Effects of carbonaceous nanomaterials on soil-grown soybeans under combined heat and insect stresses

Trends and prospects in graphene and its derivatives toxicity research: A bibliometric analysis

The purpose of this paper is to explore the current research status, hot topics, and future prospects in the field of graphene and its derivatives toxicity. In the article, the Web of Science Core Collection database was used as the data source, and the CiteSpace and VOSviewer were used to conduct a visual analysis of the last 10 years of research on graphene and its derivatives toxicity. A total of 8573 articles were included, and we analyzed the literature characteristics of the research results in the field of graphene and its derivatives toxicity, as well as the distribution of authors and co-cited authors; the distribution of countries and institutions; the situation of co-cited references; and the distribution of journals and categories. The most prolific countries, institutions, journals, and authors are China, the Chinese Academy of Sciences, RSC Advances, and Wang, Dayong, respectively. The co-cited author with the most citations was Akhavan, Omid. The five research hotspot keywords in the field of graphene and its derivatives toxicity were "nanomaterials," "exposure," "biocompatibility," "adsorption," and "detection." Frontier topics were "facile synthesis," "antibacterial activity," and "carbon dots." Our study provides perspectives for the study of graphene and its derivatives toxicity and yields valuable information and suggestions for the development of graphene and its derivatives toxicity research in the future.

The physio-chemical properties and applications of 2D nanomaterials in agricultural and environmental sustainability

Global hunger and nutritional deficiency demand the advancement of existing and conventional approaches to food production. The application of nanoenabled strategies in agriculture has opened up new avenues for enhancing crop yield and productivity. Recently, two-dimensional (2D) nanomaterials (NMs) have manifested new possibilities for increasing food production and nutrition. Graphene nanosheets, the 2D form of graphene has been exemplary in enhancing the loading capacity of agro-active ingredients, their target-specific delivery, bioavailability, and controlled release with slow degradation, resulting in the increased shelf-life/active time of the agro-active components. Also, the development of novel formulations/composites of MXenes and Transition Metal Dichalcogenides (TMDs) can foster plant growth, metabolism, crop production, protection and improvement of soil quality. Additionally, the 2D NM-based biosensors can monitor the nutrient levels and other parameters affecting agronomical traits in plants. This review provides an insight into the details of 2D NM synthesis and functionalization methods. Notably, the review highlights the broad-range of 2D NM applications and their suitability in the development of nanotechnology-based agriformulations. The 2D NM-based derivatives have shown immense potential in enhancing the pedologic parameters, crop productivity, pest-protection and nutritional value. Thus, assisting in achieving food and environmental sustainability goals.

Effect of Graphene Oxide on Growth of Wheat Seedlings: Insights from Oxidative Stress and Physiological Flux

In this study, the responses of wheat seedlings to graphene oxide (GO) were investigated at a wide concentration range of 0-1000 mg L^-1, including oxidative stress, real-time membrane potential as well as proton and calcium ion fluxes. The results show that GO induced a hormesis effect on root growth (low concentration (100 mg L^-1) promotion and high concentration (1000 mg L^-1) inhibition. Oxidative stress was responsible for the growth inhibition at GO concentration of 1000 mg L^-1, as suggested from great stimulation in the activities of antioxidant enzymes and MDA content in roots or leaves. Superoxide dismutase (SOD), catalase (CAT), peroxidase (POD) activities were highly correlated with MDA levels (r² = 0.963, 0.984, and 0.960, respectively). GO exposure caused significant concentration-dependent membrane depolarization in roots, and significantly inhibited H⁺ efflux and extracellular Ca²⁺ influx in root cap.

Soybeans Grown with Carbonaceous Nanomaterials Maintain Nitrogen Stoichiometry by Assimilating Soil Nitrogen to Offset Impaired Dinitrogen Fixation

Engineered nanomaterials (ENMs) can enter agroecosystems because of their widespread use and disposal. Within soil, ENMs may affect legumes and their dinitrogen (N2) fixation, which are critical for food supply and N-cycling. Prior research focusing on end point treatment effects has reported that N2-fixing symbioses in an important food legume, soybean, can be impaired by ENMs. Yet, it remains unknown how ENMs can influence the actual amounts of N2 fixed and what plant total N contents are since plants can also acquire N from the soil. We determined the effects of one already widespread and two rapidly expanding carbonaceous nanomaterials (CNMs: carbon black, multiwalled carbon nanotubes, and graphene; each at three concentrations) on the N economy of soil-grown soybeans. Unlike previous studies, this research focused on processes and interactions within a plant-soil-microbial system. We found that total plant N accumulation was unaffected by CNMs. However, as shown by 15N isotope analyses, CNMs significantly diminished soybean N2 fixation (by 31-78%). Plants maintained N stoichiometry by assimilating compensatory N from the soil, accompanied by increased net soil N mineralization. Our findings suggest that CNMs could undermine the role of legume N2 fixation in supplying N to agroecosystems. Maintaining productivity in leguminous agriculture experiencing such effects would require more fossil-fuel-intensive N fertilizer and increase associated economic and environmental costs. This work highlights the value of a process-based analysis of a plant-soil-microbial system for assessing how ENMs in soil can affect legume N2 fixation and N-cycling.