Effects of Pseudomonas Fluorescens FY32 On Canola (Brassica Napus L.) Cultivars Under Drought Stress Induced by Polyethylene Glycol

Environmental stresses, such as drought, represent the most limiting factors for agricultural productivity. Drought stress has drastic effects on the growth of canola plants. This study investigates the effects of inoculation with Pseudomonas fluorescens FY32 on the growth and antioxidant status of canola cultivars under drought stress induced by polyethylene glycol (PEG). The results show that bacterial inoculation improves the aerial dry weights and root length of canola plants under moderate drought stress. Peroxidase activity, as an antioxidant enzyme, increased in response to drought stress, whereas catalase activity remained constant, and polyphenol oxidase activity decreased. Compared to non-inoculated plants, inoculated plants showed significantly higher activities of antioxidant enzymes under drought stress. The inoculated canola cultivar Hyola308 exhibited a better protection mechanism against drought stress and was more tolerant than other cultivars exposed to drought stress, possibly due to its increased growth parameters and antioxidant enzyme activities. These results suggest that inoculation with the Pseudomonas fluorescens FY32 strain might alleviate the adverse effects of drought stress and lead to less stress pressure on plants.