Phyco-synthesis of silver nanoparticles by environmentally safe approach and their applications.

In recent years, there has been an increasing interest in the green synthesis of metallic nanoparticles, mostly because of the evident limitations associated with chemical and physical methods. Green synthesis, commonly referred to as "biogenic synthesis," is seen as an alternative approach to produce AgNPs (silver nanoparticles). The current work focuses on the use of Asterarcys sp. (microalga) for biological reduction of AgNO3 to produce AgNPs. The optimal parameters for the reduction of AgNPs were determined as molarity of 3 mM for AgNO3 and an incubation duration of 24 h at pH 9, using a 20:80 ratio of algal extract to AgNO3. The biosynthesized Ast-AgNPs were characterised using ultraviolet-visible spectroscopy (UV-Vis), zeta potential, scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), and high-resolution transmission electron microscopy (HR-TEM) with selected area electron diffraction (SAED) patterns. The nanoparticles exhibited their highest absorption in the UV-visible spectra at 425 nm. The X-ray diffraction (XRD) investigation indicated the presence of characteristic peaks at certain angles: 38.30° (1 1 1), 44.40° (2 0 0), 64.64° (2 2 0), and 77.59° (3 1 1) according to the JCPDS file No. 04-0783. Based on SEM and TEM, the Ast-AgNPs had an average size of 35 nm and 52 nm, respectively. The zeta potential was determined to be - 20.8 mV, indicating their stability. The highest antibacterial effectiveness is shown against Staphylococcus aureus, with a zone of inhibition of 25.66 ± 1.52 mm at 250 µL/mL conc. of Ast-AgNPs. Likewise, Ast-AgNPs significantly suppressed the growth of Fusarium sp. and Curvularia sp. by 78.22% and 85.05%, respectively, at 150 µL/mL conc. of Ast-AgNPs. In addition, the Ast-AgNPs exhibited significant photocatalytic activity in degrading methylene blue (MB), achieving an 88.59% degradation in 120 min, revealing multiple downstream applications of Ast-AgNPs.

Acclimation response and management strategies to combat heat stress in wheat for sustainable agriculture: A state-of-the-art review.

Unpredicted variability in climate change on the planet is associated with frequent extreme high-temperature events impacting crop yield globally. Wheat is an economically and nutritionally important crop that fulfils global food requirements and each degree rise in temperature results in ∼6% of its yield reduction. Thus, understanding the impact of climate change, especially the terminal heat stress on global wheat production, becomes critically important for policymakers, crop breeders, researchers and scientists to ensure global food security. This review describes how wheat perceives heat stress and induces stress adaptation events by its morpho-physiological, phenological, molecular, and biochemical makeup. Temperature above a threshold level in crop vicinity leads to irreversible injuries, viz. destruction of cellular membranes and enzymes, generation of active oxygen species, redox imbalance, etc. To cope with these changes, wheat activates its heat tolerance mechanisms characterized by hoarding up soluble carbohydrates, signalling molecules, and heat tolerance gene expressions. Being vulnerable to heat stress, increasing wheat production without delay seeks strategies to mitigate the detrimental effects and provoke the methods for its sustainable development. Thus, to ensure the crop's resilience to stress and increasing food demand, this article circumscribes the integrated management approaches to enhance wheat's performance and adaptive capacity besides its alleviating risks of increasing temperature anticipated with climate change. Implementing these integrated strategies in the face of risks from rising temperatures will assist us in producing sustainable wheat with improved yield.

Toxicity evaluation of iron oxide nanoparticles to freshwater cyanobacteria Nostoc ellipsosporum.

