Among the abiotic stresses, water stress is a key factor that limits agricultural productivity worldwide by reducing crop yield through numerous biochemical and physiological disruptions. The use of nanomaterials in commercially available products is rapidly expanding, with significant applications in agriculture and phytoremediation. Current advancements in nanotechnology have introduced iron nanoparticles (Fe-NPs) as a promising approach to enhance crop resilience against stress conditions. Iron (Fe) plays a critical role in photosynthesis, enzyme activation, chlorophyll synthesis, and oxidative stress management, which are pivotal to plant response against water stress. Due to high surface area, small size, and controlled reactivity, Fe-NPs exhibit exceptional advantages over traditional Fe sources, viz., improved bioavailability and nutrient uptake. The current review explores Fe-NP's potential to mitigate the adverse effects of water stress in crop plants by activating various beneficial mechanisms, including improvement in antioxidant defence, osmotic adjustment, and modulating stress related to phytohormones. Particularly, Fe-NPs improve water use efficiency (WUE) and root development, facilitating water and nutrient uptake under stress conditions. Moreover, Fe-NPs assist in antioxidant enzyme regulation, which reduces the accumulation of reactive oxygen species (ROS), thereby reducing oxidative damage and sustaining the metabolic activities of plants under limited water availability. However, FeNP use in agriculture poses potential health and environmental risks, including water and soil contamination, soil microbial alteration, and residues in edible crop plants, which require careful consideration. Furthermore, Fe-NP effectiveness may vary depending on factors, viz., size of nanoparticles (NPs), concentration, method of application, and crop type. The paper concludes by discussing potential research avenues, highlighting the necessity of sustainable application methods, optimal Fe-NP formulations, and thorough environmental effect evaluations. Fe-NPs are a promising element in creating next-generation, nano-enabled farming techniques meant to increase crop resistance to water stress, which could ultimately improve food security in the face of a changing climate.

Plant pathogens pose a high risk of yield losses and threaten food security. Technological and scientific advances have improved our understanding of the molecular processes underlying host-pathogen interactions, which paves the way for new strategies in crop disease management beyond the limits of conventional breeding. Cross-family transfer of immune receptor genes is one such strategy that takes advantage of common plant immune signalling pathways to improve disease resistance in crops. Sensing of microbe- or host damage-associated molecular patterns (MAMPs/DAMPs) by plasma membrane-resident pattern recognition receptors (PRR) activates pattern-triggered immunity (PTI) and restricts the spread of a broad spectrum of pathogens in the host plant. In the model plant Arabidopsis thaliana, the S-domain receptor-like kinase LIPOOLIGOSACCHARIDE-SPECIFIC REDUCED ELICITATION (AtLORE, SD1-29) functions as a PRR, which senses medium-chain-length 3-hydroxylated fatty acids (mc-3-OH-FAs), such as 3-OH-C10:0, and 3-hydroxyalkanoates (HAAs) of microbial origin to activate PTI. In this study, we show that ectopic expression of the Brassicaceae-specific PRR AtLORE in the solanaceous crop species Solanum lycopersicum leads to the gain of 3-OH-C10:0 immune sensing without altering plant development. AtLORE-transgenic tomato shows enhanced resistance against Pseudomonas syringae pv. tomato DC3000 and Alternaria solani NL03003. Applying 3-OH-C10:0 to the soil before infection induces resistance against the oomycete pathogen Phytophthora infestans Pi100 and further enhances resistance to A. solani NL03003. Our study proposes a potential application of AtLORE-transgenic crop plants and mc-3-OH-FAs as resistance-inducing biostimulants in disease management.