title: Drought-tolerance of wheat improved by rhizosphere bacteria from harsh environments: enhanced biomass production and reduced emissions of stress volatiles.
abstract: Water is the key resource limiting world agricultural production. Although an impressive number of research reports have been published on plant drought tolerance enhancement via genetic modifications during the last few years, progress has been slower than expected. We suggest a feasible alternative strategy by application of rhizospheric bacteria coevolved with plant roots in harsh environments over millions of years, and harboring adaptive traits improving plant fitness under biotic and abiotic stresses. We show the effect of bacterial priming on wheat drought stress tolerance enhancement, resulting in up to 78% greater plant biomass and five-fold higher survivorship under severe drought. We monitored emissions of seven stress-related volatiles from bacterially-primed drought-stressed wheat seedlings, and demonstrated that three of these volatiles are likely promising candidates for a rapid non-invasive technique to assess crop drought stress and its mitigation in early phases of stress development. We conclude that gauging stress by elicited volatiles provides an effectual platform for rapid screening of potent bacterial strains and that priming with isolates of rhizospheric bacteria from harsh environments is a promising, novel way to improve plant water use efficiency. These new advancements importantly contribute towards solving food security issues in changing climates.
authors.affiliation: Dept. of Forest Mycology and Plant Pathology, Uppsala BioCenter, SLU, Uppsala, Sweden.
authors.forename: Salme
authors.initials: S
authors.lastname: Timmusk
authors.affiliation: Dept. of Forest Mycology and Plant Pathology, Uppsala BioCenter, SLU, Uppsala, Sweden.
authors.forename: Islam A
authors.initials: IA
authors.lastname: Abd El-Daim
authors.affiliation: Dept. of Plant Physiology, Estonian University of Life Sciences, Tartu, Estonia.
authors.forename: Lucian
authors.initials: L
authors.lastname: Copolovici
authors.affiliation: Dept. of Plant Physiology, Estonian University of Life Sciences, Tartu, Estonia.
authors.forename: Triin
authors.initials: T
authors.lastname: Tanilas
authors.affiliation: Dept. of Plant Physiology, Estonian University of Life Sciences, Tartu, Estonia.
authors.forename: Astrid
authors.initials: A
authors.lastname: Kännaste
authors.affiliation: Dept. of Forest Mycology and Plant Pathology, Uppsala BioCenter, SLU, Uppsala, Sweden.
authors.forename: Lawrence
authors.initials: L
authors.lastname: Behers
authors.affiliation: Institute of Evolution, The University of Haifa, Haifa, Israel.
authors.forename: Eviatar
authors.initials: E
authors.lastname: Nevo
authors.affiliation: Dept. of Chemistry and Biotechnology, Uppsala BioCenter, SLU, Uppsala, Sweden.
authors.forename: Gulaim
authors.initials: G
authors.lastname: Seisenbaeva
authors.affiliation: Dept. of Forest Mycology and Plant Pathology, Uppsala BioCenter, SLU, Uppsala, Sweden.
authors.forename: Elna
authors.initials: E
authors.lastname: Stenström
authors.affiliation: Dept. of Plant Physiology, Estonian University of Life Sciences, Tartu, Estonia; Estonian Academy of Sciences, Tallinn, Estonia.
authors.forename: Ülo
authors.initials: Ü
authors.lastname: Niinemets
mesh_terms: D018533:Biomass; D055864:Droughts; D004777:Environment; D010641:Phenotype; D018517:Plant Roots / Q000235:genetics; D058441:Rhizosphere; D036226:Seedlings / Q000235:genetics; D013312:Stress, Physiological / Q000235:genetics*; D014908:Triticum / Q000235:genetics*