The extensive usage of iron oxide nanoparticles (FeO NPs) in commercial and biomedical applications raises the risk of releasing their remains into the aquatic ecosystems and this could possibly cause cytotoxic effects on aquatic organisms. Thus, the toxicity assessment of FeO NPs on cyanobacteria, which are primary producers at the bottom of food chain in aquatic ecosystems, is essential to gain information about the potential ecotoxicological threat on aquatic biota. The present study investigated the cytotoxic effects of FeO NPs on Nostoc ellipsosporum using different concentrations (0, 10, 25, 50 and 100 mg L-1) to track the time-dependent and dose-dependent effects and compared with its bulk equivalent. In addition, the impacts of FeO NPs and bulk counterpart on cyanobacterial cells were assessed under nitrogen as well as nitrogen-deficient conditions, because of ecological role of cyanobacteria in nitrogen fixation. The study revealed that the highest protein content was observed in the control in both types of BG-11 media compared to treatments of nano and bulk particles of Fe2O3. A 23% reduction in protein in nanoparticle treatment and a 14% reduction in bulk treatment at 100 mg L-1 was observed in BG-11 medium. At same concentration, in BG-110 media, this decline was even more intense with 54% reduction in nanoparticle and a 26% reduction in bulk. Catalytic activity of catalase and superoxide dismutase was found to be linearly correlated with the dose concentration for nano and bulk form in BG-11 as well as BG-110 media. The increased levels of lactate dehydrogenase act as biomarker of the cytotoxicity brought on by nanoparticles. Optical, scanning electron, and transmission electron microscopy all demonstrated the cell entrapment, nanoparticle deposition on the cell surface, cell wall collapse and membrane degradation. A cause for concern is that nanoform was found to be more hazardous than bulk form.

Toxicity of boron nitride nanoparticles influencing bio-physicochemical responses in freshwater green algae.

Boron nanoparticles have emerged as promising nanomaterials with a wide array of applications in the biomedical, industrial, and environmental fields. However, the potential impact of these nanoparticles on aquatic organisms is not yet known. In the present study, the comparative impact of boron nitride nanoparticles and its bulk form is investigated on two freshwater algae. For this purpose, the effect on the physiological index, cellular morphology, and biochemistry profiles are examined. In Chlorella vulgaris, nano form of boron nitride is found to reduce the growth more (40%) than its bulk form (with ~ 25% growth reduction) at 50 mgl-1 treatment level. While in case of Coelastrella terrestris, 40% reduction under nano form and 33.33% reduction under bulk form is observed at 100 mgl-1 of boron nitride. Chlorophyll and carotenoid levels were also reduced under nanoparticles compared to the bulk. Proline, lactate dehydrogenase, and malondialdehyde assay were found significantly high under nanoparticle exposure. Additionally, increased catalase and superoxide dismutase enzyme activity under nanoparticle exposure revealed that the antioxidant system was activated in both the algae to eliminate the adverse influence of reactive oxygen species. The shading effect and aggregation of nanoparticles over the surface of algal cells are also important factors in attributing toxicity which are confirmed through the compound, TEM, and SEM micrographs. The study suggests that the nano form is more toxic than the bulk form and toxicity is concentration-dependent.

Nano-strategies as Oral Drug Delivery Platforms for Treatment of Cancer: Challenges and Future Perspectives.

Oral drug administration is the oldest and widely used method for drug administration. The objectives behind developing an oral drug delivery for the treatment of cancer are to achieve low cost treatment by utilizing novel techniques to target cancer through gut-associated lymphoid tissue (GALT) and to enhance patient comfort and compliance through a hospital-free treatment leading to "Chemotherapy at Home." Unfortunately, due to the physiological environment of the GIT and physicochemical properties of drug candidate, the efficacy of oral drug delivery methods is limited in the treatment of cancer. Due to their low hydrophilicity, high P-gp efflux and restricted intestinal permeability most of the anti-cancer drugs fail to achieve oral bioavailability. The review focuses on the efforts, challenges, opportunities and studies conducted by scientists worldwide on the oral administration of anticancer medications via nanocarriers such as liposomes, SLNs and dendrimers, because of their potential to overcome the epithelial barrier associated with GALT, as well as the applications of different polymers in targeting the cancer. The oral delivery can set newer horizons in cancer therapy to make it more patient friendly.

Chitosan nanomaterials: A prelim of next-generation fertilizers; existing and future prospects.

Global agriculture is urgently seeking ways to mitigate the detrimental effects of conventional chemical fertilizers on the environment. Biodegradable, eco-friendly, renewable energy-sourced next-generation fertilizers could be an answer, allowing for improved nutrient use efficiency and a lower environmental footprint. During the last decade, agricultural research on chitosan nanomaterials (NMs) has expanded, demonstrating their usefulness in enhancing agricultural output not only as plant immune boosters but also via slow, controlled and target delivery of nutrients to plants. Chitosan NMs natively act as an abundant nutrient source of C (54.4-47.9 wt%), O (42.3-30.19 wt%), N (7.6-5.8 wt%), and P (6.1-3.4 wt%) to plants. Moreover, chitosan NMs can further functionalized by more nutrients payloads through its functional groups. The current review investigates the technical features of chitosan NMs as prospective next-generation fertilizers based on rationales. The review offers crucial insights into future directions, sources, production capacity of chitosan-based next-generation nanofertilizers for industrial-scale manufacturing.

