Nutrient transport across symbiotic membranes from legume nodules

Day, David A.; Kaiser, Brent N.; Thomson, Rowena; Udvardi, Michael K.; Moreau, Sophie; Puppo, Alain

doi:10.1071/pp01028

Cited by 25 publications

(22 citation statements)

References 72 publications

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“…Nitrogen-fixing bacteroids are nondividing cells that have adapted their metabolism to nitrogen fixation and life inside the plant cell (Day et al 2001;Oke and Long 1999a). Whether bacteroids constitute terminally differentiated cells or whether they are able to redifferentiate when they are released from a nodule still remains an unanswered question.…”

Section: Submitted 7 August 2003 Accepted 7 October 2003mentioning

confidence: 99%

Global Changes in Gene Expression in Sinorhizobium meliloti 1021 under Microoxic and Symbiotic Conditions

Becker¹,

Bergès²,

Krol³

et al. 2004

MPMI

242

222

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Sinorhizobium meliloti is an alpha-proteobacterium that alternates between a free-living phase in bulk soil or in the rhizosphere of plants and a symbiotic phase within the host plant cells, where the bacteria ultimately differentiate into nitrogen-fixing organelle-like cells, called bacteroids. As a step toward understanding the physiology of S. meliloti in its free-living and symbiotic forms and the transition between the two, gene expression profiles were determined under two sets of biological conditions: growth under oxic versus microoxic conditions, and in free-living versus symbiotic state. Data acquisition was based on both macro- and microarrays. Transcriptome profiles highlighted a profound modification of gene expression during bacteroid differentiation, with 16% of genes being altered. The data are consistent with an overall slow down of bacteroid metabolism during adaptation to symbiotic life and acquisition of nitrogen fixation capability. A large number of genes of unknown function, including potential regulators, that may play a role in symbiosis were identified. Transcriptome profiling in response to oxygen limitation indicated that up to 5% of the genes were oxygen regulated. However, the microoxic and bacteroid transcriptomes only partially overlap, implying that oxygen contributes to a limited extent to the control of symbiotic gene expression.

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Section: Submitted 7 August 2003 Accepted 7 October 2003mentioning

confidence: 99%

Global Changes in Gene Expression in Sinorhizobium meliloti 1021 under Microoxic and Symbiotic Conditions

Becker¹,

Bergès²,

Krol³

et al. 2004

MPMI

242

222

View full text Add to dashboard Cite

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“…Proteins involved in transport, energy, metabolic processes, nodule formation and function, signaling, pathogen response, and protein destination have been identified from the symbiosome membrane [11][12][13]. Also, channels and bacterial proteins have been identified for this membrane [14][15][16][17]. Proteomics and biochemical purification of single components have been used in soybean, pea, and Lotus systems to identify these biochemical properties of the symbiosome membrane [11][12][13].…”

Section: Introductionmentioning

confidence: 98%

Biochemical characterization of symbiosome membrane proteins from Medicago truncatula root nodules

2004

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The symbiosome membrane represents a specialized plant membrane that forms both a structural and a functional interface between the legume plant and its bacterial counterpart. In this study, the symbiosome membrane protein profile from the model system Medicago truncatula and the corresponding bacterium Sinorhizobium meliloti was examined using two-dimensional electrophoresis and microcapillary high-performance liquid chromatography (HPLC) tandem mass spectrometry. The identities of 51 proteins were obtained and these proteins were categorized into functional classes to indicate biochemical roles. Symbiosome membrane proteins include an H(+)-ATPase, ENOD16, ENOD8, nodulin-25, BiP, HSP70, PDI, multifunctional aquaporin, a putative syntaxin, and other proteins of known and unknown identity and function. The majority of the proteins identified were involved with protein destination and storage. These results allow us to understand better the biochemical composition of the symbiosome membrane and thus provide a basis to hypothesize mechanisms of symbiosome membrane formation and function.

