Different capability of native and non-native plant growth-promoting bacteria to improve snap bean tolerance to ozone

Authors: KITTIPORNKULA, PIYATIDA - King Mongkut'S Institute Of Technology Ladkrabang; THIRAVETYANA, PAITIP - King Mongkut'S Institute Of Technology Ladkrabang; DE CARLOC, ANNA - National Research Council - Italy; Burkey, Kent; PAOLETTI, ELENA - National Research Council - Italy

Submitted to: Water, Air, and Soil Pollution
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/23/2021
Publication Date: 7/13/2021
Citation: Kittipornkula, P., Thiravetyana, P., De Carloc, A., Burkey, K.O., Paoletti, E. 2021. Different capability of native and non-native plant growth-promoting bacteria to improve snap bean tolerance to ozone. Water, Air, and Soil Pollution. 232:307. https://doi.org/10.1007/s11270-021-05230-z.
DOI: https://doi.org/10.1007/s11270-021-05230-z

Interpretive Summary: Ground level ozone is formed by the action of sunlight on volatile hydrocarbons and nitrogen oxides produced during combustion of carbon-based fuels. Although frequently considered an urban problem, ozone pollution has much broader impacts because weather systems transport the pollutants into agricultural areas where crops are grown. Ozone is toxic to plants, causing visible injury to foliage and a reduction in the growth and yield of sensitive plants. Chemical or biological treatments that reduce ozone stress would be a valuable tool for protecting sensitive crops against this air pollutant. In this study, an international team of scientists from Thailand, Italy, and USDA-ARS at Raleigh, North Carolina showed that specific strains of plant growth-promoting bacteria protected an ozone-sensitive snap bean cultivar when applied to the roots prior to ozone exposure. The results suggest that manipulation of the soil microbiome may be one approach for protecting crops from ozone stress.

Technical Abstract: 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.