Glycyrrhiza glabra: An Insight to Nanomedicine.

Glycyrrhiza glabra Linn (Fabaceae), commonly known as Licorice/Liquorice, Mulahatti; is an undershrub. The dried, peeled or unpeeled underground stems and roots are used for the treatment of upper respiratory tract ailments, immunodeficiency, endocrine disorders, skin, liver, joint and heart diseases. Medicinal properties of this plant are enormous and offer it as one of the greatest candidates in the field of Nanomedicine. The Nanomedicine has dedicated to safeguard and upgrade human health using the nanotechnology. Bioactive constituents of this plant perform versatile pharmacological actions and can be used as good Bioanalytical tools. Therefore, an updated overview on current knowledge of green synthesis of nanoparticles (NPs), nanoformulations and surface modification using G. glabra is provided here in order to explore its therapeutic potential especially antifungal and antibacterial activities. In our lab, we have synthesized silver nanoparticles (Ag NPs) using leaves and rhizome parts of G. glabra.

Slow-release Zn application through Zn-chitosan nanoparticles in wheat to intensify source activity and sink strength.

Source activity and sink strength are important aspects to measure growth and yield in wheat. Despite zinc's extended functions in the amendment of plant metabolic activities, critical research findings are missing on mapping the elusive interplays of slow-release zinc (Zn) application from nanoparticles (NPs) in crop plants. The present study reports that slow-releasing Zn application through Zn-chitosan NPs bestows myriad effects on source activity and sink strength in wheat plants. Herein, effects of foliar application of Zn-chitosan NPs (0.04-0.16%; w/v) at booting stage of wheat crop were evaluated to quantify the source sink potential compared to ZnSO4. Zn-chitosan NPs endowed elevated source activity by up-regulating cellular redox homeostasis by improving the antioxidant status, cellular stability and higher photosynthesis. Cognately, in the field experiment, NPs (0.08-0.16%, w/v) significantly spurred sink strength by up-regulating starch biosynthesis enzymes viz. sucrose synthase (SUS), invertase (INV), ADP-glucose pyrophosphorylase (AGPase), soluble starch synthase (SSS) and accumulated more starch in developing wheat grains. Concomitantly, higher spike lengths without awns, significantly higher number of grains/spike, test weight (24% more than ZnSO4 treatment), yield (21% more than ZnSO4 treatment), biological yield and harvest index quantified the higher sink size to further validate the better sink strength in slow-release Zn application via chitosan NPs.

Mechanism of nanotoxicity in Chlorella vulgaris exposed to zinc and iron oxide.

Usage of nanoparticle in various products has increased tremendously in the recent past. Toxicity of these nanoparticles can have a huge impact on aquatic ecosystem. Algae are the ideal organism of the aquatic ecosystem to understand the toxicity impact of nanoparticles. The present study focuses on the toxicity evaluation of zinc oxide (ZnO) and iron oxide (Fe2O3) nanoparticles towards freshwater microalgae, Chlorella vulgaris. The dose dependent growth retardation in Chlorella vulgaris is observed under ZnO and Fe2O3 nanoparticles and nanoform attributed more toxicity than their bulk counterparts. The IC50 values of ZnO and Fe2O3 nanoparticles was reported at 0.258 mg L-1 and 12.99 mg L-1 whereas, for the bulk-form, it was 1.255 mgL-1 and 17.88 mg L-1, respectively. The significant decline in chlorophyll content and increase in proline content, activity of superoxide dismutase and catalase, indicated the stressful physiological state of microalgae. An increased lactate dehydrogenase level in treated samples suggested membrane disintegration by ZnO and Fe2O3 nanoparticles. Compound microscopy, scanning electron microscopy and transmission electron microscopy confirm cell entrapment, deposition of nanoparticles on the cell surface and disintegration of algal cell wall. Higher toxicity of nanoform in comparison to bulk chemistry is a point of concern.

Physio-biochemical responses of wheat plant towards salicylic acid-chitosan nanoparticles.

