Nitrogen fixation and nitrate reduction in the root nodules of legumes |
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| Authors: | Manuel Becana Janet I. Sprent |
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| Affiliation: | Dept of Biological Sciences, Univ. of Dundee, Dundee DDI 4HN, Scotland, UK. |
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| Abstract: | Published data on, and hypotheses regarding the effect of NO−3 on functioning of legume root nodules are reviewed. It is concluded that a short-term reversible effect of NO−3 may act via an increased resistance to O2 diffusion in nodules; this is coupled to decreased bacteroid respiration. For longer exposures to NO−3 nodule activity is irreversibly lost, but how this relates to carbohydrate deprivation or NO-2 accumulation is unclear. Complicating factors include denitrification reactions and the interaction of NO−2 with leghaemoglobin. |
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| Keywords: | Denitrification nitrate assimilation nodule senescence |
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