This review article explores the impact of nitrogen fertilizers on the symbiotic relationship between Rhizobium bacteria and legume plants. Nitrogen fixation has the potential to address the global protein shortage by increasing nitrogen supply in agriculture. However, the excessive use of synthetic fertilizers has led to environmental consequences and high energy consumption. To promote sustainable agriculture, alternative approaches such as biofertilizers that utilize biological nitrogen fixation have been introduced to minimize ecological impact. Understanding the process of biological nitrogen fixation, where certain bacteria convert atmospheric nitrogen into ammonia, is crucial for sustainable agriculture. This knowledge helps reduce reliance on synthetic fertilizers and maintain soil fertility. The symbiotic relationship between Rhizobium bacteria and leguminous plants plays a vital role in sustainable agriculture by facilitating access to atmospheric nitrogen, improving soil fertility, and reducing the need for chemical fertilizers. To achieve optimal nitrogen fixation and plant growth, it is important to effectively manage nitrogen availability, soil conditions, and environmental stressors. Excessive nitrogen fertilization can negatively affect the symbiotic association between plants and rhizobia, resulting in reduced soil health, altered mutualistic relationships, and environmental concerns. Various techniques can be employed to enhance symbiotic efficiency by manipulating chemotaxis, which is the ability of rhizobia to move towards plant roots. Plant-specific metabolites called (iso)flavonoids play a crucial role in signaling and communication between legume plants and rhizobia bacteria, initiating the symbiotic relationship and enhancing nitrogen fixation and plant growth. Excessive nitrogen fertilizer application can disrupt the communication between rhizobia and legumes, impacting chemotaxis, root exudation patterns, nodulation, and the symbiotic relationship. High levels of nitrogen fertilizers can inhibit nitrogenase, a critical enzyme for plant growth, leading to reduced nitrogenase activity. Additionally, excessive nitrogen can compromise the energy demands of nitrogen fixation, resulting in decreased nitrogenase activity. This review discusses the disadvantages of using nitrogenous fertilizers and the role of symbiotic biological nitrogen fixation in reducing the need for these fertilizers. By using effective rhizobial strains with compatible legume cultivars, not only can the amounts of nitrogenous fertilizers be reduced, but also the energy inputs and greenhouse gas emissions associated with their manufacturing and application. This approach offers benefits in terms of reducing greenhouse gas emissions and saving energy. In conclusion, this paper provides a comprehensive overview of the current understanding of the impact of nitrogen fertilizers on the symbiotic relationship between Rhizobium and legume plants. It also discusses potential strategies for sustainable agricultural practices. By managing nitrogen fertilizers carefully and improving our understanding of the symbiotic relationship, we can contribute to sustainable agriculture and minimize environmental impact.

This study was planned to enhance the growth and productivity of common bean plants (Phaseolus vulgaris L.) grown under different water stress level by using different microorganisms as bio-fertilizer agents. Water stress is a international problem that effects on morphological, functional and chemical processes of plants occasioning in altering growth, yield and water relations of economic plants like common bean plants. The interaction effect between water stress (WW as recommended irrigation after 6 days, WS1 after 12 days and WS2 after 18 days) and inoculation with different microorganisms [AMF (Glomus mosseae) and endophytic bacteria, (Bacillus amyloliquefaciens)] used alone or in mixed was examined on the development and productivity of common bean plants. Mutual application of AMF and endophytic bacteria significantly increased the average values of most of growth, water relations (photosynthetic rate, transpiration rate and stomatal conductance) and yield parameters of common bean plants grown at WS1 and WS2 comparing with non-colonized plants. In this connection, colonization with AMF and endophytic bacteria with WS1 are the greater pods number, pod length, pods weight, 100 seeds weight, Yield by ton /Fed and water-use efficiency (WUE) by ton/ m3 than other treatments. Common bean yielded seeds had significantly increased nutrients content (nitrogen, potassium, phosphorus, magnesium and calcium), vitamin B1, Folic acid, crude protein and crude fibers at AMF + endophytic bacteria under second water stress (WS1) when compared to other treatments.

The effect of organic (poultry and cattle manures) and biological (effective microorganisms, EM) fertilizers on growth, essential oil yield and its compositions, endogenous phytohormones content and antibacterial activity of peppermint plants grown in pot over 12 weeks was studied. Application of organo- and bio-fertilizers greatly affected on growth, essential oil production and other estimated parameters of peppermint plants. Slight stimulation effect was happened due to soil application of organic manures. Soil application of EM alone or in combination with organic fertilizers significantly increased growth, yield and components of essential oils, endogenous hormones of peppermint as compared to other treatments. Using disc diffusion method, the extracted oil of peppermint plants amended with organic and biofertilizers recorded the highest antibacterial activity against tested pathogenic bacteria like Klebsiella pneuumoniae and Staphylococcus aureus.

