The air pollutant ozone (O₃) is a phytotoxic oxidative stressor, leading to visible foliar injury and plant growth decline. Plant growth-promoting bacteria (PGPB) are emerging as an eco-friendly tool for improving plant growth under stress. In order to test PGPB as a tool for alleviating O₃ stress in plants, an O₃ sensitive genotype (Phaseolus vulgaris L. cv S156) was inoculated with native (rhizobacterial; B1 and B2) and non-native PGPB (Bacillus megaterium and B. amylolequefaciens) and exposed to realistic O₃ exposure (ambient, AA with AOT40 = 0.53 ppm per hour, and twice ambient ozone concentration, 2XAA, AOT40 = 1.84 ppm per hour). The promoting effect was assessed by quantifying visible foliar O₃ injury (PII), chlorophyll a fluorescence (Fv/Fm), contents of hydrogen peroxide (H₂O₂), malondialdehyde (MDA) and nitric oxide (NO), ethylene emission, 1-aminocyclo-propane-1-carboxylate (ACC) deaminase enzyme activity, above- and below-ground biomass. BM, BA and B1 showed higher ACC deaminase enzyme activity and Fv/Fm, while ethylene emission, PII, H₂O₂, MDA and NO contents were lower in the BM, BA and B1 plants than in the B2 and non-inoculated plants under 2XAA. Only BA increased above- and below-ground biomass under AA and 2XAA. We conclude that PGPB are able to ameliorate O₃ stress through induction of systemic resistance; the level of bacterial ACC deaminase is one of the good markers for identifying effective strains and may be tested as an agricultural practice for improving crop yield under O₃ pollution.

空气污染物臭氧 (O ₃ ) 是一种植物毒性氧化应激物，会导致可见的叶面损伤和植物生长下降。植物生长促进细菌 (PGPB) 正在成为一种改善胁迫下植物生长的环保工具。为了测试 PGPB 作为减轻植物中O ₃胁迫的工具，O ₃敏感基因型（菜豆属L. cv S156）接种了天然（根际细菌；B1 和 B2）和非天然 PGPB（巨大芽孢杆菌和B . amylolequefaciens）并暴露于真实的 O ₃暴露（环境，AA，AOT40 = 0.53 ppm/小时，环境臭氧浓度的两倍，2XAA，AOT40 = 1.84 ppm/小时）。通过量化可见的叶面 O ₃损伤 (PII)、叶绿素a荧光 (Fv/Fm)、过氧化氢 (H ₂ O ₂ )、丙二醛 (MDA) 和一氧化氮 (NO) 的含量、乙烯排放、 1-aminocyclo-propane-1-carboxylate (ACC) 脱氨酶活性，地上和地下生物量。BM、BA 和 B1 表现出较高的 ACC 脱氨酶活性和 Fv/Fm，而乙烯排放、PII、H ₂ O ₂在 2XAA 下，BM、BA 和 B1 植物中的 MDA 和 NO 含量低于 B2 和未接种植物。在 AA 和 2XAA 下，只有 BA 增加了地上和地下生物量。我们得出结论，PGPB 能够通过诱导全身抵抗来改善 O ₃压力；细菌ACC脱氨酶的水平是鉴定有效菌株的良好标志之一，可作为在O ₃污染下提高作物产量的农业实践进行测试。