Interactive effects of Pseudomonas putida and salicylic acid for mitigating drought tolerance in canola (Brassica napus L.)

This research was designed to analyze the interactive effects of Pseudomonas putida and salicylic acid on the growth of canola in stress and non-stress conditions. Salicylic acid is a phenolic derivative, that has a direct involvement in various plant stages like growth, and inflorescence. While Pseudomonas putida is a drought-tolerant strain having plant growth-promoting characteristics like phosphate solubilization, indole acetic acid, and catalase production. Combined application of Pseudomonas putida and salicylic acid has the ability to develop stress tolerance in plants and also improve growth of plants. They have significant (p < 0.05) effects on germination and morphological, physiological, and biochemical parameters. The plants that received the coapplication of Pseudomonas putida and salicylic acid gave more significant results than their alone application. They showed enhanced germination percentage, germination index, promptness index and, seedling vigor index by 19%, 18%, 34% and, 27%, respectively. There was a substantial increase of 25%, 27%, and 39% in shoot length, root length, and leaf area, respectively. The synergistic effect of both treatments has caused a 14% and 12% increase in the Canola plants' relative water content and membrane stability index respectively. A substantial increase of 18% in proline content was observed by the inoculation of Pseudomonas putida, whereas proline content was increased by 28% by the exogenous application of salicylic acid. The content of flavonoids (39%) and phenol (40%) was significantly increased by the co-application. The increase in superoxide dismutase (46%), ascorbate peroxidase (43%), and glutathione (19%) were also significant. The present research demonstrated that the combined application of Pseudomonas putida and salicylic acid induces drought tolerance in canola and significantly improves its growth.