Unprecedented Synergistic Effects of Nanoscale Nutrients on Growth, Productivity of Sweet Sorghum [Sorghum bicolor (L.) Moench], and Nutrient Biofortification

Merging the occurrence possibility into gene co-expression network deciphers the importance of exogenous 2-oxoglutarate in improving the growth of rice seedlings under thiocyanate stress

Thiocyanate (SCN^-) can find its way into cultivated fields, which might hamper the harmony in carbon and nitrogen metabolism (CNM) of plants, ebbing their quality and productivity. In the current study, we investigated the role of the exogenous application of 2-oxoglutarate (2-OG) in maintaining homeostasis of CNM in rice seedlings under SCN^- stress. Results showed that SCN^- exposure significantly repressed the gene expression and activities of CNM-related enzymes (e.g., phosphoenolpyruvate carboxylase, NADP-dependent isocitrate dehydrogenases, and isocitrate dehydrogenases) in rice seedlings, thereby reducing their relative growth rate (RGR). Exogenous application of 2-OG effectively mitigated the toxic effects of SCN^- on rice seedlings, judged by the aforementioned parameters. The co-expression network analysis showed that genes activated in CNM pathways were categorized into four modules (Modules 1-4). In order to identify the key module activated in CNM in rice seedlings exposed to SCN^-, the results from real-time quantitative PCR (RT-qPCR) tests were used to calculate the possibility of the occurrence of genes grouped in four different modules. Notably, Module 3 showed the highest occurrence probability, which is mainly related to N metabolism and 2-OG synthesis. We can conclude that exogenous application of 2-OG can modify the imbalance of CNM caused by SCN^- exposure through regulating N metabolism and 2-OG synthesis in rice seedlings.

Cow dung extract mediated green synthesis of zinc oxide nanoparticles for agricultural applications

In the present study, zinc oxide nanoparticles (ZnO) were synthesized using cow dung extract to apply sustainable agriculture from rural resources. Studies on their antibacterial potential against E. coli DH 5 alpha indicated lower antimicrobial activities than the bulk Zn and commercial Zn nanoparticles. Compared with control and commercial ZnO nanoparticles, the maximum seed germination, root length, and shoot length were observed after the priming of synthesized ZnO NPs. This study suggests that ZnO may significantly increase seed germination and have lower antimicrobial potential. Further, the lower in-vitro cellular leakage and reactive oxygen species (ROS) production provided new hope for using cow dung extract mediated nanoparticles for agricultural and industrial applications.

Physiological responses of pumpkin to zinc oxide quantum dots and nanoparticles

The present study investigated that the potential of soil or foliar applied 15 mg/L zinc oxide quantum dots (ZnO QD, 11.7 nm) to enhance pumpkin (Cucurbita moschata Duch.) growth and biomass in comparison with the equivalent concentrations of other sizes of ZnO particles, ZnO nanoparticles (ZnO NPs, 43.3 nm) and ZnO bulk particles (ZnO BPs, 496.7 nm). In addition, ZnSO4 was used to set a Zn²⁺ ionic control. For foliar exposure, ZnO QD increased dry mass by 56% relative to the controls and values were 17.3% greater than that of the ZnO NPs particles. The cumulative water loss in the ZnO QD treatment was 10% greater than with ZnO NPs, suggesting that QD could better enhance pumpkin growth. For the root exposure, biomass and accumulative water loss equivalent across all Zn treatments. No adverse effects in terms of pigment (chlorophyll and anthocyanin) contents were evident across all Zn types regardless exposure routes. Foliar exposure to ZnO QD caused 40% increases in shoot Zn content as compared to the control; the highest Zn content was evident in the Zn²⁺ ionic treatment, although this did not lead to growth enhancement. In addition, the shoot and root content of other macro- and micro-nutrients were largely equivalent across all the treatments. The contents of other nutritional compounds, including amino acids, total protein and sugar, were also significantly increased by foliar exposure of ZnO QD. The total protein in the ZnO QD was 53% higher than the ZnO particle treatments in the root exposure group. Taken together, our findings suggest that ZnO QDs have significant potential as a novel and sustainable nano-enabled agrichemical and strategies should be developed to optimize benefit conferred to amended crops.

Biogenic preparation of ZnO, CaO, and ZnO-CaO nanocomposites and its influence on agro-morphological characteristics of mung bean

In this study, nanomaterials (ZnO and CaO) and ZnO-CaO nanocomposites (Zn₂₅Ca₇₅O; Zn₅₀Ca₅₀O; Zn₇₅Ca₂₅O) were prepared using co-precipitation method and physico-chemically characterized by XRD, FT-IR, and SEM with EDAX analysis. The XRD pattern of ZnO nanomaterials exhibits hexagonal wurtzite structure and CaO nanomaterials exhibit face-centered cubic (FCC) structure whereas nanocomposites (Zn₇₅Ca₂₅O, Zn₅₀Ca₅₀O, Zn₂₅Ca₇₅O) exhibit both hexagonal phase of ZnO and cubic phase of CaO. The SEM images of ZnO-CaO nanocomposites show the well-distributed clusters composed of ZnO and CaO nanoparticles with most of the particles are spherical and some of the particles are rod- and cubic-like morphology. Furthermore, nanomaterials and nanocomposites were used as nano-seed priming agents to assess the seed germination and seedling growth parameters of mung beans. Among the nano-seed priming agents, 500 ppm concentration of the nanocomposite (Zn₅₀Ca₅₀O) showed significant enhancement of germination (100%) and shoot length (11.7 cm), root length (8.9 cm), and vigor index (1910) than other nanomaterials and nanocomposites.

