Fiziol. rast. genet. 2019, vol. 51, no. 5, 371-387, doi:

Nitrate reductase and its role in legume-rhizobia symbiosis

Kots S.Ya., Mykhalkiv L.M.

  • Institute of Plant Physiology and Genetics, National Academy of Sciences of Ukraine  31/17 Vasylkivska St., 03022, Kyiv, Ukraine

The structure, localization and functioning of nitrate reductase, in particular in legume-rhizobial symbiotic systems, are reviewed. The question of this enzyme synthesis and activity regulation is highlighted. The influence of environmental factors on these processes and the possibility to reduce their inhibitory effect by certain methods are shown. It is noted that in the root nodules of legumes formed as a result of the plant-rhizobia interaction the processes of reduction of nitrate and molecular nitrogen take place. The nitrate reductase and nitrogenase, respectively, are participate in ones. At the presence of the active molecular nitrogen fixation system in the legume plant—nodule bacteria symbiosis, nitrate reductase can interact with nitrogenase differently, depending on the location and type of enzyme, genetic characteristics of symbionts, and cultivation conditions. Hypotheses on the possible mechanisms of this interaction are considered. The data about the distribution of nitrate reductase activity in different nodule zones are presented. The role of nitrate reductase in nitrogen nutrition and plant yield formation is disclosed. A separate place in the review is devoted to the question of the importance of nitric oxide for plants and the participation of nitrate reductase in its synthesis. Possible ways of nitrate reductase functioning optimization with the aim of increasing the efficiency of symbiosis and plant productivity are given.

Keywords: nitrate reductase, nitrogenase, nitrogen nutrition of plants, legume-rhizobia symbiosis, nodules, nitrates, nitric oxide, productivity

Fiziol. rast. genet.
2019, vol. 51, no. 5, 371-387

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