Nano-fertilizers (NFs) significantly improve soil quality and plant growth performance and enhance crop production with quality fruits/grains. The management of macro-micronutrients is a big task globally, as it relies predominantly on synthetic chemical fertilizers which may not be environmentally friendly for human beings and may be expensive for farmers. NFs may enhance nutrient uptake and plant production by regulating the availability of fertilizers in the rhizosphere; extend stress resistance by improving nutritional capacity; and increase plant defense mechanisms. They may also substitute for synthetic fertilizers for sustainable agriculture, being found more suitable for stimulation of plant development. They are associated with mitigating environmental stresses and enhancing tolerance abilities under adverse atmospheric eco-variables. Recent trends in NFs explored relevant agri-technology to fill the gaps and assure long-term beneficial agriculture strategies to safeguard food security globally. Accordingly, nanoparticles are emerging as a cutting-edge agri-technology for agri-improvement in the near future. Interestingly, they do confer stress resistance capabilities to crop plants. The effective and appropriate mechanisms are revealed in this article to update researchers widely.

Combating climate change and ensuring energy supply to a rapidly growing global population has highlighted the need to replace petroleum fuels with clean, and sustainable renewable fuels. Biofuels offer a solution to safeguard energy security with reduced ecological footprint and process economics. Over the past years, lignocellulosic biomass has become the most preferred raw material for the production of biofuels, such as fuel, alcohol, biodiesel, and biohydrogen. However, the cost-effective conversion of lignocellulose into biofuels remains an unsolved challenge at the industrial scale. Recently, intensive efforts have been made in lignocellulose feedstock and microbial engineering to address this problem. By improving the biological pathways leading to the polysaccharide, lignin, and lipid biosynthesis, limited success has been achieved, and still needs to improve sustainable biofuel production. Impressive success is being achieved by the retouring metabolic pathways of different microbial hosts. Several robust phenotypes, mostly from bacteria and yeast domains, have been successfully constructed with improved substrate spectrum, product yield and sturdiness against hydrolysate toxins. Cyanobacteria is also being explored for metabolic advancement in recent years, however, it also remained underdeveloped to generate commercialized biofuels. The bacterium Escherichia coli and yeast Saccharomyces cerevisiae strains are also being engineered to have cell surfaces displaying hydrolytic enzymes, which holds much promise for near-term scale-up and biorefinery use. Looking forward, future advances to achieve economically feasible production of lignocellulosic-based biofuels with special focus on designing more efficient metabolic pathways coupled with screening, and engineering of novel enzymes. Graphical Abstract

The deposition of salts in soil seems likely to become a significant barrier for plant development and growth. Halophytes that flourish in naturally saline habitats may sustain extreme salt levels by adopting different acclimatory traits. Insight into such acclimatory features can be useful for devising salt-resilient crops and the reclamation of saline soil. Therefore, salinity-induced responses were studied in two halophytes, i.e., Suaeda nudiflora and Suaeda fruticosa, at a high soil salinity level (ECe 65) to explore their possible tolerance mechanisms in their natural habitat. Samples of different tissues were collected from both Suaeda species for the determination of physio-biochemical attributes, i.e., ionic (Na^+, K⁺, Ca²⁺, Cl⁻) content, osmo-protective compounds (proline, soluble sugars, soluble proteins), total phenolic content, and antioxidant components. Heavy metal composition and accumulation in soil and plant samples were also assessed, respectively. Fourier transform infrared spectroscopy (FTIR) analysis was conducted to explore cellular metabolite pools with respect to high salinity. The results showed that both species considerably adjusted the above-mentioned physio-biochemical attributes to resist high salinity, demonstrated by quantitative differences in their above-ground tissues. The FTIR profiles confirmed the plants’ differential responses in terms of variability in lipids, proteins, carbohydrates, and cell wall constituents. The high capacity for Na⁺ and Cl⁻ accumulation and considerable bioaccumulation factor (BAF) values for metals, mainly Fe and Zn, validate the importance of both Suaeda species as phytodesalination plants and their potential use in the phytoremediation of salt- and metal-polluted soils.

Pueraria tuberosa contains a wide range of bioactive compounds, including polyphenols, alkaloids, and phytosterols, which make it valuable to the pharmaceutical and food industries. Elicitor compounds trigger the defense mechanisms in plants and are widely used to increase the yield of bioactive molecules in in vitro cultures. The present study was conducted to evaluate the effects of different concentrations of biotic elicitors such as yeast extract (YE), pectin (PEC), and alginate (ALG) on growth, antioxidant activity, and metabolite accumulation in in vitro propagated shoots of P. tuberosa. The elicitors applied to shoot cultures of P. tuberosa significantly increased biomass (shoot number, fresh weight, and dry weight), and metabolites such as protein, carbohydrates, chlorophyll, total phenol (TP), and total flavonoid (TF) contents, as well as antioxidant activity compared to untreated control. Biomass, TP, and TF contents, as well as antioxidant activity, were most significant in cultures treated with 100 mg/L PEC. In contrast, chlorophyll, protein, and carbohydrate increased most in cultures treated with 200 mg/L ALG. Application of 100 mg/L of PEC led to the accumulation of high amounts of isoflavonoids including puerarin (220.69 μg/g), daidzin (2935.55 μg/g), genistin (5612 μg/g), daidzein (479.81 μg/g), and biochanin-A (111.511 μg/g) as analyzed by high-performance liquid chromatography (HPLC). Total isoflavonoids content of 100 mg/L PEC treated shoots was obtained as 9359.56 μg/g, 1.68-fold higher than in vitro propagated shoots without elicitors (5573.13 μg/g) and 2.77-fold higher than shoots of the mother plant (3380.17 μg/g). The elicitor concentrations were optimized as 200 mg/L YE, 100 mg/L PEC, and 200 mg/L ALG. Overall, this study showed that the application of different biotic elicitors resulted in better growth, antioxidant activity, and accumulation of metabolites in P. tuberosa, which could lead to obtaining phytopharmaceutical advantages in the future.