Sustained source-activity is imperative for vigor plant growth and yield. In present study, physio-biochemical responses of wheat plant contributing to source-activity were measured after application of salicylic acid-chitosan nanoparticles (SA-CS NPs). SA-CS NPs slowly release SA for sustained availability to plant. In seedling bioassay, as compared with salicylic acid (SA), SA-CS NPs incurred up to ~1.5 folds increased activities of seed reserve food remobilizing enzymes for substantial mobilization of reserve food to growing seedlings and enhanced seedling vigor index (SVI) by 1.6 folds. At booting stage, foliar application of SA-CS NPs (0.01-0.08%; w/v) enhanced the activities of superoxide dismutase (1.94 folds), catalase (1.33 folds), peroxidase (1.99 folds) and polyphenol oxidase (1.04 folds) in flag leaf. SA-CS NPs further contrived cellular homeostasis by comforting reactive oxygen species (ROS), malondialdehyde (MDA) and proline contents in flag leaf. SA-CS NPs (0.08%; w/v) significantly increased chlorophylls (a-b) contents (1.46 folds), spike length without awns, spike lets per spike and grain weight per pot as compared with SA. Study categorically explicates that slow release of SA from SA-CS NPs could exert significant effect on source-activity by maneuvering various physio-biochemical responses of wheat plant.

Chitosan-silicon nanofertilizer to enhance plant growth and yield in maize (Zea mays L.).

We report a novel chitosan-silicon nanofertilizer (CS-Si NF) wherein chitosan-tripolyphosphate (TPP) nano-matrix has been used to encapsulate silicon (Si) for its slow release. It was synthesied by ionic gelation method and characterized by dynamic light scattering (DLS), fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and atomic absorption spectrophotometry (AAS). The developed CS-Si NF exhibited slow release of Si and promoted gowth and yield in maize crop. Seeds primed with different concentrations of CS-Si NF (0.04-0.12%, w/v) exhibited up to 3.7 fold increased seedling vigour index (SVI) as compared with SiO2. Its foliar spray significantly induced antioxidant-defence enzymes' activities and equilibrated cellular redox homeostasis by balancing O2-1 and H2O2 content in leaf as compared with SiO2. Application of nanofertilizer (0.01-0.16%, w/v) stirred total chlorophyll content (21.01-25.11 mg/g) and leaf area (159.34-166.96 cm2) to expedite photosynthesis as compared with SiO2. In field experiment, 0.08% CS-Si NF resulted in 43.4% higher yield/plot and 0.04% concentration gave 45% higher test weight as compared with SiO2. Fecund and myriad effects of developed nanofertilizer over SiO2 could be attributed to slow/protective release of Si from nanofertilizer. Overall, results decipher the enormous potential of CS-Si NF for its use as a next generation nanofertilizer for sustainable agriculture.

Cu-chitosan nano-net improves keeping quality of tomato by modulating physio-biochemical responses.

Minimizing the post-harvest losses in fruits and vegetables is one of the challenging tasks in agriculture. To address this issue, we report nano-net of Cu-chitosan nanoparticles (Cu-chitosan NPs) which has the ability to extend the shelf-life of stored tomato. The application of Cu-chitosan NPs (0.01-0.04%) significantly curtailed microbial decay (< 5 versus > 50% in control), physiological loss in weight (14.36 versus 28.13% in control), respiration rate (0.01173 versus 0.01879 g CO2 kg-1 h-1) and maintained fruit firmness (34.0 versus 17.33 N in control) during storage. Further, these NPs significantly retarded loss of titratable acidity, retained total soluble solids, total and reducing sugars, lycopene, ascorbic acid and inhibited polyphenol oxidase. Likewise, NPs effectively preserved L* (lightness), a* (red/green) and b* (blue/yellow) values and maintained organoleptic score. Scanning electron microscopy study confirmed that Cu-chitosan NPs orchestrate into an invisible-intangible nano-net over tomato surface which may plausibly act as a potential barrier at all possible openings (stem scar, cuticle wax, lenticels, and aquaporins) to control microbial infection, moisture loss, gas exchanges and respiration rate. Overall, nano-net extended keeping quality of tomatoes up to 21 days at room temperature (27 ± 2 °C, 55 ± 2% relative humidity).

Chitosan nanofertilizer to foster source activity in maize.

