with implications for bayberry production.

The pathogenic fungus Pestalotiopsis versicolor is a major etiological agent of fungal twig blight disease affecting bayberry trees. However, the lack of complete genome sequence information for this crucial pathogenic fungus hinders the molecular and genetic investigation of its pathogenic mechanism. To address this knowledge gap, we have generated the complete genome sequence of P. versicolor strain XJ27, employing a combination of Illumina, PacBio, and Hi-C sequencing technologies. This comprehensive genome sequence, comprising 7 chromosomes with an N50 contig size of 7,275,017 bp, a GC content ratio of 50.16%, and a total size of 50.80 Mb, encompasses 13,971 predicted coding genes. By performing comparative genomic analysis between P. versicolor and the genomes of eleven plant-pathogenic fungi, as well as three closely related fungi within the same group, we have gained initial insights into its evolutionary trajectory, particularly through gene family analysis. These findings shed light on the distinctive characteristics and evolutionary history of P. versicolor. Importantly, the availability of this high-quality genetic resource will serve as a foundational tool for investigating the biology, molecular pathogenesis, and virulence of P. versicolor. Furthermore, it will facilitate the development of more potent antifungal medications by uncovering potential vulnerabilities in its genetic makeup.

Bacillus altitudinis-Stabilized Multifarious Copper Nanoparticles Prevent Bacterial Fruit Blotch in Watermelon (Citrullus lanatus L.): Direct Pathogen Inhibition, In Planta Particles Accumulation, and Host Stomatal Immunity Modulation.

The nano-enabled crop protecting agents have been emerging as a cost-effective, eco-friendly, and sustainable alternative to conventional chemical pesticides. Here, the antibacterial activity and disease-suppressive potential of biogenic copper nanoparticles (bio-CuNPs) against bacterial fruit blotch (BFB), caused by Acidovorax citrulli (Ac), in watermelon (Citrullus lanatus L.) is discussed. CuNPs are extracellularly biosynthesized using a locally isolated bacterial strain Bacillus altitudinis WM-2/2, and have spherical shapes of 29.11-78.56 nm. Various metabolites, such as alcoholic compounds, carboxylic acids, alkenes, aromatic amines, and halo compounds, stabilize bio-CuNPs. Foliar application of bio-CuNPs increases the Cu accumulation in shoots/roots (66%/27%), and promotes the growth performance of watermelon plants by improving fresh/dry weight (36%/39%), through triggering various imperative physiological and biochemical processes. Importantly, bio-CuNPs at 100 µg mL-1 significantly suppress watermelon BFB through balancing reactive oxygen species system, improving photosynthesis capacity, and modulating stomatal immunity. Bio-CuNPs show obvious antibacterial activity against Ac by inducing oxidative stress, biofilm inhibition, and cellular integrity disruption. These findings demonstrate that bio-CuNPs can suppress watermelon BFB through direct antibacterial activity and induction of active immune response in watermelon plants, and highlight the value of this approach as a powerful tool to increase agricultural production and alleviate food insecurity.

Bio-Functionalized Manganese Nanoparticles Suppress Fusarium Wilt in Watermelon (Citrullus lanatus L.) by Infection Disruption, Host Defense Response Potentiation, and Soil Microbial Community Modulation.

The use of nanofabricated materials is being explored for the potential in crop disease management. Chemically synthesized micronutrient nanoparticles (NPs) have been shown to reduce crop diseases; however, the potential of biogenic manganese NPs (bio-MnNPs) in disease control is unknown. Here, the potential and mechanism of bio-MnNPs in suppression of watermelon Fusarium wilt, caused by Fusarium oxysporum f. sp. niveum (Fon) are reported. Bio-MnNPs are synthesized by cell-free cultural filtrate of a waterrmelon rhizosphere bacterial strain Bacillus megaterium NOM14, and are found spherical in shape with a size range of 27.0-65.7 nm. Application of bio-MnNPs at 100 µg mL-1 increases Mn content in watermelon roots/shoots and improves growth performance through enhancing multiple physiological processes, including antioxidative capacity. Bio-MnNPs at 100 µg mL-1 suppress Fusarium wilt through inhibiting colonization and invasive growth of Fon in watermelon roots/stems, and inhibit Fon vegetative growth, conidiation, conidial morphology, and cellular integrity. Bio-MnNPs potentiate watermelon systemic acquired resistance by triggering the salicylic acid signaling upon Fon infection, and reshape the soil microbial community by improving fungal diversity. These findings demonstrate that bio-MnNPs suppress watermelon Fusarium wilt by multiple ex planta and in planta mechanisms, and offer a promising nano-enabled strategy for the sustainable management of crop diseases.

