کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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2055899 | 1075786 | 2014 | 4 صفحه PDF | دانلود رایگان |
SummaryThe 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.
Journal: Journal of Plant Physiology - Volume 171, Issue 6, 15 March 2014, Pages 407–410