We, herein, report the effect of chitosan nanofertilizer comprising of copper (Cu) and salicylic acid (SA) on source activity in maize. Seed treatment and foliar application of chitosan nanofertilizer significantly up-regulated the source activity in developing maize plants. Seed treatment with nanofertilizer induced 1.6 folds higher seedling vigour index, 1.7-3.0 folds higher activities of reserve food mobilizing enzymes in seedlings as compared with control. Foliar application of nanofertilizer (0.01-0.16%) statistically significantly increased the activities of antioxidant enzymes (1.06-1.91 folds), reduced malondialdehyde content and enhanced chlorophyll contents (2 folds) in leaves. Application of nanofertilizer remarkably induced sucrose translocation (2.5-3.5 folds) in internodes which gives subtle clue of higher remobilization of nutrients towards growing cob. The elusive bioactivities of nanofertilizer can be attributed to slow release and synergistic effects of Cu and SA. We claim that chitosan nanofertilizer has immense potential to promote source activity in maize for higher crop yield.

Simultaneous Estimation of Twenty Eight Phenolic Compounds by a Novel and Expeditious Method Developed on Quaternary Ultra-Performance Liquid Chromatography System with a Photodiode Array Detector.

Plant secondary metabolites including phenolics and flavonoidsare synthesized through phenylpropanoid and phenylpropanoid-acetate pathways and significantly contribute against adverse effect of abiotic and biotic stresses. Herein, we present the development and execution of a novel and expeditious ultra-performance liquid chromatographic-photodiode array (UPLC-PDA) method for qualitative and quantitative analysis of 28 phenolic compounds comprising of flavonoids, phenolic acids, aldehydes and alcohols. The method is able to separate phenolic compounds in just 17 minutes with the separation of isobaric species such as 3,4 dihydroxybenzoic acid and 3,5 dihydroxy benzoic acid; quercetin and taxifolin. Linear curves concentrations ranged from 6-18 µg/mL (3,5 dihydroxy benzoic acid), 4-12 µg/mL (catechin and salicylic acid) and 2-6 µg/mL for rest of the compounds and correlation coefficients were >0.994. The limit of detection (LOD) varied from 0.04-0.45 µg/mL. Cotton root samples were used to assess the method in terms of recovery efficiency (85-120%), precision (0.12-4.09%) and intermediate precision (0.32-4.0%).Phenolics and flavonoidsin root samples of healthy and diseased plants as well as leaf samples of healthy plants were successfully quantified using this novel method without an expensive Mass Spectrometer.

Zinc-functionalized thymol nanoemulsion for promoting soybean yield.

Herein, we report zinc-functionalized thymol nanoemulsion (Zn-TNE) by sonication method and its characterization by DLS, HR-TEM, FEG-SEM-EDS, Cryo-FESEM, FTIR and AAS studies. Zn-TNE treated seeds bestowed better seedling vigor index and higher activities of seed stored food mobilizing enzymes (α-amylase and protease). Foliar application of Zn-TNE (0.01-0.06%, v/v) enhanced defense-antioxidant enzymes activities, balanced reactive oxygen species, induced higher content of chlorophyll-a, b and higher lignin deposition in soybean plants. In the field, Zn-TNE application (0.02-0.06%, v/v) significantly controlled bacterial pustule disease (PEDC value 28-79%) and increased grain yield up to 16.6% as compared with bulk thymol application and up to 50% from control. Disease control and higher yield in soybean could be explained by diverse bioactivities of Zn-TNE in maintaining cellular homeostasis of soybean plants. Study shows that Zn-TNE can further be maneuvered for slow delivery of other micronutrients for higher crop yield.

Zinc encapsulated chitosan nanoparticle to promote maize crop yield.

Zinc deficient/or alkaline soil is globally widespread issue and cultivation of cereals in such soil results in severe depression in plant growth, higher disease incidence and lower grain yield. To address such problems, laboratory synthesized Zn-chitosan nanoparticles (NPs) were evaluated via seed priming and foliar application in maize plants. Zn-chitosan NPs (0.01-0.16%) showed strong in vitro antifungal and seedling growth promotry activities. Further, Zn-chitosan NPs exhibited significant disease control through strengthening of plant innate immunity by elevating antioxidant and defense enzymes, balancing of reactive oxygen species (ROS) and enhancing lignin accumulation. In field, seed treatment and foliar application of developed NPs (0.01-0.16%) significantly controlled Curvularia leaf spot (CLS) disease, increased grain yield from 20.5 to 39.8% and enriched the grain with zinc micronutrient from 41.27 to 62.21 µg/g dw. Results claim that Zn-chitosan NPs could be an effective growth promotry, disease controlling and micronutrient fortifying agent in maize crop.

Salicylic acid functionalized chitosan nanoparticle: A sustainable biostimulant for plant.