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“…Rhizobia attach to root hairs and grow down plant-derived infection threads into the root cortex (1,3,4). During release from infection threads, rhizobia become surrounded by a plant-derived symbiosome membrane, creating a low-O 2 environment for N 2 fixation to occur (5). Nitrogenase, the enzyme responsible for N 2 fixation, requires at least 16 molecules of magnesium-ATP (MgATP) per molecule of N 2 fixed (N 2 ϩ 8H ϩ ϩ 16MgATP ϩ 8e Ϫ ¡ 2NH 3 ϩ H 2 ϩ 16MgADP ϩ 16P i ) (6).…”

mentioning

confidence: 99%

Role of O ₂ in the Growth of Rhizobium leguminosarum bv. viciae 3841 on Glucose and Succinate

et al. 2017

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Insertion sequencing (INSeq) analysis of Rhizobium leguminosarum bv. viciae 3841 (Rlv3841) grown on glucose or succinate at both 21% and 1% O 2 was used to understand how O 2 concentration alters metabolism. Two transcriptional regulators were required for growth on glucose (pRL120207 [eryD] and RL0547[phoB]), five were required on succinate (pRL100388, RL1641, RL1642, RL3427, and RL4524 [ecfL]), and three were required on 1% O 2 (pRL110072, RL0545 [phoU], and RL4042). A novel toxin-antitoxin system was identified that could be important for generation of new plasmidless rhizobial strains. Rlv3841 appears to use the methylglyoxal pathway alongside the Entner-Doudoroff (ED) pathway and tricarboxylic acid (TCA) cycle for optimal growth on glucose. Surprisingly, the ED pathway was required for growth on succinate, suggesting that sugars made by gluconeogenesis must undergo recycling. Altered amino acid metabolism was specifically needed for growth on glucose, including RL2082 (gatB) and pRL120419 (opaA, encoding omegaamino acid:pyruvate transaminase). Growth on succinate specifically required enzymes of nucleobase synthesis, including ribose-phosphate pyrophosphokinase (RL3468 [prs]) and a cytosine deaminase (pRL90208 [codA]). Succinate growth was particularly dependent on cell surface factors, including the PrsD-PrsE type I secretion system and UDP-galactose production. Only RL2393 (glnB, encoding nitrogen regulatory protein PII) was specifically essential for growth on succinate at 1% O 2 , conditions similar to those experienced by N 2 -fixing bacteroids. Glutamate synthesis is constitutively activated in glnB mutants, suggesting that consumption of 2-ketoglutarate may increase flux through the TCA cycle, leading to excess reductant that cannot be reoxidized at 1% O 2 and cell death.IMPORTANCE Rhizobium leguminosarum, a soil bacterium that forms N 2 -fixing symbioses with several agriculturally important leguminous plants (including pea, vetch, and lentil), has been widely utilized as a model to study Rhizobium-legume symbioses. Insertion sequencing (INSeq) has been used to identify factors needed for its growth on different carbon sources and O 2 levels. Identification of these factors is fundamental to a better understanding of the cell physiology and core metabolism of this bacterium, which adapts to a variety of different carbon sources and O 2 tensions during growth in soil and N 2 fixation in symbiosis with legumes.KEYWORDS INSeq, nodules, Rhizobium leguminosarum, legumes, nitrogen fixation, Pisum sativum R hizobia are alphaproteobacteria able to form symbioses with legumes, on which they induce development of root nodules. Nodules provide an environment with both a low O 2 concentration and the correct nutrients to enable differentiation of rhizobia into nitrogen (N 2 )-fixing bacteroids (1). Bacteroids fix atmospheric N 2 into ammonium (NH 4 ϩ ), which is secreted to the plant host, and are, in turn, provided with

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Nutrient transport across symbiotic membranes from legume nodules

Cited by 25 publications

References 72 publications

Global Changes in Gene Expression in Sinorhizobium meliloti 1021 under Microoxic and Symbiotic Conditions

Global Changes in Gene Expression in Sinorhizobium meliloti 1021 under Microoxic and Symbiotic Conditions

Biochemical characterization of symbiosome membrane proteins from Medicago truncatula root nodules

Role of O ₂ in the Growth of Rhizobium leguminosarum bv. viciae 3841 on Glucose and Succinate

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Nutrient transport across symbiotic membranes from legume nodules

Cited by 25 publications

References 72 publications

Global Changes in Gene Expression in Sinorhizobium meliloti 1021 under Microoxic and Symbiotic Conditions

Global Changes in Gene Expression in Sinorhizobium meliloti 1021 under Microoxic and Symbiotic Conditions

Biochemical characterization of symbiosome membrane proteins from Medicago truncatula root nodules

Role of O 2 in the Growth of Rhizobium leguminosarum bv. viciae 3841 on Glucose and Succinate

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Role of O ₂ in the Growth of Rhizobium leguminosarum bv. viciae 3841 on Glucose and Succinate