Plant growth promoting rhizobacteria enhance resilience productivity and quality of high value spice crops

Plant growth-promoting rhizobacteria: dual roles in enhancing nutrition and mitigating climate-related abiotic stresses

This review uniquely integrates the biochemical, physiological, and molecular mechanisms of PGPR in plant nutrition and stress mitigation while critically analyzing contradictory field results and highlighting newly characterized strains and sustainable tools for climate-resilient agriculture.

Harnesting Plant Growth Promoting Rhizobacteria to Improve Soybean Agronomic Performance in Salinity Stressed Soils

Climate change has worsened soil salinity through rising temperatures, sea water intrusion, irregular rainfall patterns, and increased evapotranspiration, making salinity one of the major constraints in soybean cultivation worldwide. Salinity stress inhibits plant growth, disrupts nutrient uptake, reduces photosynthesis, induces oxidative stress, and ultimately decreases crop productivity. In addition, excessive salt accumulation deteriorates soil structure, suppresses beneficial microbial activity, and limits nutrient availability, thereby threatening soil health and sustainable agricultural production. Plant Growth Promoting Rhizobacteria (PGPR) can be utilized as an environmentally friendly alternative approach to enhance plant tolerance to saline conditions while reducing dependence on chemical fertilizers and other external inputs. This review examines the extent to which beneficial rhizobacteria improve soybean growth and productivity under salinity stress conditions. The method employed was a systematic literature review combined with bibliometric analysis based on network visualization using VOSviewer. Literature sources were obtained from Scopus covering the period 2020–2026, with article selection conducted using inclusion and exclusion criteria, resulting in 22 relevant articles. The findings indicate that bacteria such as Bradyrhizobium japonicum, Bacillus subtilis, Pseudomonas fluorescens, Azospirillum brasilense, and several other halotolerant bacteria significantly improve soybean tolerance to salinity stress through phytohormone production, biological nitrogen fixation, phosphate solubilization, regulation of Na⁺/K⁺ ion balance, osmoprotectant accumulation, exopolysaccharide production, and activation of antioxidant defense systems. Furthermore, PGPR substantially contribute to soil health by improving soil aggregation, enhancing microbial biodiversity, stimulating nutrient cycling, increasing soil enzyme activities, and improving nutrient-use efficiency in saline soils. Quantitatively, PGPR application has been reported to increase soybean growth and productivity by approximately 15–45% under saline conditions while reducing salt-induced physiological damage. These findings highlight the strong potential of PGPR as a sustainable long-term strategy for saline land management to restore soil health, strengthen climate resilience, and enhance soybean productivity.

Sustainable Production of Solanaceous Vegetable Crops Under Climate Change: The Role of Nanoparticles in Enhancing Abiotic Stress Adaptation

Climate change represents a major global challenge that threatens agricultural productivity, ecosystem stability, and food security by intensifying abiotic stresses such as drought, salinity, and extreme temperatures. Solanaceous crops, which are economically and nutritionally important worldwide, are highly sensitive to these stresses, leading to oxidative damage, impaired photosynthesis, and reduced yield and quality. Nanotechnology has emerged as a promising approach to mitigate these adverse effects. Due to their unique physicochemical properties, nanoparticles (NPs) enhance nutrient uptake, improve water-use efficiency, and regulate plant metabolic processes. They also activate antioxidant defense systems, reduce reactive oxygen species (ROS), and improve the delivery efficiency of growth regulators and bioactive compounds. This review synthesizes recent literature on abiotic stress responses in solanaceous crops and evaluates the role of nanoparticles as mitigation strategies, focusing on physiological, biochemical, and molecular mechanisms. The scope includes drought, salinity, and temperature stresses, as well as nano-enabled applications such as nano-carriers and nano-sensors. Overall, nanoparticle applications improve plant tolerance by enhancing antioxidant activity, regulating stress-responsive pathways, and improving resource-use efficiency, thereby contributing to increased crop productivity under climate change conditions. However, challenges related to nanoparticle toxicity and environmental risks remain, emphasizing the need for optimized and safe application strategies. These findings highlight the potential of nanotechnology as a sustainable tool to enhance the resilience and productivity of solanaceous crops under changing climatic conditions. This review highlights that nanoparticles can enhance abiotic stress tolerance in solanaceous crops by improving antioxidant activity, photosynthesis, nutrient uptake, and water-use efficiency under adverse environmental conditions. Overall, nanotechnology represents a promising strategy for sustainable crop production under climate change, although further studies are needed to ensure its environmental safety and long-term applicability. This review provides a comprehensive overview of abiotic stress effects on solanaceous crops and highlights the role of nanoparticles as a sustainable tool to enhance plant tolerance, productivity, and resilience under climate change conditions.

