Abstract
Abstract The process of N fixation is energy consuming and inefficient. In most cases 20 to 40% of the energy that is supplied to nitrogenase for the reduction of N 2 is utilized for the reduction of protons to H 2 . Some strains of R. japonicum contain a membrane‐bound hydrogenase that is capable of oxidizing all of the H 2 that is produced during N 2 fixation. This study was conducted to evaluate the effects of inoculation of soybeans [ Glycine max (L.) Merr.] with Rhizobium japonicum containing H 2 recycling capability on N fixation efficiency and soybean yield at various physiological stages of growth. In these experiments, a H 2 ‐oxidizing strain SR (Hup + ) and SR3 (Hup − ), a mutant derived from SR which is unable to oxidize H 2 , were utilized. Soybeans cv. ‘Wilkin’ were grown under bacteriological conditions utilizing a drip‐irrigated nutriculture system. Nodules from plants inoculated with SR evolved no measurable amount of H 2 , while nodules from plants innoculated with SR3 evolved between 2.7 and 10 µ moles of H 2 /g nodules/ hour depending upon physiological age. Acetylene reduction rates by strain SR were significantly higher than those of nodules formed from SR3 during the vegetative, late pod‐fill, and leaf senescence stage of growth, respectively. Dry matter accumulation was significantly higher in plants inoculated with SR than in plants inoculated with SR3 (31% increase during vegetative stage, 25% during flowering, and 27% during pod‐fill stage). Nitrogen contents of shoots and seeds were significantly higher in plants inoculated with strain SR, demonstrating increased N fixation by nodules formed by Hup + Rhizobium . Our results support the conclusion that strains of R. japonicum selected for inoculation purposes should contain H 2 ‐oxidizing capability as one of their desired characteristics.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 8
Claim · model-written summary
SR-inoculated plants had no measurable nodule hydrogen evolution.
Verbatim
e0“Nodules from plants inoculated with SR evolved no measurable amount of H 2”
Claim · model-written summary
SR3-inoculated plants had nodule hydrogen evolution of 2.7 to 10 µ moles per gram per hour.
Verbatim
e0“nodules from plants innoculated with SR3 evolved between 2.7 and 10 µ moles of H 2 /g nodules/ hour depending upon physiological age”
Claim · model-written summary
Acetylene reduction was significantly higher for SR than SR3 nodules at the reported growth stages.
Verbatim
e0“Acetylene reduction rates by strain SR were significantly higher than those of nodules formed from SR3 during the vegetative, late pod‐fill, and leaf senescence stage of growth”
Claim · model-written summary
SR inoculation increased dry matter accumulation 31% during vegetative growth versus SR3.
Verbatim
e0“Dry matter accumulation was significantly higher in plants inoculated with SR than in plants inoculated with SR3 (31% increase during vegetative stage, 25% during flowering, and 27% during pod‐fill stage)”
Claim · model-written summary
SR inoculation increased dry matter accumulation 25% during flowering versus SR3.
Verbatim
e0“Dry matter accumulation was significantly higher in plants inoculated with SR than in plants inoculated with SR3 (31% increase during vegetative stage, 25% during flowering, and 27% during pod‐fill stage)”
Claim · model-written summary
SR inoculation increased dry matter accumulation 27% during pod fill versus SR3.
Verbatim
e0“Dry matter accumulation was significantly higher in plants inoculated with SR than in plants inoculated with SR3 (31% increase during vegetative stage, 25% during flowering, and 27% during pod‐fill stage)”
Claim · model-written summary
SR inoculation produced significantly higher shoot and seed nitrogen contents than SR3.
- Taxon
- plantsViridiplantaee0
- Treatment
- inoculated with strain SRe0
- Interactor
- SRe0symbiont
- Outcome
- Nitrogen contents of shoots and seedse0
- Direction
- highere0
Not reportedComparator
Verbatim
e0“Nitrogen contents of shoots and seeds were significantly higher in plants inoculated with strain SR”
Claim · model-written summary
The authors recommend hydrogen-oxidizing capability in R. japonicum inoculation strains.
Not reportedTaxon
Verbatim
e0“strains of R. japonicum selected for inoculation purposes should contain H 2 ‐oxidizing capability as one of their desired characteristics”
The same questions in other papers
inoculation · yield · Viridiplantae (plants)Positive and negative results
4 papers in the same direction as this paper · 3 in the opposite direction
- no effect
- negative
- negative
4 papers more in this group
See all 8 papers →inoculation · nutrient: content · Viridiplantae (plants)Positive and negative results
17 papers in the same direction as this paper · 1 in the opposite direction
- no effect
- positive
- positive
15 papers more in this group
See all 19 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.