Recent progress on the heavy metals ameliorating potential of engineered nanomaterials in rice paddy: a comprehensive outlook on global food safety with nanotoxicitiy issues.

Soil contamination with toxic heavy metals (HMs) poses a serious threat to global food safety, soil ecosystem and human health. The rapid industrialization, urbanization and extensive application of agrochemicals on arable land have led to paddy soil pollution worldwide. Rice plants easily accumulate toxic HMs from contaminated agricultural soils, which ultimately accumulated in grains and enters the food chain. Although, physical and chemical remediation techniques have been used for the treatment of HMs-contaminated soils, however, they also have many drawbacks, such as toxicity, capital investment and environmental-associated hazards. Recently, engineered nanomaterials (ENMs) have gained substantial attention owing to their promising environmental remediation applications. Numerous studies have revealed the use of ENMs for reclamation of toxic HMs from contaminated environment. This review mainly focuses on HMs toxicity in paddy soils along with potential health risks to humans. It also provides a critical outlook on the recent advances and future perspectives of nanoremediation strategies. Additionally, we will also propose the interacting mechanism of HMs-ENMs to counteract metal-associated phytotoxicities in rice plants to achieve global food security and environmental safety.

Microbe-oriented nanoparticles as phytomedicines for plant health management: An emerging paradigm to achieve global food security.

Biotic and abiotic environmental stresses affect the production and quality of agricultural products worldwide. The extensive use of traditional preventive measures comprising toxic chemicals has become more problematic due to severe ecotoxicological challenges. To address this issue, engineered nanoparticles (NPs) with their distinct physical and chemical properties has gained scientific attention and can help plants to confront environmental challenges. Despite their ameliorative and beneficial effects, toxicological concerns have been raised about NPs. The recent development of biogenic NPs (bio-NPs) is getting attention in agriculture due to their diverse biocompatibility, better functional efficacy, and eco-friendly nature compared to the recalcitrant NPs, providing a promising strategy for increased crop protection against biotic and abiotic environmental stresses, with the ultimate goal of ensuring global food security. This review summarizes the recent advances in the engineering of bio-NPs with particular emphasis on the functions of bio-NPs in protecting plants from biotic and abiotic environmental stresses, delivery and entry routes of NPs to plant systems, nanotoxicity, and plant physiological/biochemical responses to nanotoxicity. Future perspectives of bio-NP-enabled strategies, remaining pitfalls, and possible solutions to combat environmental challenges via advanced nanotechnology to achieve global food security and a sustainable agricultural system are also discussed.

Dynamic crosstalk between silicon nanomaterials and potentially toxic trace elements in plant-soil systems.

Agricultural soil pollution with potentially toxic trace elements (PTEs) has emerged as a significant environmental concern, jeopardizing food safety and human health. Although, conventional remediation approaches have been used for PTEs-contaminated soils treatment; however, these techniques are toxic, expensive, harmful to human health, and can lead to environmental contamination. Nano-enabled agriculture has gained significant attention as a sustainable approach to improve crop production and food security. Silicon nanomaterials (SiNMs) have emerged as a promising alternative for PTEs-contaminated soils remediation. SiNMs have unique characteristics, such as higher chemical reactivity, higher stability, greater surface area to volume ratio and smaller size that make them effective in removing PTEs from the environment. The review discusses the recent advancements and developments in SiNMs for the sustainable remediation of PTEs in agricultural soils. The article covers various synthesis methods, characterization techniques, and the potential mechanisms of SiNMs to alleviate PTEs toxicity in plant-soil systems. Additionally, we highlight the potential benefits and limitations of SiNMs and discusses future directions for research and development. Overall, the use of SiNMs for PTEs remediation offers a sustainable platform for the protection of agricultural soils and the environment.

