The ever-increasing demand for agricultural food products, medicine, and other commercial sectors requires new technologies for agricultural practices and promoting the optimum utilization of natural resources. The application of engineered nanomaterials (ENMs) enhance the biomass production and yield of food crop while resisting harmful environmental stresses. Bio-mediated synthesis of ENMs are time-efficient, low-cost, environmentally friendly, green technology. The precedence of using a bio-mediated route over conventional precursors for ENM synthesis is non-toxic and readily available. It possesses many active agents that can facilitate the reduction and stabilization processes during nanoparticle formation. This review presents recent developments in bio-mediated ENMs and green synthesis techniques using plants, algae, fungi, and bacteria, including significant contributions to identifying major ENM applications in agriculture with potential impacts on sustainability, such as the role of different ENMs in agriculture and their impact on different plant species. The review also covers the advantages and disadvantages of different ENMs and potential future research in this field.

In this paper, we present the first publicly available human-annotated dataset of images obtained by the Scanning Electron Microscopy (SEM). A total of roughly 22,000 SEM images at the nanoscale are classified into 10 categories to form 4 labeled training sets, suited for image recognition tasks. The selected categories span the range of 0D objects such as particles, 1D nanowires and fibres, 2D films and coated surfaces as well as patterned surfaces, and 3D structures such as microelectromechanical system (MEMS) devices and pillars. Additional categories such as tips and biological are also included to expand the spectrum of possible images. A preliminary degree of hierarchy is introduced, by creating a subtree structure for the categories and populating them with the available images, wherever possible.

Cerium oxide nanoparticles enhance rice salt tolerance and yield via modulating nitrate reductase activity to improve nitric oxide production.

Salinity is a worldwide factor limiting the agricultural production. Cotton is an important cash crop; however, its yield and product quality are negatively affected by soil salinity. Use of nanomaterials such as cerium oxide nanoparticles (nanoceria) to improve plant tolerance to stress conditions, e.g. salinity, is an emerged approach in agricultural production. Nevertheless, to date, our knowledge about the role of nanoceria in cotton salt response and the behind mechanisms is still rare.

\n CsAKT1 is a key gene involved in PNC improved cucumber salt tolerance.

The present study investigated the beneficial role of selenium-nanoparticles (Se-NPs) in mitigating the adverse effects of soil-salinity on growth and yield of strawberry (Fragaria × ananassa Duch.) plants by maneuvering physiological and biochemical mechanisms. The foliar spray of Se-NPs (10 and 20 mg L) improved the growth and yield parameters of strawberry plants grown on non-saline and different saline soils (0, 25, 50 and 75 mM NaCl), which was attributed to their ability to protect photosynthetic pigments. Se-NPs-treated strawberry plants exhibited higher levels of key osmolytes, including total soluble carbohydrates and free proline, compared with untreated plants under saline conditions. Foliar application of Se-NPs improved salinity tolerance in strawberry by reducing stress-induced lipid peroxidation and HO content through enhancing activities of antioxidant enzymes like superoxide dismutase and peroxidase. Additionally, Se-NPs-treated strawberry plants showed accumulation of indole-3-acetic acid and abscisic acid, the vital stress signaling molecules, which are involved in regulating different morphological, physiological and molecular responses of plants to salinity. Moreover, the enhanced levels of organic acids (e.g., malic, citric and succinic acids) and sugars (e.g., glucose, fructose and sucrose) in the fruits of Se-NPs-treated strawberry plants under saline conditions indicated the positive impacts of Se-NPs on the improvement of fruit quality and nutritional values. Our results collectively demonstrate the definite roles of Se-NPs in management of soil salinity-induced adverse effects on not only strawberry plants but also other crops.Copyright © 2019 Elsevier Ltd. All rights reserved.

干旱是影响水稻产量和品质的常见限制因素之一。氧化铈纳米颗粒在提高作物抗逆中已有广泛报道。然而,氧化铈纳米颗粒是否能提高水稻耐旱能力以及相应的机制目前仍不清除。本研究旨在分析氧化铈纳米颗粒是否可以通过影响活性氧稳态和一氧化氮水平提高水稻抗旱。结果表明,与无纳米材料对照相比,氧化铈纳米颗粒显著增加了干旱胁迫下的水稻幼苗的鲜重(19%, P < 0.05)。同时,干旱胁迫下,氧化铈纳米颗粒处理组水稻叶片的活性氧水平显著低于无纳米材料对照组(82%, P < 0.05),而其叶片一氧化氮荧光信号则显著高于对照组(46%, P < 0.05)。此外,与无纳米材料对照相比,干旱胁迫下,氧化铈纳米颗粒处理组水稻叶片细胞表现出更好的膜完整性,其死细胞数下降70%(P < 0.05)。本研究从活性氧和一氧化氮信号分子的角度初步探索了氧化铈纳米颗粒提高水稻抗旱性的机制,不仅进一步丰富了纳米材料与逆境条件下的作物相互作用的理论基础,而且有利于纳米农业的可持续发展。

