Carbon metabolism and bacteroid functioning are involved in the regulation of nitrogen fixation in Medicago truncatula under drought and recovery

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Item Type:	Article
Title:	Carbon metabolism and bacteroid functioning are involved in the regulation of nitrogen fixation in Medicago truncatula under drought and recovery
Creators Name:	Larrainzar, E., Wienkoop, S., Scherling, C., Kempa, S., Ladrera, R., Arrese-Igor, C., Weckwerth, W. and Gonzalez, E.M.
Abstract:	Regulation of symbiotic nitrogen fixation (SNF) during drought stress is complex and not yet fully understood. In the present work, the involvement of nodule C and N metabolism in the regulation of SNF in Medicago truncatula under drought and a subsequent rewatering treatment was analyzed using a combination of metabolomic and proteomic approaches. Drought induced a reduction of SNF rates and major changes in the metabolic profile of nodules, mostly an accumulation of amino acids (Pro, His, and Trp) and carbohydrates (sucrose, galactinol, raffinose, and trehalose). This accumulation was coincidental with a decline in the levels of bacteroid proteins involved in SNF and C metabolism, along with a partial reduction of the levels of plant sucrose synthase 1 (SuSy1). In contrast, the variations in enzymes related to N assimilation were found not to correlate with the reduction in SNF, suggesting that these enzymes do not have a role in the regulation of SNF. Unlike the situation in other legumes such as pea and soybean, the drought-induced inhibition of SNF in M. truncatula appears to be caused by impairment of bacteroid metabolism and N(2)-fixing capacity rather than a limitation of respiratory substrate.
Keywords:	Bacteria, Carbon, Droughts, Gene Expression Profiling, Plant Gene Expression Regulation, Medicago Truncatula, Nitrogen Fixation, Plant Proteins, Water
Source:	Molecular Plant-Microbe Interactions
ISSN:	0894-0282
Publisher:	American Phytopathological Society
Volume:	22
Number:	12
Page Range:	1565-1576
Date:	December 2009
Official Publication:	https://doi.org/10.1094/MPMI-22-12-1565
PubMed:	View item in PubMed

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