Cadmium (Cd) contamination severely threaten rice productivity and food security, yet effective and sustainable detoxification strategies remain limited. This study investigates whether combined application of prohydrojasmonate (PDJ) and silicon (Si) can synergistically enhance Cd detoxification in rice. Rice seedlings exposed to Cd stress were treated with PDJ, Si or their combination and evaluated through integrated physiological, biochemical and molecular analyses including metal accumulation, photosynthetic performance, oxidative status, hormonal regulation and gene expression. Compared to individual treatments, PDJ-Si co-treatment significantly reduced Cd translocation to aerial tissues, with maximum root retention restored essential leaf elements (Fe, K, Mn) and enhanced photosynthetic efficiency. While PDJ and Si individually enhanced membrane stability, reduced lipid peroxidation and improved osmotic balance their combined application produced the most pronounced effects. Phytohormone profiling revealed coordinated activation of salicylic acid (SA) and jasmonic acid (JA) pathways with balanced abscisic acid (ABA) modulation. Furthermore, both individual and combine application caused differential expression of genes related to detoxification ( OsABCC1 , OsGSTU5 , OsPCS1 ), metal transporters ( OsHMA2 , OsLCT1 ) and hormone biosynthesis ( OsABA2 , OsEDS1 , OsAOS2 ). Collectively, these findings demonstrate that PDJ and Si application enhance Cd detoxification and stress tolerance in rice providing a promising approach for sustainable rice cultivation in Cd-contaminated soils.

Climate change-driven abiotic stresses threaten global potato production, yet stress-specific adaptive mechanisms remain poorly defined. We demonstrate that heat, drought and salt stresses induce fundamentally distinct physiological and biochemical responses in potato plants. Photosynthetic performance and gas exchange showed stress-specific patterns, with heat stress (HS) maintaining elevated carbon metabolism, drought stress (DS) causing severe photosynthetic suppression and water deficit, while salt stress (SS) exhibited intermediate physiological impairment. Secondary metabolite (SM) profiling revealed a corresponding stress-specific signature, where sesquiterpenes (caryophyllene, copaene, humulene) were dramatically elevated under HS but suppressed under DS (which specifically enhanced 1-hexanol and trans-sesquisabinene hydrate), while SS induced copaene and cis-β-farnesene but reduced caryophyllene. Phytohormone analysis demonstrated differential accumulation patterns across stresses: JA, JA-Ile, SA and ABA were maximally elevated under HS, moderately increased under DS, while SS uniquely maintained basal JA/JA-Ile with enhanced SA and ABA. Pharmacological intervention using hormone biosynthesis inhibitors (DIECA, SHAM, Jarin-1, AIP, ABT, fluridone) and exogenous ABA confirmed stress-specific regulatory networks. These findings establish a stress-specific hormone–metabolite regulatory framework, providing a molecular basis for developing climate-resilient potato genotypes.

Plant productivity and food security are increasingly threatened by abiotic and biotic stresses intensified by climate change. Plant genetic engineering offers powerful solutions to enhance stress resilience; however, conventional transformation approaches remain constrained by limited host range, low precision, tissue culture dependency, and regulatory concerns. In this context, nanotechnology has emerged as a transformative enabling platform for precise, efficient, and species-independent delivery of genetic cargo into plant systems. This review provides a comprehensive overview of recent advances in nano-enabled plant genetic engineering for stress resilience, highlighting the role of diverse nanocarriers, including carbon-based nanomaterials (NMs), metal and metal oxide nanoparticles (NPs), polymer-based nanocarriers, and metal–organic frameworks in delivering DNA, RNA interference constructs, and genome-editing components. These nanoplatforms overcome key biological barriers, protect nucleic acids from degradation, and enable controlled, targeted, and often transgene-free genetic modulation. Beyond delivery, many NMs exhibit intrinsic bioactivity, which can synergistically enhance plant stress tolerance through redox regulation, nutrient supplementation, and activation of stress-responsive pathways. The review also critically discusses regulatory and biosafety challenges associated with nano-enabled delivery systems, emphasizing the need for harmonized frameworks tailored to NMs-specific properties. Finally, future perspectives are outlined, focusing on biodegradable nanocarriers, organelle-specific targeting, and integration with CRISPR-based technologies to advance sustainable, precise, and climate-resilient crop improvement strategies.