Trichoderma spp. are well known biocontrol agents used against phytopathogens. In the present work Trichoderma-mediated Selenium nanoparticles (SeNPs) were synthesized and extent of downy mildew (DM) disease control in pearl millet (PM) was studied. Six species of Trichoderma namely, T. asperellum, T. harzianum, T. atroviride, T. virens, T. longibrachiatum and T. brevicompactum were evaluated in the form of culture filtrate (CF), cell lysate (CL) and crude cell wall (CW) to synthesize SeNPs. All these components produced SeNPs, but CF was significant than CL and CW. The size of SeNPs ranged from 49.5 to 312.5 nm with zeta potential of +3.3 mv to −200 mv. The nanoparticles suppressed the growth, sporulation and zoospore viability of Sclerospora graminicola and these biological activities were inversely proportional to the size of SeNPs. Under greenhouse conditions, application of SeNPs and T. asperellum together enhanced the early plant growth and suppressed DM incidence as compared to their individual application. This study demonstrated the ability of Trichogenic-SeNPs to suppress growth and proliferation of S. graminicola, the incitant of DM of PM and their activity is inversely proportional to size of nanoparticles.

With the advent of rapid evolution of oomycete pathogen lineages, the need for sustainable agriculture practices has become the need of the hour. The late blight of tomato caused by Phytopthora infestans, has recently emerged as one such devastating disease in India that led to huge crop losses. Hence, in the present work seed priming with mycogenic selenium nanoparticles (SeNPs) for elicitation of resistance against tomato late blight disease is investigated. It also aims to understand the defense responses triggered by SeNPs at cellular, biochemical and transcriptomic levels. Enhanced plant growth parameters were observed in bioactive SeNPs-primed tomato plants as compared to control plants. SeNPs-primed and pathogen inoculated plants exhibited a significant protection of 72.9 % against late blight disease. The primed plants also recorded a remarkable accumulation of lignin, callose and hydrogen peroxide that serve as the cellular defense over the control plants. Further, an elevated level of lipoxygenase (LOX), phenylalanine lyase (PAL), β-1,3-glucanase (GLU), superoxide dismutase (SOD) corroborated the biochemical defense in primed plants, which was also reflected in the corresponding transcriptome profiling of the genes encoding the enzymes. Thus, the present study represents an orchestrated correlation between resistance and defense responses incited by SeNPs against tomato late blight disease, which can be used as nano-biostimulant fungicide in protecting tomato plants.Copyright © 2020 Elsevier B.V. All rights reserved.

Reporter systems are routinely used in plant genetic engineering and functional genomics research. Most such plant reporter systems cause accumulation of foreign proteins. Here, we demonstrate a protein-independent reporter system, 3WJ-4 × Bro, based on a fluorescent RNA aptamer. Via transient expression assays in both Escherichia coli and Nicotiana benthamiana, we show that 3WJ-4 × Bro is suitable for transgene identification and as an mRNA reporter for expression pattern analysis. Following stable transformation in Arabidopsis thaliana, 3WJ-4 × Bro co-segregates and co-expresses with target transcripts and is stably inherited through multiple generations. Further, 3WJ-4 × Bro can be used to visualize virus-mediated RNA delivery in plants. This study demonstrates a protein-independent reporter system that can be used for transgene identification and in vivo dynamic analysis of mRNA.