Cobalt oxide nanoparticles: An effective growth promoter of Arabidopsis plants and nano-pesticide against bacterial leaf blight pathogen in rice.

Recently, the application of cobalt oxide nanoparticles (Co3O4NPs) has gained popularity owing to its magnetic, catalytic, optical, antimicrobial, and biomedical properties. However, studies on its use as a crop protection agent and its effect on photosynthetic apparatus are yet to be reported. Here, Co3O4NPs were first green synthesized using Hibiscus rosa-sinensis flower extract and were characterized using UV-Vis spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction (XRD), transmission/scanning electron microscopy methods. Formation of the Co3O4NPs was attested based on surface plasmon resonance at 210 nm. XRD assay showed that the samples were crystalline having a mean size of 34.9 nm. The Co3O4NPs at 200 µg/ml inhibited the growth (OD600 = 1.28) and biofilm formation (OD570 = 1.37) of Xanthomonas oryzae pv. oryzae (Xoo) respectively, by 72.87% and 79.65%. Rice plants inoculated with Xoo had disease leaf area percentage (DLA %) of 57.25% which was significantly reduced to 11.09% on infected plants treated with 200 µg/ml Co3O4NPs. Also, plants treated with 200 µg/ml Co3O4NPs only had significant increment in shoot length, root length, fresh weight, and dry weight in comparison to plants treated with double distilled water. The application of 200 µg/ml Co3O4NPs on the Arabidopsis plant significantly increased the photochemical efficacy of PSII (ΦPSII) and photochemical quenching (qP) respectively, by 149.10% and 125.00% compared to the control while the non-photochemical energy dissipation (ΦNPQ) was significantly lowered in comparison to control. In summary, it can be inferred that Co3O4NPs can be a useful agent in the management of bacterial phytopathogen diseases.

Transcriptomic and proteomic profiling reveals toxicity and molecular action mechanisms of bioengineered chitosan­iron nanocomposites against Xanthomonas oryzae pv. oryzae.

Bacterial leaf blight (BLB) pathogen, Xanthomonas oryzae pv. oryzae (Xoo) is the most devastating bacterial pathogen, which jeopardizes the sustainable rice (Oryza sativa L.) production system. The use of antibiotics and conventional pesticides has become ineffective due to increased pathogen resistance and associated ecotoxicological concerns. Thus, the development of effective and sustainable antimicrobial agents for plant disease management is inevitable. Here, we investigated the toxicity and molecular action mechanisms of bioengineered chitosan­iron nanocomposites (BNCs) against Xoo using transcriptomic and proteomic approaches. The transcriptomic and proteomics analyses revealed molecular antibacterial mechanisms of BNCs against Xoo. Transcriptomic data revealed that various processes related to cell membrane biosynthesis, antioxidant stress, DNA damage, flagellar biosynthesis and transcriptional regulator were impaired upon BNCs exposure, which clearly showing the interaction of BNCs to Xoo pathogen. Similarly, proteomic profiling showed that BNCs treatment significantly altered the levels of functional proteins involved in the integral component of the cell membrane, catalase activity, oxidation-reduction process and metabolic process in Xoo, which is consistent with the results of the transcriptomic analysis. Overall, this study suggested that BNCs has great potential to serve as an eco-friendly, sustainable, and non-toxic alternative to traditional agrichemicals to control the BLB disease in rice.

Antimicrobial activity of the biologically synthesized zinc oxide nanoparticles against important rice pathogens.

