Interactions Between Brassicae napus and Pseudomonas putida (Strain ATCC12633) and Characterization of Volatile Organic Compounds Produced by the Bacterium.

Brassica napus L. is a main oilseed crop cultivated around the world. Plant growth-promoting rhizobacteria (PGPR) are generally applied to a wide range of agricultural crops for the growth enhancement. In this study, an I-plate technique was used to investigate the plant growth-promoting activity of Pseudomonas putida (strain ATCC12633) on B. napus plants. The volatile organic compounds (VOCs) produced by P. putida were determined by gas chromatography-mass spectrometric (GC-MS) analysis. Furthermore, P. putida were evaluated for its efficacy to induce resistance-related enzymes like peroxidase (POD), phenylalanine ammonia-lyase (PAL), catalase (CAT), and other biochemical compounds such as proline (Pro) and hydrogen peroxide (HO) in B. napus plants. According to the results, P. putida significantly increased the growth of B. napus compared to control. The major VOCs released by P. putida were 2-Butynedioic acid, dimethyl ester, Dimethyl ester of 4,7-dimethylnaphthalene-1,2-dicarboxylic acid, N-[3-Methylaminopropyl]aziridine, Cyclododecane, and Hexadecanoic acid. B. napus seeds treatment with P. putida caused enhanced activities of POD, PAL, CAT, Pro, and HO compared to control. So, the results of the present study showed that inoculation of B. napus with P. putida could serve as a useful tool for promoting the plant growth and inducing systemic resistance.