Location: Crop Bioprotection ResearchTitle: Plant-associated bacteria mitigate drought stress in soybean
|MARTINS, SAMUEL - Federal University Of Goias
|ROCHA, GEISIANE - Federal University Of Goias
|DE MELO, HYRANDIR - Federal University Of Goias
|GEORG, RAPHAELA - Federal University Of Goias
|ULHOA, CIRANO - Federal University Of Goias
|DIANESE, ERICO - Federal University Of Goias
|OSHIQUIRI, LETICIA - Federal University Of Goias
|DA CUNHA, MARCOS - Federal University Of Goias
|DA ROCHA, MARA - Federal University Of Goias
|DE ARAUJO, LEILA - Federal University Of Goias
|VAZ, KARINA - Federal University Of Goias
Submitted to: Plant Physiology and Biochemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/23/2018
Publication Date: 5/1/2019
Citation: Martins, S.J., Rocha, G.A., De Melo, H.C., Georg, R.D., Ulhoa, C.J., Dianese, E.C., Oshiquiri, L.H., Da Cunha, M.G., Da Rocha, M.R., De Araujo, L.G., Vaz, K.S., Dunlap, C.A. 2019. Plant-beneficial bacteria mitigate drought stress in soybean. Plant Physiology and Biochemistry. 25:13676–13686. https://doi.org/10.1007/s11356-018-1610-5.
Interpretive Summary: An ARS researcher from Peoria, IL collaborated with scientists from Federal University of Goiás in Goiânia, Brazil to characterize plant beneficial bacteria in soybeans. This manuscript reports on the characterization of a several bacteria strains that were selected on their potential to promote drought tolerance in soybeans. The results show that these strains are capable of enhancing the drought tolerance of soybeans under greenhouse conditions. This research benefits soybean researchers, producers and consumers by identifying bacteria that provide drought tolerance for soybeans.
Technical Abstract: Agriculture accounts for ~70% of all water use and the world population is increasing annually, soon more people will need to be fed, while also using less water. The use of plant-beneficial bacteria (PBB) is an eco-friendly alternative that can increase crop water use efficiency. This work aimed to study the effect of some PBB on increasing soybean tolerance to drought stress, the mechanisms of the drought tolerance process, and the effect of the PBB on promoting plant growth and on the biocontrol of S. sclerotiorum. PBB were isolated from soybean rhizosphere, and Sclerotinia sclerotiorum sclerotia. The strains identified as UFGS1 (Bacillus subtilis), UFGS2 (B. thuringiensis), UFGRB2 and UFGRB3 (B. cereus) were selected on their ability to grow in media with reduced water activity. Soybean plants were inoculated with the PBB and evaluated for growth promotion, physiological and molecular parameters, after drought stress. Under drought stress, UFGS2 and UFGRB2 sustained potential quantum efficiency of PSII (Fv/Fm), while a decrease was found in the control plants. Moreover, UFGS2 and UFGRB3 maintained the photosynthetic rates in normal conditions compared to the control. UFGS2-treated plants showed a higher stomatal conductance and higher transpiration than the control, after drought stress. Some PBB treated strains also had other beneficial phenotypes, such as, increases in fresh and dried biomass relative to the control. Differential gene expression analysis of genes involved in plant stress pathways show changes in expression in PBB treated plants. Results from this study suggest that PBB can mitigate drought stress in soybean and may improve water efficiency under certain conditions.