Global rice production is seriously affected by many abiotic and biotic factors. Among the aggressive rice pathogens, Xanthomonas oryzae pv. oryzae (X. o. pv. oryzae), Bipolaris oryzae (B. oryzae) and Sphaerulina oryzina (S. oryzina) cause bacterial leaf blight, brown leaf spot and narrow brown leaf spot diseases, respectively. The objective of this study was to evaluate the efficacy of biogenic zinc oxide nanoparticles (ZnO NPs) as antimicrobial agent to control rice pathogens. This is the first report of antifungal activity evaluation of ZnO NPs against B. oryzae and S. oryzina. A pre-characterized bacterial strain Escherichia sp. SINT7 was bio-prospected for synthesis of green ZnO NPs. The NPs were confirmed by a characteristic peak measured at 360.96 nm through UV-Vis spectroscopy. Further, the NPs were characterized to elucidate the surface capping molecules, crystallite structure and morphology by various spectroscopic and imaging techniques, which confirmed the spherical shape of NPs with size ranging from 13.07 to 22.25 nm. In vitro studies against X. o. pv. oryzae pathogen depicted the substantial antibacterial activity (up to 25.7 mm inhibition zone at 20 µg/ml NPs concentration). Similarly, ZnO NPs reduced the mycelial growth of B. oryzae and S. oryzina up to 72.68 and 95.78%, respectively at 50 µg/ml concentration on potato dextrose agar plates, while the mycelial biomass reduction was found to be 64.66 and 68. 49% for B. oryzae and S. oryzina, respectively on potato dextrose broth media as compared to control without the addition of NPs. The green ZnO NPs also significantly reduced the fungal spore germination and a disintegration of fungal hyphae for both fungal strains was observed under the microscope as a result of NPs treatment. Hence, it was concluded that biologically synthesized ZnO NPs are potential antimicrobials and could be compared in greenhouse pathogenicity assays with commercial pesticides to control rice pathogens. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-022-01251-y.

Current trends and future prospective in nanoremediation of heavy metals contaminated soils: A way forward towards sustainable agriculture.

Heavy metals (HMs) contamination in agricultural soils is a major concern for global food safety and human health. Although, various in-situ and ex-situ remediation methods have been used for the treatment of HMs contaminated soils, however, they also have many drawbacks viz., capital investment, toxicity, and environmental health hazards. Consequently, there is an urgent need to develop a novel method to ameliorate the toxicity of HMs in agricultural soils. In recent years, nanoparticles (NPs) have gained significant attention due to their potential applications in the environment and agriculture fields. Nanoremediation employs NPs that effectively reduce the contents of toxic HMs in the soil-plant system. Several studies have reported that the application of NPs in HMs-polluted soils, which reduced plant-available HMs concentration soils. However, the long-term efficiency of NPs immobilization is still unclear. Here, we provide details about the toxicity of HMs to environmental systems and potential applications NPs to alleviate the accumulation of HMs in agricultural soils. Finally, we present the mechanistic route of HMs-toxicity alleviation in plants by NPs application as well as their long-term efficiency and future prospects.

Nanoparticle-based amelioration of drought stress and cadmium toxicity in rice via triggering the stress responsive genetic mechanisms and nutrient acquisition.

Cadmium and drought are the most destructive of the abiotic stresses with negative consequences in terms of impaired metabolism, restricted nutrient use efficiency and disruptive photosynthesis of plants. The present study investigated the mitigation strategy of both aforementioned stresses by the application of iron oxide (IONPs) and hydrogel nanoparticles (HGNPs) simultaneously probably for the first time. IONPs were biofabricated by using a locally identified Bacillus strain RNT1, while HGNPs were produced chemically followed by the confirmation and characterization of both NPs through nanomaterials characterization techniques. Results of FTIR and XRD showed the capping of NPs by different functional groups together with their crystalline structure, respectively. SEM and TEM analysis showed the spherical shape along with the particle size ranging from 18 to 94 nm of both NPs, while EDS analysis confirmed the elemental purity of NPs. The results revealed that IONPs-treated rice plants increased biomass, antioxidant enzyme contents, photosynthesis efficiency, nutrient acquisition together with the decrease in reactive oxygen species and acropetal Cd translocation under normal and drought stress conditions as compared with control plants. Furthermore, the expression of the Cd transporter genes, OsHMA2, OsHMA3 and OsLCT1 were curtailed in NPs-treated rice plants under normal and drought stress conditions. The overall significance of the study lies in devising the NPs-based solutions of increasing heavy metal pollution and water availability challenges being faced the farmers around the world.

Biogenic copper nanoparticles produced by using the Klebsiella pneumoniae strain NST2 curtailed salt stress effects in maize by modulating the cellular oxidative repair mechanisms.

