Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Abscisic acid metabolizing rhizobacteria decrease ABA concentrations in planta and alter plant growth
AU - Belimov, Andrey A.
AU - Dodd, Ian C.
AU - Safronova, Vera I.
AU - Dumova, Valentina A.
AU - Shaposhnikov, Alexander I.
AU - Ladatko, Alexander G.
AU - Davies, William J.
N1 - Copyright © 2013 Elsevier Masson SAS. All rights reserved.
PY - 2014/1
Y1 - 2014/1
N2 - Although endogenous phytohormones such as abscisic acid (ABA) regulate root growth, and many rhizobacteria can modulate root phytohormone status, hitherto there have been no reports of rhizobacteria mediating root ABA concentrations and growth by metabolising ABA. Using a selective ABA-supplemented medium, two bacterial strains were isolated from the rhizosphere of rice (Oryza sativa) seedlings grown in sod-podzolic soil and assigned to Rhodococcus sp. P1Y and Novosphingobium sp. P6W using partial 16S rRNA gene sequencing and phenotypic patterns by the GEN III MicroPlate test. Although strain P6W had more rapid growth in ABA-supplemented media than strain P1Y, both could utilize ABA as a sole carbon source in batch culture. When rice seeds were germinated on filter paper in association with bacteria, root ABA concentration was not affected, but shoot ABA concentration of inoculated plants decreased by 14% (strain P6W) and 22% (strain P1Y). When tomato (Solanum lycopersicum) genotypes differing in ABA biosynthesis (ABA deficient mutants flacca - flc, and notabilis - not and the wild-type cv. Ailsa Craig, WT) were grown in gnotobiotic cultures on nutrient solution agar, rhizobacterial inoculation decreased root and/or leaf ABA concentrations, depending on plant and bacteria genotypes. Strain P6W inhibited primary root elongation of all genotypes, but increased leaf biomass of WT plants. In WT plants treated with silver ions that inhibit ethylene perception, both ABA-metabolising strains significantly decreased root ABA concentration, and strain P6W decreased leaf ABA concentration. Since these changes in ABA status also occurred in plants that were not treated with silver, it suggests that ethylene was probably not involved in regulating bacteria-mediated changes in ABA concentration. Correlations between plant growth and ABA concentrations in planta suggest that ABA-metabolising rhizobacteria may stimulate growth via an ABA-dependent mechanism.
AB - Although endogenous phytohormones such as abscisic acid (ABA) regulate root growth, and many rhizobacteria can modulate root phytohormone status, hitherto there have been no reports of rhizobacteria mediating root ABA concentrations and growth by metabolising ABA. Using a selective ABA-supplemented medium, two bacterial strains were isolated from the rhizosphere of rice (Oryza sativa) seedlings grown in sod-podzolic soil and assigned to Rhodococcus sp. P1Y and Novosphingobium sp. P6W using partial 16S rRNA gene sequencing and phenotypic patterns by the GEN III MicroPlate test. Although strain P6W had more rapid growth in ABA-supplemented media than strain P1Y, both could utilize ABA as a sole carbon source in batch culture. When rice seeds were germinated on filter paper in association with bacteria, root ABA concentration was not affected, but shoot ABA concentration of inoculated plants decreased by 14% (strain P6W) and 22% (strain P1Y). When tomato (Solanum lycopersicum) genotypes differing in ABA biosynthesis (ABA deficient mutants flacca - flc, and notabilis - not and the wild-type cv. Ailsa Craig, WT) were grown in gnotobiotic cultures on nutrient solution agar, rhizobacterial inoculation decreased root and/or leaf ABA concentrations, depending on plant and bacteria genotypes. Strain P6W inhibited primary root elongation of all genotypes, but increased leaf biomass of WT plants. In WT plants treated with silver ions that inhibit ethylene perception, both ABA-metabolising strains significantly decreased root ABA concentration, and strain P6W decreased leaf ABA concentration. Since these changes in ABA status also occurred in plants that were not treated with silver, it suggests that ethylene was probably not involved in regulating bacteria-mediated changes in ABA concentration. Correlations between plant growth and ABA concentrations in planta suggest that ABA-metabolising rhizobacteria may stimulate growth via an ABA-dependent mechanism.
KW - Abscisic acid
KW - Novosphingobium
KW - Phytohormones
KW - Plant-microbe interactions
KW - Rhizosphere
KW - Rhodococcus
KW - VARIOVORAX-PARADOXUS 5C-2
KW - 1-AMINOCYCLOPROPANE-1-CARBOXYLATE DEAMINASE
KW - ACC DEAMINASE
KW - AZOSPIRILLUM-BRASILENSE
KW - PROMOTING BACTERIA
KW - WATER RELATIONS
KW - CULTURE-MEDIUM
KW - DRYING SOIL
KW - WILD-TYPE
KW - TOMATO
U2 - 10.1016/j.plaphy.2013.10.032
DO - 10.1016/j.plaphy.2013.10.032
M3 - Journal article
C2 - 24270514
VL - 74
SP - 84
EP - 91
JO - Plant Physiology and Biochemistry
JF - Plant Physiology and Biochemistry
SN - 0981-9428
ER -