Effects of plant growth-promoting rhizobacteria on uptake and utilization of phosphorus and root architecture in apple seedlings under water limited regimes

The aim of this research was to examine the relationships among Pseudomonas fluorescens (YX2) plant growth promoting rhizobacteria (PGPR), phosphorus (P) absorption by plants, and root system architecture in apple seedlings exposed to mild, moderate or severe drought stresses. All the treatments were divided into two groups: 1) inoculated with a plant rhizobacterial strain (YX2), and 2) the non-inoculated control. Under drought stress, the YX2 inoculation improved root growth, root activity by 6%, and uptake of P, thereby promoting apple seedling growth along with the dry weight of above-ground plant parts in the mild and moderate water stress regimes. Furthermore, the inoculation also promoted total P contents in plants under both mild and moderate drought stresses. Overall, application of Pseudomonas fluorescens (YX2) is a promising approach to enhance apple production in agricultural production systems.