MEPS prepress abstract   -  DOI: https://doi.org/10.3354/meps14682

ABSTRACT: Plant growth-promoting rhizobacteria (PGPR) play a crucial role in enhancing plant growth. However, investigations into the presence and function of PGPR in seagrass rhizospheres remain relatively limited. In this study, we isolated 49 strains of PGPR from Zostera marina rhizospheres and assessed their functional attributes. Additionally, we evaluated the adaptability of these candidate strains under varying environmental conditions, such as temperature, salinity, and pH. Out of the 49 analyzed strains, 6 were found to possess the nifH gene; some strains also exhibited the ability to solubilize inorganic phosphorus, with dissolved phosphorus content ranging widely from 14.6 to 393.9 mg l^–1. Eleven strains demonstrated indole-3-acetic acid (IAA) production, with yields spanning from 16.3 to 42.8 mg l^–1. Thirty-two strains produced siderophores, while ammoniated proteins were produced by 21 strains. Notably, 5 PGPR strains (F65, G84, G85, G86, and I109) displayed multiple growth-promoting properties along with strong adaptability to a wide range of physicochemical conditions. This study highlights the potential reservoir of PGPR in eelgrass rhizosphere and provides significant implications for utilizing these bacteria to enhance the success rate of restoring degraded seagrass meadows.