ubiF is involved in acid stress tolerance and symbiotic competitiveness in Rhizobium favelukesii LPU83
The acidity of soils significantly reduces the productivity of legumes mainly because of the detrimental effects of hydrogen ions on the legume plants, leading to the establishment of an inefficient symbiosis and poor biological nitrogen fixation. We recently reported the analysis of the fully seque...
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Published in | Brazilian journal of microbiology Vol. 53; no. 3; pp. 1633 - 1643 |
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Main Authors | , , , , , , , |
Format | Journal Article |
Language | English |
Published |
Cham
Springer International Publishing
01.09.2022
Springer Nature B.V |
Subjects | |
Online Access | Get full text |
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Summary: | The acidity of soils significantly reduces the productivity of legumes mainly because of the detrimental effects of hydrogen ions on the legume plants, leading to the establishment of an inefficient symbiosis and poor biological nitrogen fixation. We recently reported the analysis of the fully sequenced genome of
Rhizobium favelukesii
LPU83, an alfalfa-nodulating rhizobium with a remarkable ability to grow, nodulate and compete in acidic conditions. To gain more insight into the genetic mechanisms leading to acid tolerance in
R. favelukesii
LPU83, we constructed a transposon mutant library and screened for mutants displaying a more acid-sensitive phenotype than the parental strain. We identified mutant
Tn
833 carrying a single-transposon insertion within
LPU83_2531
, an uncharacterized short ORF located immediately upstream from
ubiF
homolog. This gene encodes a protein with an enzymatic activity involved in the biosynthesis of ubiquinone. As the transposon was inserted near the 3′ end of
LPU83_2531
and these genes are cotranscribed as a part of the same operon, we hypothesized that the phenotype in
Tn
833 is most likely due to a polar effect on
ubiF
transcription.
We found that a mutant in
ubiF
was impaired to grow at low pH and other abiotic stresses including 5 mM ascorbate and 0.500 mM Zn
2+
. Although the
ubiF
mutant retained the ability to nodulate alfalfa and
Phaseolus vulgaris
, it was unable to compete with the
R. favelukesii
LPU83 wild-type strain for nodulation in
Medicago sativa
and
P. vulgaris
, suggesting that
ubiF
is important for competitiveness. Here, we report for the first time an
ubiF
homolog being essential for nodulation competitiveness and tolerance to specific stresses in rhizobia.
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 1517-8382 1678-4405 |
DOI: | 10.1007/s42770-022-00780-8 |