Effects of Soil pH and Coatings on the Efficacy of Polymer coated ZnO Nanoparticulate fertilizers in Wheat (Triticum aestivum)

This study used ZnO nanoparticles (NPs) as seed treatments and as soil amendments to enhance Zn concentrations in wheat grain. In the seed treatment experiment, seeds were treated with dextran coated (DEX-ZnO) and bare ZnO NP suspensions, in addition to ZnSO₄, at 500 mg Zn/L. In the soil amendment experiment, soil pH was adjusted to 6 and 8, then soils were spiked with 15 mg Zn/kg soil in the form of DEX-ZnO and bare ZnO NPs, as well as ZnSO₄. For the seed treatment, ZnO NPs resulted in significantly higher grain Zn concentration 96.9 ± 25.4 compared to (72.2 ± 25.4), (78.3 ± 24.3), and (81.0 ± 19.4) mg Zn/kg in the control, ZnSO₄, and DEX-ZnO NPs treatments, respectively. In the soil amendment experiment, grain Zn concentrations were the same across all Zn treatments regardless of soil pH. Plants grown at pH 6 had higher Zn accumulation and leaf and stem biomass compared to pH 8. This study demonstrates that treatment of seeds with ZnO NPs can enhance Zn content of grain using far less Zn than is typically used for soil amendments. This may help reduce the environmental impact of Zn fertilization.

The Combination of Simultaneous Plasma Treatment with Mg Nanoparticles Deposition Technique for Better Mung Bean Seeds Germination

A novel method based on the combination of simultaneous cold plasma treatment with Mg nanoparticles deposition, applied to Mung bean seeds by improving their quality, is presented. The SRIM simulation reveals that only the very top layer of the seeds surface can be altered by the plasma. The experimental analysis indicates surface composition changes with a polar groups formation. These groups initiate the shift of surface characteristics from hydrophobic to hydrophilic. The chemical bond analysis shows the formation of MgO and Mg(OH)2 compounds, which acts as a positive factor for seeds germination and growth. The germination experiments showed a 70% outcome with an average of 73.9 mm sprouts length after 30 min of plasma treatment compared to the initial seeds (40% outcome and 71.3 mm sprouts length).

Guiding the design space for nanotechnology to advance sustainable crop production

The globally recognized need to advance more sustainable agriculture and food systems has motivated the emergence of transdisciplinary solutions, which include methodologies that utilize the properties of materials at the nanoscale to address extensive and inefficient resource use. Despite the promising prospects of these nanoscale materials, the potential for large-scale applications directly to the environment and to crops necessitates precautionary measures to avoid unintended consequences. Further, the effects of using engineered nanomaterials (ENMs) in agricultural practices cascade throughout their life cycle and include effects from upstream-embodied resources and emissions from ENM production as well as their potential downstream environmental implications. Building on decades-long research in ENM synthesis, biological and environmental interactions, fate, transport and transformation, there is the opportunity to inform the sustainable design of nano-enabled agrochemicals. Here we perform a screening-level analysis that considers the system-wide benefits and costs for opportunities in which ENMs can advance the sustainability of crop-based agriculture. These include their on-farm use as (1) soil amendments to offset nitrogen fertilizer inputs, (2) seed coatings to increase germination rates and (3) foliar sprays to enhance yields. In each analysis, the nano-enabled alternatives are compared against the current practice on the basis of performance and embodied energy. In addition to identifying the ENM compositions and application approaches with the greatest potential to sustainably advance crop production, we present a holistic, prospective, systems-based approach that promotes emerging alternatives that have net performance and environmental benefits.

Nano-micronutrients [γ-Fe2O3 (iron) and ZnO (zinc)]: green preparation, characterization, agro-morphological characteristics and crop productivity studies in two crops (rice and maize)

Nanotechnology based fertilizer production possessing the desired chemical composition, can improve plant nutrition and may reduce the environmental impact and enhance the plant productivity.

Local fertilizers to achieve food self-sufficiency in Africa

One of the key Sustainable Development Goals (SDG) set by the United Nations (UN) aims by 2030 to "end hunger, achieve food security and improved nutrition and promote sustainable agriculture". Fertilizers will play a pivotal role in achieving that goal given that ~90% of crop production growth is expected to come from higher yields and increased cropping intensity. However, materials-science research on fertilizers has received little attention, especially in Africa. In this work we present an overview of the use of fertilizers in Africa to date, and based on that overview we suggest future research directions for material scientists. Developing a new generation of local and affordable fertilizers will launch Africa into a new phase of remunerative agricultural production that in turn will lead to both food self-sufficiency and considerable progress towards goals of food and nutrition security.

Functionalized-ZnO-Nanoparticle Seed Treatments to Enhance Growth and Zn Content of Wheat ( Triticum aestivum) Seedlings

This study investigated the potential of ZnO-nanoparticle (NP) seed treatments for enhancing Zn nutrition in wheat ( Triticum aestivum). We tested bare, ZnO core Zn₃(PO₄)₂ shell, dextran (DEX)-coated, and dextran sulfate (DEX(SO₄))-coated ZnO NPs and ZnSO₄ solution as an ionic control. We measured root and shoot Zn concentrations, lengths, biomasses, and seed germination upon termination of the assay. All ZnO NPs were more effective than ZnSO₄ in increasing tissue Zn concentrations and seedling growth. Exposure to higher concentrations of ZnSO₄ significantly decreased growth and germination rates relative to those of the controls and the ZnO-NP groups, whereas none of the ZnO NPs significantly affected seed germination. Bare and DEX-ZnO NPs increased Zn concentrations in wheat without decreasing growth. The results of this study demonstrated that ZnO NPs can be used as an effective seed treatment to enhance both Zn nutrition and plant growth.