In this work, we report the synthesis of fragmented lignin (FL) assisted zinc oxide (ZnO) and titanium oxide (TiO₂) nanocomposites. The fragmented lignin synthesized from biomass (sugarcane bagasse) was used as a template to generate the morphology and crystallite structure of metal oxide nanomaterial. The nanocomposites were synthesized by a simple precipitation method, wherein fragmented lignin is used in alkaline medium as a template. X-ray diffraction (XRD) analysis shows the phase formation of hexagonal wurtzite ZnO and mixed phase formation of TiO₂ as rutile and anatase. The morphology was studied by using field emission scanning electron microscopy (FE-SEM) and high-resolution transmission electron microscopy (HRTEM). The FE-SEM of pristine ZnO nanocomposites showed a cluster of particles whereas FL–ZnO NPs showed self-aligned nanoparticles in the form of rod shaped having average size 30–70 nm. Pristine TiO₂ nanoparticles showed clusters of particles and FL–TiO₂ nanocomposites showed well crystalline 41nm size nanocomposites. The FL acts as a surfactant which restrict the cluster formations. The band gap determined by diffuse reflectance spectra is 3.10 eV and 3.20 eV for FL–ZnO and FL–TiO₂ nanocomposites, respectively. Photoluminescence spectra of both nanocomposites showed structural defects in the visible region. Further, the antimicrobial activity of pristine ZnO and TiO₂ nanoparticles, and FL–ZnO and FL–TiO₂ nanocomposites against Escherichia coli (ATCC25922), Staphylococcus aureus (ATCC25923) were studied under UV-A (315-400 nm) (8W) for 30min.

Soil salinity is a significant environmental stress that limits plant growth and reduces crop productivity. This problem diminishes the quantity of cultivable land and has a detrimental impact on productivity. Salinity and toxic contaminants, such as heavy metals originating from industrial effluents, are widespread in agricultural lands located in arid and semiarid regions, resulting in low crop productivity. Nevertheless, due to the increasing worldwide population, it is imperative to exploit salt-affected regions for farming to satisfy the demand for food. Certain plants or cultivars have distinct adaptive characteristics that enable them to overcome the adverse effects of elevated salinity and industrial effluents. Phytoremediation is an environmentally friendly and cost-effective approach for restoring heavy metal-contaminated and saline soils. This method utilizes plants to remove or neutralize salts and pollutants, contributing to soil desalination and purification. Enhancing the efficiency of phytoremediation requires a deeper understanding of the mechanisms behind heavy metal accumulation and plant tolerance. Halophytes, which thrive in high-salinity environments, are particularly well-suited for this purpose. Their associated microbes play a crucial role in enhancing salt tolerance and stabilizing toxic substances. This review provides a comprehensive overview of the ability of halophytes to survive in saline conditions and their interactions with soil microorganisms in mitigating soil salinity and industrial pollutants. Addressing these challenges is essential for promoting sustainable agriculture and global food security. Graphical Abstract

Reactive Oxygen Species (ROS) mediated immune response in tomato (Solanum lycopersicum) plants inoculated with arbuscular mycorrhizal fungi (AMF) Glomus fasciculatum (GF) was studied in the presence of plant pathogenic fungi Fusarium oxysporum f. sp. lycopersici (FOL). Our aim was to assess how symbiosis of AMF potentiates ROS immune response system to deal pathogen mediated biotic stress. Tomato plant was inoculated with GF, FOL and GF + FOL in separate experimental sets to examine its effect on plants ROS machinery and the time taken to alleviate biotic stress. The antioxidant response was evaluated and correlated with the time provided by GF treated plants against FOL to initiate their second line of defenses as compared to only FOL treated ones. The establishment of symbiosis and development showed a positive effect on plant ROS response system and subsequently its growth. No significant difference was seen in the root mass of only GF, FOL and GF + FOL. The increase in activities of superoxide dismutase, catalase and peroxidase was similar in all the control and treated plants however; reduction in activities of these ROS scavengers was much faster in GF supplemented plants. Similar trend was also observed for ROS radicals possibly due to the involvement of antioxidant enzymes. LC-MS analysis of FOL was performed to co-relate the effect of some dominant compounds with its pathogenicity. Therefore, our results showcase AMF-GF’s ability to alleviate the oxidative damage generated by biotic stress and highlights on the buffer time taken by plants defense machinery to immunize itself at various levels.