Both metals and metal-based nanoparticles (NPs) can easily accumulate in soil, posing risks for plants and microbes. However, the interaction between NPs and toxic metals coexisting in soil is not yet well understood. Here, we studied the combined effects of ZnO NPs and Cd on sweet sorghum inoculated with or without the arbuscular mycorrhizal (AM) fungus Funneliformis caledonium. Plants were grown in soil amended with ZnO NPs (50, 250, and 500 mg/kg), alone or in combination with 5 mg/kg Cd. The two higher doses of ZnO NPs inhibited plant growth, leading to synergistic toxicity with Cd. However, at the lowest dose, ZnO NPs were non-phytotoxic, displaying antagonistic interactions with Cd on plant growth. When added with high doses of ZnO NPs, Cd significantly increased root Zn concentrations, but decreased shoot Zn concentrations at the low dose. Conversely, all doses of ZnO NPs significantly decreased shoot and root Cd concentrations. Furthermore, high doses of ZnO NPs generally inhibited soil enzyme activities, but Cd addition showed no significant or even stimulative effects, and mitigated the inhibitory effects of ZnO NPs. AM inoculation increased plant growth and P nutrition, and soil enzyme activities. When the low dose of ZnO NPs was added alone or in combination with Cd, AM inoculation decreased shoot Zn concentrations. Our results reveal complex interactions between ZnO NPs and Cd on plant growth and nutrition, plant Zn and Cd accumulation, and soil enzyme activities, while AM inoculation can help diminish the adverse effects induced by ZnO NPs and Cd.Copyright © 2018 Elsevier Ltd. All rights reserved.

The impact of graphene oxide (GO) nanocarbon on soil properties is mixed, with both negative and positive effects. Although it decreases the viability of some microbes, there are few studies on how its single amendment to soil or in combination with nanosized sulfur benefits soil microorganisms and nutrient transformation. Therefore, an eight-week pot experiment was carried out under controlled conditions (growth chamber with artificial light) in soil seeded with lettuce (Lactuca sativa) and amended with GO or nano-sulfur on their own or their several combinations. The following variants were tested: (I) Control, (II) GO, (III) Low nano-S + GO, (IV) High nano-S + GO, (V) Low nano-S, (VI) High nano-S. Results revealed no significant differences in soil pH, dry plant aboveground, and root biomass among all five amended variants and the control group. The greatest positive effect on soil respiration was observed when GO was used alone, and this effect remained significant even when it was combined with high nano-S. Low nano-S plus a GO dose negatively affected some of the soil respiration types: NAG_SIR, Tre_SIR, Ala_SIR, and Arg_SIR. Single GO application was found to enhance arylsulfatase activity, while the combination of high nano-S and GO not only enhanced arylsulfatase but also urease and phosphatase activity in the soil. The elemental nano-S probably counteracted the GO-mediated effect on organic carbon oxidation. We partially proved the hypothesis that GO-enhanced nano-S oxidation increases phosphatase activity.

Unique forms of manufactured nanomaterials, nanoparticles, and their suspensions are rapidly being created by manipulating properties such as shape, size, structure, and chemical composition and through incorporation of surface coatings. Although these properties make nanomaterial development interesting for new applications, they also challenge the ability of colloid science to understand nanoparticle aggregation in the environment and the subsequent effects on nanomaterial transport and reactivity. This review briefly covers aggregation theory focusing on Derjaguin-Landau-Verwey-Overbeak (DLVO)-based models most commonly used to describe the thermodynamic interactions between two particles in a suspension. A discussion of the challenges to DLVO posed by the properties of nanomaterials follows, along with examples from the literature. Examples from the literature highlighting the importance ofaggregation effects on transport and reactivity and risk of nanoparticles in the environment are discussed.

An Environmental Risk Assessment (ERA) for nanomaterials (NMs) is outlined in this paper. Contrary to other recent papers on the subject, the main data requirements, models and advancement within each of the four risk assessment domains are described, i.e., in the: (i) materials, (ii) release, fate and exposure, (iii) hazard and (iv) risk characterisation domains. The material, which is obviously the foundation for any risk assessment, should be described according to the legislatively required characterisation data. Characterisation data will also be used at various levels within the ERA, e.g., exposure modelling. The release, fate and exposure data and models cover the input for environmental distribution models in order to identify the potential (PES) and relevant exposure scenarios (RES) and, subsequently, the possible release routes, both with regard to which compartment(s) NMs are distributed in line with the factors determining the fate within environmental compartment. The initial outcome in the risk characterisation will be a generic Predicted Environmental Concentration (PEC), but a refined PEC can be obtained by applying specific exposure models for relevant media. The hazard information covers a variety of representative, relevant and reliable organisms and/or functions, relevant for the RES and enabling a hazard characterisation. The initial outcome will be hazard characterisation in test systems allowing estimating a Predicted No-Effect concentration (PNEC), either based on uncertainty factors or on a NM adapted version of the Species Sensitivity Distributions approach. The risk characterisation will either be based on a deterministic risk ratio approach (i.e., PEC/PNEC) or an overlay of probability distributions, i.e., exposure and hazard distributions, using the nano relevant models.

