Hydrocarbon stress (HS) has been causing decreased plant growth and productivity. Putrescine (Put) and growth promoting microbes are vital for plant growth and development under hydrocarbon stress. Current research work was carried out to evaluate the potential of Bacillus megaterium OSR-3 alone and in combination with Put to alleviate HS in Nicotiana tabacum (L.). The crude petroleum contaminated soil significantly reduced growth attributes of N. tabacum. B. megaterium OSR-3 inoculated plants subjected to HS exhibited improved photosynthetic rate, gas exchange characteristics, poline contents and protein level. Furthermore, bacterial inoculation enhanced the antioxidative activity of superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) in tobacco plants subjected to HS. The HS alleviation in B. megaterium OSR-3 inoculated N. tabacum can be credited to the heightened activity of antioxidative enzymes, reduction in hydrogen peroxide (H₂O₂) and abridged synthesis of malondialdehyde (MDA). The increased synthesis of indole acetic acid (IAA) in HS stressed N. tabacum plants treated with co-application of B. megaterium OSR-3 and Put attenuated toxicity and amplified growth of plants. Additionally, the co-application of B. megaterium OSR-3 and Put also upregulated the activity of antioxidative enzymes and induced augmented level of proline and IAA in plants under HS regimes. Current research provides novel insight into the potential and mechanism of B. megaterium OSR-3 and Put in mitigation of HS in N. tabacum plants.

碳氢化合物胁迫（HS）导致植物生长和生产力下降。腐胺（Put）和促进微生物生长对于碳氢化合物胁迫下的植物生长和发育至关重要。目前正在进行的研究工作是评估巨大芽孢杆菌OSR-3单独使用或与Put联合使用以减轻烟草（HS）中的HS的潜力。原油污染的土壤大大降低了烟草的生长特性。巨大芽孢杆菌接种HS的OSR-3植株显示出更高的光合速率，气体交换特性，脯氨酸含量和蛋白质水平。此外，细菌接种增强了遭受HS的烟草植物中超氧化物歧化酶（SOD），过氧化氢酶（CAT）和抗坏血酸过氧化物酶（APX）的抗氧化活性。接种烟草的巨大芽孢杆菌OSR-3中HS的减轻可归因于抗氧化酶活性的增强，过氧化氢（H ₂ O ₂）的减少和丙二醛（MDA）的合成减少。联合应用巨大芽孢杆菌处理过的HS胁迫烟草（N. tabacum）植物中吲哚乙酸（IAA）的合成增加OSR-3和Put减弱了毒性并增强了植物的生长。此外，在HS体制下，巨大芽孢杆菌OSR-3和Put的共同应用还上调了抗氧化酶的活性，并诱导了脯氨酸和IAA含量的升高。目前的研究为巨大芽孢杆菌OSR-3的潜力和机理提供了新的见解，并减轻了烟草中HS的危害。