The negative effects of salinity on plant growth and physiology are well-established, which is one of the major threats to food security in semi-arid and arid regions of the world. The current research focuses on biosynthesis of copper nanoparticles (CuNPs) from a bacterial strain NST2, which was genetically identified as Klebsiella pneumoniae based on taxonomic identity of 16S rRNA gene. The strain was selected for bioprospecting of CuNPs owing to its Cu tolerance potential. The biologically-synthesized CuNPs were confirmed in culture by using ultraviolet visible spectroscopy. The material characteristics of green CuNPs were further investigated by using Fourier transform infrared spectroscopy, X-ray diffractometer, scanning electron microscopy and transmission electron microscopy, where crystallite size was ranged from 22.44 nm to 44.26 nm and particles were stabilized by various functional groups, such as carbonyl and amine groups. When 100 mg kg-1 of green CuNPs were mixed in saline soil in a pot experiment, the maize plants showed increased root and shoot length (43.52% and 44.06%, respectively), fresh weight (46.05% and 51.82%, respectively) and dry weight (47.69% and 30.63%, respectively) in comparison to control maize plants without CuNPs application. Moreover, green CuNPs at their highest treatment level (100 mg kg-1 of soil) counteracted the lipid peroxidation and oxidative damage in maize plants by promoting the activities of antioxidants and demoting the cellular levels of reactive oxygen species and ionic contents of Na+ and Cl-. Conclusively, biogenic CuNPs is an emerging and promising technique, which could replace traditional methods of salinity management in agricultural soils.

Plant-Microbiome Crosstalk: Dawning from Composition and Assembly of Microbial Community to Improvement of Disease Resilience in Plants.

Plants host diverse but taxonomically structured communities of microorganisms, called microbiome, which colonize various parts of host plants. Plant-associated microbial communities have been shown to confer multiple beneficial advantages to their host plants, such as nutrient acquisition, growth promotion, pathogen resistance, and environmental stress tolerance. Systematic studies have provided new insights into the economically and ecologically important microbial communities as hubs of core microbiota and revealed their beneficial impacts on the host plants. Microbiome engineering, which can improve the functional capabilities of native microbial species under challenging agricultural ambiance, is an emerging biotechnological strategy to improve crop yield and resilience against variety of environmental constraints of both biotic and abiotic nature. This review highlights the importance of indigenous microbial communities in improving plant health under pathogen-induced stress. Moreover, the potential solutions leading towards commercialization of proficient bioformulations for sustainable and improved crop production are also described.

Effect of the Nanoparticle Exposures on the Tomato Bacterial Wilt Disease Control by Modulating the Rhizosphere Bacterial Community.

Ralstonia Solanacearum is one of the most infectious soil-borne bacterial plant pathogens, causing tomato bacterial wilt (TBW). Nanotechnology is an emerging area of research, particularly the application of nanoparticles (NPs) as nanopesticides to manage plant disease is gaining attention nowadays. However, the interaction between NPs and rhizosphere bacterial communities remains largely elusive. This study indicated that metal NPs (CuO, ZnO, and FeO) reduced the incidence of bacterial wilt to varying degrees and affected the composition and structure of the rhizosphere bacterial community. The results revealed that the application of metal oxide NPs can improve the morphological and physiological parameters of TBW infected tomato plants. Among all, CuONPs amendments significantly increase the Chao1 and Shannon index. In the early stage (the second week), it significantly reduces the relative abundance of pathogens. However, the relative abundance of beneficial Streptomyces bacteria increased significantly, negatively correlated with the relative abundance of pathogenic bacteria. In addition, the nano-treatment group will enrich some potential beneficial bacteria such as species from Sphingomonadaceae, Rhizobiaceae, etc. In general, our research provides evidence and strategies for preventing and controlling soil-borne disease tomato bacterial wilt with metal oxide NPs.

Biosynthesis of Silver Chloride Nanoparticles by Rhizospheric Bacteria and Their Antibacterial Activity against Phytopathogenic Bacterium Ralstonia solanacearum.