In this work, salicylic acid-chitosan nanoparticles (SA-CS NPs) are reported as a biostimulant for promoting plant defense and growth in maize. SA-CS NPs were characterised for colloidal size distribution, functional group, surface chemistry, chemical composition, crystal structure and morphology. Investigation discloses a method of SA-CS NPs synthesis, release profile of SA from SA-CS NPs, antifungal and seedling growth promoting activities. Findings unveil that SA-CS NPs expressed significant physiological-biochemical responses in vitro and in vivo. The responses were recorded as elevated antioxidant-defense enzyme activities, balancing reactive oxygen species (ROS), cell wall reinforcement by lignin deposition, disease control and plant growth in maize. In field, 59.4% control of post-flowering stalk rot (PFSR) disease and 57.8% yield enhancement was evident in SA-CS NPs application compared to SA treatment. The obtained results claim commercial potential of SA-CS NPs as a biostimulant for plant disease control and higher yield.

Thymol nanoemulsion exhibits potential antibacterial activity against bacterial pustule disease and growth promotory effect on soybean.

An antibacterial and plant growth promoting nanoemulsion was formulated using thymol, an essential oil component of plant and Quillaja saponin, a glycoside surfactant of Quillaja tree. The emulsion was prepared by a sonication method. Fifty minutes of sonication delivered a long term stable thymol nanoemulsion which was characterized by dynamic light scattering (DLS), transmission electron microscopy (TEM), cryogenic-field emission scanning electron microscopy (Cryo-FESEM) and fourier transform infra-red (FTIR) spectroscopy. Creaming index, pH and dilution stability were also studied for deliberation of its practical applications. The nanoemulsion (0.01-0.06%, v/v) showed substantial in vitro growth inhibition of Xanthomonas axonopodis pv. glycine of soybean (6.7-0.0 log CFU/ml). In pot experiments, seed treatment and foliar application of the nanoemulsion (0.03-0.06%, v/v) significantly lowered the disease severity (DS) (33.3-3.3%) and increased percent efficacy of disease control (PEDC) (54.9-95.4%) of bacterial pustule in soybean caused by X. axonopodis pv. glycine. Subsequently, significant enhancements of plant growth were also recorded in plants treated with thymol nanoemulsion. This is the first report of a thymol based nanoemulsion obtained using Quillaja saponin as a surfactant. Our study claims that nano scale thymol could be a potential antimicrobial and plant growth promoting agent for agriculture.

Engineered chitosan based nanomaterials: Bioactivities, mechanisms and perspectives in plant protection and growth.

Excessive use of agrochemicals for enhancing crop production and its protection posed environmental and health concern. Integration of advanced technology is required to realize the concept of precision agriculture by minimizing the input of pesticides and fertilizers per unit while improving the crop productivity. Notably, chitosan based biodegradable nanomaterials (NMs) including nanoparticles, nanogels and nanocomposites have eventually proceeded as a key choice in agriculture due to their inimitable properties like antimicrobial and plant growth promoting activities. The foreseeable role of chitosan based NMs in plants might be in achieving sustainable plant growth through boosting the intrinsic potential of plants. In-spite of the fact that chitosan based NMs abode immense biological activities in plants, these materials have not yet been widely adopted in agriculture due to poor understanding of their bioactivity and modes of action towards pathogenic microbes and in plant protection and growth. To expedite the anticipated claims of chitosan based NMs, it is imperative to line up all the possible bioactivities which denote for sustainable agriculture. Herein, we have highlighted, in-depth, various chitosan based NMs which have been used in plant growth and protection mainly against fungi, bacteria and viruses and have also explained their modes of action.

Nanofertilizer for Precision and Sustainable Agriculture: Current State and Future Perspectives.

The increasing food demand as a result of the rising global population has prompted the large-scale use of fertilizers. As a result of resource constraints and low use efficiency of fertilizers, the cost to the farmer is increasing dramatically. Nanotechnology offers great potential to tailor fertilizer production with the desired chemical composition, improve the nutrient use efficiency that may reduce environmental impact, and boost the plant productivity. Furthermore, controlled release and targeted delivery of nanoscale active ingredients can realize the potential of sustainable and precision agriculture. A review of nanotechnology-based smart and precision agriculture is discussed in this paper. Scientific gaps to be overcome and fundamental questions to be answered for safe and effective development and deployment of nanotechnology are addressed.