Abiotic stress response mechanisms, molecular mitigation, and future strategies in millets

Abiotic stresses, such as drought, salinity, temperature extremes, heavy metals, and pesticide toxicity, severely impact plant growth and productivity, primarily through the accumulation of reactive oxygen species (ROS) and metabolic imbalances. In the era of climate change and declining agricultural sustainability, the development of stress-resilient crops has become essential for ensuring global food and nutritional security. Millets, also known as ‘super grain’ or ‘miracle grain’ due to their nutritional value, are recognized for their inherent resilience and exhibit superior adaptability in arid and semi-arid ecosystems towards these abiotic stresses. It is due to their C4 photosynthetic efficiency, rapid life cycles, and deep root architecture. These cereals deploy integrated morphological, physiological, biochemical, and molecular mechanisms, including antioxidant defense systems, osmolyte accumulation, stress-responsive gene expression, and hormonal regulation to maintain homeostasis under stress. Despite these traits, millet improvement lags behind that of major cereals due to limited breeding efforts and underdeveloped molecular resources. This review focuses on recent advances in stress tolerance mechanisms, highlighting omics-driven insights, microbial and phytohormonal mitigation strategies, and exploring genome editing and modern breeding tools, such as CRISPR/Cas9 and genome-wide association studies (GWAS), for developing climate-resilient millet cultivars suitable for sustainable agriculture and future food security. The article explores the development of climate-resilient millet varieties by integrating molecular innovations into traditional agronomic practices, which will provide future benefits framework for developing new varieties. Overall, the article will deepen understanding of the molecular processes underlying stress responses and provide targeted solutions to enhance stress tolerance in millets.

Application of Biostimulants in Enhancing Growth and Productivity of Horticultural Species

Biostimulants have emerged as an innovative and sustainable approach for enhancing plant growth, productivity, quality, and stress tolerance in horticultural crops. Unlike conventional fertilizers and pesticides, biostimulants stimulate natural physiological and biochemical processes that improve nutrient uptake, root development, photosynthesis, flowering, fruit set, and overall crop performance without directly supplying large quantities of nutrients or controlling pests. Biostimulants include a wide range of natural and biological products such as seaweed extracts, humic and fulvic acids, protein hydrolysates, amino acids, beneficial microorganisms, mycorrhizal fungi, plant growth-promoting rhizobacteria (PGPR), silicon, and microbial inoculants. These substances enhance plant metabolism, increase nutrient-use efficiency, strengthen antioxidant defense systems, improve soil microbial activity, and enhance tolerance to abiotic stresses such as drought, salinity, heat, cold, and nutrient deficiency. Their application has gained increasing attention due to growing concerns regarding excessive chemical fertilizer use, environmental degradation, declining soil fertility, and climate change. Modern technologies, including precision horticulture, Internet of Things (IoT), Artificial Intelligence (AI), remote sensing, and data-driven crop management, further optimize biostimulant application by improving timing and dosage. This paper discusses the types and mechanisms of biostimulants, evaluates their role in improving growth, yield, and quality of horticultural crops, examines their contribution to sustainable agriculture and climate resilience, and explores emerging trends, challenges, and future prospects in biostimulant-based horticultural production systems.

Synergistic effects of rhizobacteria and silicon nanoparticles in alleviating drought-induced stress via improved antioxidant and defense responses in plants