The huge evolution of nanotechnology and the commercialization of nanomaterials (NMs) positively contributed for innovation in several industrial sectors. Facing this rapid development and the emergence of NMs in the market, the release of this nanometric sized materials in the environment and the possible impact on different ecosystem components attracted the attention of researchers in the last few years. In our study we aimed to assess the impact of titanium silicon oxide nanomaterial (nano-TiSiO4) on soil biota to estimate a risk limit for this material. In the present research a battery of standardized ecotoxicological assays aimed at evaluating a wide range of endpoints (avoidance and reproduction of earthworms and collembolans, emergence/growth of four selected terrestrial plants) were carried out, using OECD artificial soil as test substrate spiked with aqueous suspension of different concentrations of nano-TiSiO4. The results showed a maximum avoidance percentage of 40% for earthworms (Esenia andrei) at the highest concentration tested (1000mgkg(-1) soildw of nano-TiSiO4). No significant effect on the reproductive function of both invertebrate species was recorded. Nevertheless, significant phytotoxic data was registered at least for the growth of dicotyledonous plant species (Lactuca sativa and Lycopersicon lycopersicum) with EC20 values ranging between 236 and 414 mg kg(-1) soildw of nano-TiSiO4 for L. sativa dry mass and fresh mass, respectively. Further, the characterization of nano-TiSiO4 in suspensions used to spike the soil, performed by Dynamic Light Scattering, showed the formation of aggregates with important average size diameter, thus demonstrating that the toxic effects observed were likely not size dependent. A deterministic PNEC (predicted no effect concentration) for this NM of 10.02mg kg(-1) soildw of nano-TiSiO4, is suggested, while no more ecotoxicological information exists.Copyright © 2016 Elsevier Inc. All rights reserved.

Phytostimulators are attracting considerable attention for replacing mineral fertilizers, which are of environmental concern, being especially forbidden in organic farming. The benefit of applying such products based on microorganisms (e.g., algae extract) or minerals of nano-meter-sized particle (e.g., nanofertilizers) is that plants can uptake them faster than soil fertilizers, targeting plant growth by regulating their phytohormones, as well as improving plant tolerance to unfavorable environmental conditions (e.g., cold stress). The aim of this study was to test and evaluate the effects of three commercial phytostimulators, called biostimulants (a seaweed-based extract—Kelpak®, mineral nanoparticles—Nano Active®, zinc nanoparticles—Dynamic Cresco®) on yield, chlorophyll content, level of CO2 assimilation and the effectiveness of PSII under cold stress. The values of all chlorophyll fluorescence and photosynthetic parameters significantly decreased under cold, which indicated a strong inhibition of light-phase photosynthesis in maize leaves. Predicted by the regression analysis minimum, 20 days was enough for maize plants to recover from the inhibition caused by stress damages in their photosynthetic apparatus. At the final measurement in maize growth stage BBCH 65, all the tested phytostimulators showed significant effects in increased values of effective quantum yield of photosystem II, maximum photosynthetic efficiency of PSII and electron transport rate. At this stage, Dynamic Cresco® and Nano Active® treatment significantly increased the value of maximum net photosynthetic rate (15.37% and 18.85%, respectively) and leaf chlorophyll content (7.8% and 8.7%, respectively). The application of Dynamic Cresco® significantly promoted total dry weight by 43.4% in comparison to control under stress growth conditions with cold. These phytostimulators can be used to enhance yield and physiological status of plants after abiotic stress (such as cold) to improve crop productivity, especially in organic farming.

Extensive utilization of silver nanoparticles (NPs) in agricultural products results in their interaction with other chemicals in the environment. To study the combined effects of silver NPs with nicotinic acid and potassium nitrate (KNO3), a gel-free/label-free proteomic technique was used. Root length/weight and hypocotyl length/weight of soybean were enhanced by silver NPs mixed with nicotinic acid and KNO3. Out of a total 6340 identified proteins, 351 proteins were significantly changed, out of which 247 and 104 proteins increased and decreased, respectively. Differentially changed proteins were predominantly associated with protein degradation and synthesis according to the functional categorization. Protein-degradation-related proteins mainly consisted of the proteasome degradation pathway. The cell death was significantly higher in the root tips of soybean under the combined treatment compared to flooding stress. Accumulation of calnexin/calreticulin and glycoproteins was significantly increased under flooding with silver NPs, nicotinic acid, and KNO3. Growth of soybean seedlings with silver NPs, nicotinic acid, and KNO3 was improved under flooding stress. These results suggest that the combined mixture of silver NPs, nicotinic acid, and KNO3 causes positive effects on soybean seedling by regulating the protein quality control for the mis-folded proteins in the endoplasmic reticulum. Therefore, it might improve the growth of soybean under flooding stress.