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 - Rhizobacteria that produce auxins and contain 1-amino-cyclopropane-1-carboxylic acid deaminase decrease amino acid concentrations in the rhizosphere and improve growth and yield of well-watered and water-limited potato (Solanum tuberosum)
AU - Belimov, A. A.
AU - Dodd, I. C.
AU - Safronova, V. I.
AU - Shaposhnikov, A. I.
AU - Azarova, T. S.
AU - Makarova, N. M.
AU - Davies, W. J.
AU - Tikhonovich, I. A.
PY - 2015/7
Y1 - 2015/7
N2 - Plant-growth-promoting rhizobacteria (PGPR) utilise amino acids exuded from plant root systems, but hitherto there have been no direct measurements of rhizosphere concentrations of the amino acid 1-amino-cyclopropane-1-carboxylic acid (ACC) following inoculation with PGPR containing the enzyme ACC deaminase. When introduced to the rhizosphere of two potato (Solanum tuberosum) cultivars (cv. Swift and cv. Nevsky), various ACC deaminase containing rhizobacteria (Achromobacter xylosoxidans Cm4, Pseudomonas oryzihabitans Ep4 and Variovorax paradoxus5C-2) not only decreased rhizosphere ACC concentrations but also decreased concentrations of several proteinogenic amino acids (glutamic acid, histidine, isoleucine, leucine, phenylalanine, serine, threonine, tryptophan, tyrosine, valine). These effects were not always correlated with the ability of the bacteria to metabolise these compounds in vitro, suggesting bacterial mediation of root amino acid exudation. All rhizobacteria showed similar root colonisation following inoculation of sand cultures, thus species differences in amino acid utilisation profiles apparently did not confer any selective advantage in the potato rhizosphere. Rhizobacterial inoculation increased root biomass (by up to 50%) and tuber yield (by up to 40%) in pot trials, and tuber yield (by up to 27%) in field experiments, especially when plants were grown under water-limited conditions. Nevertheless, inoculated and control plants showed similar leaf water relations, indicating that alternative mechanisms (regulation of phytohormone balance) were responsible for growth promotion. Rhizobacteria generally increased tuber number more than individual tuber weight, suggesting that accelerated vegetative development was responsible for increased yield.
AB - Plant-growth-promoting rhizobacteria (PGPR) utilise amino acids exuded from plant root systems, but hitherto there have been no direct measurements of rhizosphere concentrations of the amino acid 1-amino-cyclopropane-1-carboxylic acid (ACC) following inoculation with PGPR containing the enzyme ACC deaminase. When introduced to the rhizosphere of two potato (Solanum tuberosum) cultivars (cv. Swift and cv. Nevsky), various ACC deaminase containing rhizobacteria (Achromobacter xylosoxidans Cm4, Pseudomonas oryzihabitans Ep4 and Variovorax paradoxus5C-2) not only decreased rhizosphere ACC concentrations but also decreased concentrations of several proteinogenic amino acids (glutamic acid, histidine, isoleucine, leucine, phenylalanine, serine, threonine, tryptophan, tyrosine, valine). These effects were not always correlated with the ability of the bacteria to metabolise these compounds in vitro, suggesting bacterial mediation of root amino acid exudation. All rhizobacteria showed similar root colonisation following inoculation of sand cultures, thus species differences in amino acid utilisation profiles apparently did not confer any selective advantage in the potato rhizosphere. Rhizobacterial inoculation increased root biomass (by up to 50%) and tuber yield (by up to 40%) in pot trials, and tuber yield (by up to 27%) in field experiments, especially when plants were grown under water-limited conditions. Nevertheless, inoculated and control plants showed similar leaf water relations, indicating that alternative mechanisms (regulation of phytohormone balance) were responsible for growth promotion. Rhizobacteria generally increased tuber number more than individual tuber weight, suggesting that accelerated vegetative development was responsible for increased yield.
KW - ACC deaminase
KW - amino acids
KW - auxin
KW - drought
KW - PGPR
KW - potato
KW - root exudates
KW - VARIOVORAX-PARADOXUS 5C-2
KW - TOMATO ROOT COLONIZATION
KW - BACTERIAL ACC DEAMINASE
KW - PLANT-GROWTH
KW - PROMOTING RHIZOBACTERIA
KW - 1-AMINOCYCLOPROPANE-1-CARBOXYLATE DEAMINASE
KW - PSEUDOMONAS-FLUORESCENS
KW - ABSCISIC-ACID
KW - DRYING SOIL
KW - WHEAT ROOTS
U2 - 10.1111/aab.12203
DO - 10.1111/aab.12203
M3 - Journal article
VL - 167
SP - 11
EP - 25
JO - Annals of Applied Biology
JF - Annals of Applied Biology
SN - 0003-4746
IS - 1
ER -