Ralstonia solanacearum is the most destructive pathogen, causing bacterial wilt disease of eggplant. The present study aimed to develop green synthesis and characterization of silver chloride nanoparticles (AgCl-NPs) by using a native bacterial strain and subsequent evaluation of their antibacterial activity against R. solanacearum. Here, a total of 10 bacterial strains were selected for the biosynthesis of AgCl-NPs. Among them, the highest yield occurred in the synthesis of AgCl-NPs using a cell-free aqueous filtrate of strain IMA13. Ultrastructural observation revealed that the AgCl-NPs were spherical and oval with smooth surfaces and 5-35 nm sizes. XRD analysis studies revealed that these particles contained face-centered cubic crystallites of metallic Ag and AgCl. Moreover, FTIR analysis showed the presence of capping proteins, carbohydrates, lipids, and lipopeptide compounds and crystalline structure of AgCl-NPs. On the basis of phylogenetic analysis using a combination of six gene sequences (16S, gyrA, rpoB, purH, polC, and groEL), we identified strain IMA13 as Bacillus mojavensis. Three kinds of lipopeptide compounds, namely, bacillomycin D, iturin, and fengycin, forming cell-free supernatant produced by strain IAM13, were identified by MALDI-TOF mass spectrometry. Biogenic AgCl-NPs showed substantial antibacterial activity against R. solanacearum at a concentration of 20 µg/mL-1. Motility assays showed that the AgCl-NPs significantly inhibited the swarming and swimming motility (61.4 and 55.8%) against R. solanacearum. Moreover, SEM and TEM analysis showed that direct interaction of AgCl-NPs with bacterial cells caused rupture of cell wall and cytoplasmic membranes, as well as leakage of nucleic acid materials, which ultimately resulted in the death of R. solanacearum. Overall, these findings will help in developing a promising nanopesticide against phytopathogen plant disease management.

Green synthesis of silver nanoparticles transformed synthetic textile dye into less toxic intermediate molecules through LC-MS analysis and treated the actual wastewater.

The illegal disposal of waste from textile industries having recalcitrant pollutants is a worldwide problem with more severity in developing nations. We used an ecofriendly method to synthesize silver nanoparticles (AgNPs) from a locally-isolated bacterial strain Bacillus marisflavi TEZ7 and employed them as photocatalysts to degrade not only synthetic azo dyes but also actual textile effluents followed by phytotoxicity evaluation and identification of degradation molecules. The strain TEZ7 was taxonomically identified through the 16S rRNA gene sequence analysis. Biogenic AgNPs were characterized for stabilizing molecules, crystal structure, size, shape and elemental composition by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) analysis, transmission electron microscopy (TEM), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), respectively. The photocatalytic degradation efficiency of biogenic AgNPs for three azo dyes such as Direct Blue-1, Methyl Red, and Reactive Black-5 ranged between 54.14 and 96.92% after 5 h of sunlight exposure at a concentration of 100 mg/L. Moreover, the actual wastewater treatment analysis revealed that the 100 mg/L dose of AgNPs significantly decreased the concentration of various physico-chemical parameters of textile effluents such as pH, EC, chlorides, sulphates, hardness, BOD, COD, TSS and TDS. Furthermore, six intermediate molecules of methyl red degradation were identified by LC-MS and it was established by a pot study that these degradation molecules have no phytotoxic effects on rice plants. It was concluded that the AgNPs can be used as an efficient and low-cost strategy for the degradation of azo dyes containing textile wastewaters.

Green copper nanoparticles from a native Klebsiella pneumoniae strain alleviated oxidative stress impairment of wheat plants by reducing the chromium bioavailability and increasing the growth.

