An Indigenous Pseudomonas Strain from Maize Rhizosphere Enhances Plant Growth Through Multiple Mechanisms

The excessive use of chemical fertilizers has depleted agricultural soils, necessitating a paradigm shift toward eco-friendly alternatives such as plant-beneficial microbes. However, the integration of plant-beneficial bacteria into global agroecosystems requires strategic and comprehensive analyses, as well as the development of optimally designed bioinocula to maximize their benefits. In this study, twenty-one rhizobacteria isolated from the maize rhizosphere were systematically screened for plant-beneficial traits, including phosphate and zinc solubilization, indole-3-acetic acid (IAA) production, and the synthesis of extracellular hydrolytic enzymes, followed by their evaluation for plant growth promotion. Among all bacterial isolates, Pseudomonas sp. NCR2 displayed the most comprehensive plant growth-promoting traits. In a pot-scale experiment, maize plants inoculated with multifaceted Pseudomonas sp. NCR2 showed significantly increased root growth, chlorophyll, soluble proteins, and phenolic contents as compared to untreated plants. This study underscores the significance of systematic screening of host-adaptive rhizobacteria for developing promising and tailored bioinocula. Furthermore, the results of this study also demonstrate the use of multifunctional biofertilizing inoculum for the systematic decrease of chemical inputs while simultaneously maintaining the crop productivity.