Advances in plant growth-promoting rhizobacteria-mediated abiotic stress mitigation mechanisms in vegetable crops

ABSTRACT Plant growth-promoting rhizobacteria (PGPRs) mediate multifunctional roles in plant growth and development. PGPRs increase vegetable tolerance to abiotic stresses and sustain healthy growth by modulating plant hormones, strengthening antioxidant defences, and restructuring the rhizosphere microbiome. Recently, PGPRs have been widely applied to reduce chemical inputs and mitigate greenhouse gas emissions, demonstrating positive progress and economic benefits. Nevertheless, two critical limitations hinder agricultural implementation: (i) low rhizosphere colonization efficiency and (ii) ecological instability. Emerging evidence also suggests potential legacy effects on native ecosystems following intensive inoculation, necessitating systematic risk assessment. This review synthesizes contemporary advances in PGPRs research through three key lenses: (i) novel colonization strategies leveraging chemotaxis optimization and biofilm engineering; (ii) mechanistic insights into stress alleviation (drought, salinity, chilling resistance, and thermotolerance); and (iii) quantification of agroecological impacts, including soil health improvement, yield-quality enhancement and carbon footprint reduction. Finally, the sustainable application of PGPRs in vegetable cultivation systems is promising. This synthesis establishes both fundamental knowledge and practical frameworks to guide future PGPRs applications in climate-smart vegetable production.