Characterization of the responses of soil micro-organisms to azoxystrobin and the residue dynamics of azoxystrobin in wheat-corn rotation fields over two years

Bensulfuron methyl induced multiple stress responses in the field wheat plants: Microbial community and metabolic network disturbance

Sulfonylurea (SU) herbicides are widely used and often detected in environmental matrices and have toxic effects on ecosystems and plant development. However, the interaction between SU and soil-plant metabolism during the whole wheat growth cycle remains poorly investigated. Field trials demonstrated that bensulfuron methyl exposure reduced wheat height and a thousand grains' weight, disrupting the critical metabolic pathways, including linoleic acid and amino acid metabolism in the maturity stage. During different growth processes, bensulfuron methyl exposure decreases wheat soil and plants' defense-related indole alkaloid compounds, such as benzoxazinoids and melatonin. Microbial sequencing results showed that bensulfuron methyl treated decreased the abundance of beneficial microorganisms (Gammaproteobacteria, Bacteroidia, and Blastocatella) in the rhizosphere soil, which positively correlated with the inhibition of soil enzyme activity and the secretion of allelopathic substances (benzoxazinoids and melatonin). Molecular docking further confirmed that bensulfuron methyl affects protein molecular structure by establishing hydrogen bonds, which disequilibrate wheat benzoxazinoids and melatonin metabolism. Therefore, bensulfuron methyl exposure disrupted the interaction between soil microorganisms and indole alkaloid metabolism, hindering plant development. This study provides constructive insights into the environmental risks of herbicides and agricultural product safety throughout wheat development.

Carvacrol Encapsulation in Chitosan-Carboxymethylcellulose-Alginate Nanocarriers for Postharvest Tomato Protection

Advancements in polymer science and nanotechnology hold significant potential for addressing the increasing demands of food security, by enhancing the shelf life, barrier properties, and nutritional quality of harvested fruits and vegetables. In this context, biopolymer-based delivery systems present themselves as a promising strategy for encapsulating bioactive compounds, improving their absorption, stability, and functionality. This study provides an exploration of the synthesis, characterization, and postharvest protection applications of nanocarriers formed through the complexation of chitosan oligomers, carboxymethylcellulose, and alginate in a 2:2:1 molar ratio. This complexation process was facilitated by methacrylic anhydride and sodium tripolyphosphate as cross-linking agents. Characterization techniques employed include transmission electron microscopy, energy-dispersive X-ray spectroscopy, infrared spectroscopy, thermal analysis, and X-ray powder diffraction. The resulting hollow nanospheres, characterized by a monodisperse distribution and a mean diameter of 114 nm, exhibited efficient encapsulation of carvacrol, with a loading capacity of approximately 20%. Their suitability for phytopathogen control was assessed in vitro against three phytopathogens-Botrytis cinerea, Penicillium expansum, and Colletotrichum coccodes-revealing minimum inhibitory concentrations ranging from 23.3 to 31.3 μg·mL-1. This indicates a higher activity compared to non-encapsulated conventional fungicides. In ex situ tests for tomato (cv. 'Daniela') protection, higher doses (50-100 μg·mL-1, depending on the pathogen) were necessary to achieve high protection. Nevertheless, these doses remained practical for real-world applicability. The advantages of safety, coupled with the potential for a multi-target mode of action, further enhance the appeal of these nanocarriers.