Chromium (Cr) concentration has been increasing substantially in the environment due to industrial and anthropogenic factors. Plants can absorb Cr and undergo unrestrained oxidation cascades, resulting in cell injury. The ameliorative role of biogenic copper nanoparticles to relieve wheat plants from Cr stress by supporting their growth is still unclear. The present work aims at the biosynthesis and characterization of copper nanoparticles (CuNPs) from a native Klebsiella pneumoniae strain, followed by assessment of wheat growth and physiological responses to CuNPs mixed in Cr-rich soil. The taxonomic rank of K. pneumoniae SN35 was established by the 16 S rRNA gene sequence analysis. The properties of biogenic CuNPs were elucidated by using UV-vis spectroscopy, FTIR, XRD, SEM, and TEM. It was found that 19.01-47.47 nm spherical shaped CuNPs were stabilized by different functional groups produced extracellularly by the strain SN35. The XRD data revealed the crystalline nature of CuNPs as a face-centered cubic structure. Different concentrations of CuNPs (0, 25, 50 and 100 mg kg-1 of soil) were added into the soil mixed with 3.5 mg kg-1 K2Cr2O7 and the pots were placed in a growth chamber for 30 days. The results revealed that the CuNPs, at 25 and 50 mg kg-1 of soil, augmented plant growth, biomass, and cellular antioxidants contents, whereas decreased the reactive oxygen species and Cr translocation from soil to roots and shoots as compared to control plants. Overall, the results revealed that the soil amendment of CuNPs could immobilize the Cr in the soil to prevent its translocation to the upper plant parts and support wheat growth by relieving cellular oxidative stress.

Bioinspired Green Synthesis of Chitosan and Zinc Oxide Nanoparticles with Strong Antibacterial Activity against Rice Pathogen Xanthomonas oryzae pv. oryzae.

Bacterial leaf blight caused by Xanthomonas oryzae pv. oryzae (Xoo) is one of the most devastating diseases, resulting in significant yield losses in rice. The extensive use of chemical antibacterial agents has led to an increase the environmental toxicity. Nanotechnology products are being developed as a promising alternative to control plant disease with low environmental impact. In the present study, we investigated the antibacterial activity of biosynthesized chitosan nanoparticles (CSNPs) and zinc oxide nanoparticles (ZnONPs) against rice pathogen Xoo. The formation of CSNPs and ZnONPs in the reaction mixture was confirmed by using UV-vis spectroscopy at 300-550 nm. Moreover, CSNPs and ZnONPs with strong antibacterial activity against Xoo were further characterized by scanning and transmission electron microscopy, Fourier-transform infrared spectroscopy, and X-ray diffraction. Compared with the corresponding chitosan and ZnO alone, CSNPs and ZnONPs showed greater inhibition in the growth of Xoo, which may be mainly attributed to the reduction in biofilm formation and swimming, cell membrane damage, reactive oxygen species production, and apoptosis of bacterial cells. Overall, this study revealed that the two biosynthesized nanoparticles, particularly CSNPs, are a promising alternative to control rice bacterial disease.

CRISPR-Cas System: History and Prospects as a Genome Editing Tool in Microorganisms.

Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR or more precisely CRISPR-Cas) system has proven to be a highly efficient and simple tool for achieving site-specific genome modifications in comparison to Zinc Finger Nucleases (ZFNs) and Transcription Activator-Like Effector Nucleases (TALENs). The discovery of bacterial defense system that uses RNA-guided DNA cleaving enzymes for producing double-strand breaks along CRISPR has provided an exciting alternative to ZFNs and TALENs for gene editing & regulation, as the CRISPR-associated (Cas) proteins remain the same for different gene targets and only the short sequence of the guide RNA needs to be changed to redirect the site-specific cleavage. Therefore, in recent years the CRISPR-Cas system has emerged as a revolutionary engineering tool for carrying out precise and controlled genetic modifications in many microbes such as Escherichia coli, Staphylococcus aureus, Lactobacillus reuteri, Clostridium beijerinckii, Streptococcus pneumonia, and Saccharomyces cerevisiae. Though, concerns about CRISPR-Cas effectiveness in interlinked gene modifications and off-target effects need to be addressed. Nevertheless, it holds a great potential to speed up the pace of gene function discovery by interacting with previously intractable organisms and by raising the extent of genetic screens. Therefore, the potential applications of this system in microbial adaptive immune system, genome editing, gene regulations, functional genomics & biosynthesis along ethical issues, and possible harmful effects have been reviewed.

Micronutrient-microbiome interplay: a critical regulator of soil-plant health.

The delicate balance between soil micronutrients and the phytobeneficial microbiome is crucial for maintaining soil-plant health. Recently, Dai et al. established a correlation between elemental micronutrients and the soil microbiome that regulates plant quality and productivity, offering innovative and sustainable solutions to increase agricultural production in a changing climate.