An auxin secreting Pseudomonas putida rhizobacterial strain that negatively impacts water-stress tolerance in Arabidopsis thaliana

Here we report some novel observations in the interaction between the model plant, Arabidopsis thaliana and a Pseudomonas putida strain of rhizobacteria which was observed to release copious amounts of the auxin, indole acetic acid (IAA) under water-stressed conditions. On inoculation with A. thaliana, this strain exhibited a strong inhibitory effect on water-stress tolerance ability of the plant, while promoting plant growth under well-watered conditions. Plants exposed to water-stress with simultaneous P. putida inoculation exhibited enhanced drying and reduced plant water content as opposed to water-stressed plants without PGPR inoculation. We conclude that in the concentration used in the present study, this strain of P. putida enhances the susceptibility of A. thaliana to water-stress.