The aim of the present study was to test the hypothesis that the higher nodule amino acid content induced under certain treatments may play a role in the N-feedback regulation of nitrogenase (EC 1.18.6.1) activity by restricting the carbon supply to the functioning nodules. Growing Medicago truncatula plants under sub-optimal phosphorus conditions or upon exposure to large supply of nitrate caused significant asparagine accumulation in nodules of the treated plants. In addition, there was a remarkable decline in the nodule succinate content under phosphorus deprivation while malate was tended to increase. Interestingly, the relative share of succinate in the symbiotic tissues was totally inhibited, i.e. reached zero, by excessive nitrate application. These results provide evidence that succinate might be greatly affected by asparagine content of the nodule fraction, thereby restricting cellular carbon supply to the functioning bacteroids which leads to down-regulation of nodule metabolism and nitrogenase activity.
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http://dx.doi.org/10.1016/j.jplph.2013.12.006 | DOI Listing |
Int J Mol Sci
October 2019
Instituto de Agrobiotecnología (IdAB), Consejo Superior de Investigaciones Científicas-Gobierno de Navarra, 31006 Mutilva, Spain.
Alfalfa ( L.) is frequently constrained by environmental conditions such as drought. Within this context, it is crucial to identify the physiological and metabolic traits conferring a better performance under stressful conditions.
View Article and Find Full Text PDFPlant Cell Environ
November 2019
Graduate School of Agriculture, Hokkaido University, Sapporo, 060-8589, Japan.
To elucidate the mechanism of adaptation of leguminous plants to iron (Fe)-deficient environment, comprehensive analyses of soybean (Glycine max) plants (sampled at anthesis) were conducted under Fe-sufficient control and Fe-deficient treatment using metabolomic and physiological approach. Our results show that soybeans grown under Fe-deficient conditions showed lower nitrogen (N) fixation efficiency; however, ureides increased in different tissues, indicating potential N-feedback inhibition. N assimilation was inhibited as observed in the repressed amino acids biosynthesis and reduced proteins in roots and nodules.
View Article and Find Full Text PDFJ Plant Physiol
March 2014
Signaling Pathway Research Unit, RIKEN Center for Sustainable Resource Science (CSRS), 1-7-22, Suehiro-cho, Tsurumi, Yokohama 230-0045 Japan. Electronic address:
The aim of the present study was to test the hypothesis that the higher nodule amino acid content induced under certain treatments may play a role in the N-feedback regulation of nitrogenase (EC 1.18.6.
View Article and Find Full Text PDFJ Exp Bot
July 2013
Signaling Pathway Research Unit, RIKEN Center for Sustainable Resource Science, 1-7-22, Suehiro-cho, Tsurumi, Yokohama 230-0045, Japan.
Medicago truncatula is an important model plant for characterization of P deficiency on leguminous plants at the physiological and molecular levels. Growth optimization of this plant with regard to P supply is the first essential step for elucidation of the role of P in regulation of nodulation. Hence, a study was carried out to address the growth pattern of M.
View Article and Find Full Text PDFJ Exp Bot
May 2013
Departamento de Ciencias del Medio Natural, Universidad Pública de Navarra, 31006 Pamplona, Spain.
Drought stress is a major factor limiting symbiotic nitrogen fixation (NF) in soybean crop production. However, the regulatory mechanisms involved in this inhibition are still controversial. Soybean plants were symbiotically grown in a split-root system (SRS), which allowed for half of the root system to be irrigated at field capacity while the other half remained water deprived.
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