Abstract

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.

 抽象的

碳氢化合物胁迫（HS）一直导致植物生长和生产力下降。腐胺 (Put) 和促生长微生物对于碳氢化合物胁迫下的植物生长和发育至关重要。目前的研究工作是评估巨大芽孢杆菌OSR-3 单独使用以及与 Put 联合使用缓解烟草(L.) HS 的潜力。原油污染的土壤显着降低了烟草的生长特性。接种了巨大芽孢杆菌OSR-3 的植物经受 HS 处理后表现出改善的光合速率、气体交换特性、果线含量和蛋白质水平。此外，细菌接种增强了受HS影响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。接种巨大芽孢杆菌OSR-3 的烟草中 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 ) 的减少以及丙二醛 (MDA) 合成的减少。在同时施用巨大芽孢杆菌OSR-3 和 Put 处理的 HS 胁迫的烟草植物中，吲哚乙酸 (IAA) 的合成增加，从而减弱了毒性并促进了植物的生长。此外，巨大芽孢杆菌OSR-3 和 Put 的共同施用还上调了 HS 处理下植物中抗氧化酶的活性，并诱导脯氨酸和 IAA 水平增加。目前的研究为巨大芽孢杆菌OSR-3 和 Put 在缓解烟草植物中 H2S 方面的潜力和机制提供了新的见解。