Publications

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a medicago truncatula h+-pyrophosphatase gene, mtvp1, improves sucrose accumulation and anthocyanin biosynthesis in potato (solanum tuberosum l.).we recently cloned mtvp1, a type i vacuolar-type h(+)-translocating inorganic pyrophosphatase from medicago truncatula. in the present study, we investigated the cellular location and the function of this h(+)-ppase in arabidopsis and potato (solanum tuberosum l.). an mtvp1::enhanced green fluorescent protein fusion was constructed, which localized to the plasma membrane of onion epidermal cells. transgenic arabidopsis thaliana overexpressing mtvp1 had more robust root systems and redder shoots ...201424854441
overexpression of medicago svp genes causes floral defects and delayed flowering in arabidopsis but only affects floral development in medicago.the mads-domain transcription factor short vegetative phase plays a key role as a repressor of the transition to flowering and as a regulator of early floral development in arabidopsis thaliana (arabidopsis). however, no flowering-time repressors have been functionally identified in the model legume medicago truncatula (medicago). in this study, phylogenetic analysis of two closely-related mtsvp-like sequences, mtsvp1 and mtsvp2, showed that their predicted proteins clustered together within the ...201424249713
lateral root formation and patterning in medicago truncatula.the plant root system is crucial for anchorage and nutrition, and has a major role in plant adaptation, as well as in interactions with soil micro-organisms. despite the agronomical and ecological importance of legume plants, whose roots can interact symbiotically with soil bacteria called rhizobia that fix atmospheric dinitrogen, and the evidence that lateral root (lr) development programmes are intercepted and influenced by symbiotic organisms, very little is known concerning the cellular and ...201424148318
comparative genomic and transcriptomic analysis of terpene synthases in arabidopsis and medicago.this study provides a timely comparative genomic and transcriptomic analysis of the terpene synthase (tps) gene family in medicago truncatula (bears glandular and non-glandular trichomes) and arabidopsis thaliana (bears non-glandular trichomes). the authors' efforts aimed to gain insight into tps function, phylogenetic relationships and the role of trichomes in terpene biosynthesis and function. in silico analysis identified 33 and 23 putative full-length tps genes in arabidopsis and medicago, r ...201425075527
genome-wide determination of poly(a) sites in medicago truncatula: evolutionary conservation of alternative poly(a) site choice.alternative polyadenylation (apa) plays an important role in the post-transcriptional regulation of gene expression. little is known about how apa sites may evolve in homologous genes in different plant species. to this end, comparative studies of apa sites in different organisms are needed. in this study, a collection of poly(a) sites in medicago truncatula, a model system for legume plants, has been generated and compared with apa sites in arabidopsis thaliana.201425048171
study on folate binding domain of dihydrofolate reductase in different plant species and human beings.data base (ncbi and tigr) searches are made to retrieve protein sequences of different plant species namely medicago truncatula, pisum sativum, ricinus communis, arabidopsis thaliana, vitis vinifera, glycine max, daucus carota, oryza sativa japonica group, arabidopsis lyrata subsp. lyrata, brachypodium distachyon, oryza sativa indica group, zea mays and careful alignment of derived sequences shows 95% or higher identity. similarly, dhfr sequence of human being is also retrieved from ncbi. a phyl ...201424616563
early transcriptional responses to mercury: a role for ethylene in mercury-induced stress.understanding the cellular mechanisms of plant tolerance to mercury (hg) is important for developing phytoremediation strategies of hg-contaminated soils. the early responses of alfalfa (medicago sativa) seedlings to hg were studied using transcriptomics analysis. a medicago truncatula microarray was hybridized with high-quality root rna from m. sativa treated with 3 μm hg for 3, 6 and 24 h. the transcriptional pattern data were complementary to the measurements of root growth inhibition, lipid ...201424033367
prediction of plant pre-micrornas and their micrornas in genome-scale sequences using structure-sequence features and support vector machine.micrornas (mirnas) are a family of non-coding rnas approximately 21 nucleotides in length that play pivotal roles at the post-transcriptional level in animals, plants and viruses. these molecules silence their target genes by degrading transcription or suppressing translation. studies have shown that mirnas are involved in biological responses to a variety of biotic and abiotic stresses. identification of these molecules and their targets can aid the understanding of regulatory processes. recent ...201425547126
[influence of salt stress on the genetically polymorphic system of sinorhizobium meliloti-medicago truncatula].the impacts of salt stress (75 mm nac1) on the ecological efficiency of the genetically polymorphic sinorhizobium meliloti-medicago truncatula system were studied. its impact on a symbiotic system results in an increase of the partners' variability for symbiotic traits and of the symbiosis integrity as indicated by: a) the specificity of the partners' interactions--the nonadditive inputs of their genotypes into the variation of symbiotic parameters; and b) the correlative links between these par ...201425720135
characterization of five subgroups of the sieve element occlusion gene family in glycine max reveals genes encoding non-forisome p-proteins, forisomes and forisome tails.p-proteins are structural phloem proteins discussed to be involved in the rapid sealing of injured sieve elements. p-proteins are found in all dicotyledonous and some monocotyledonous plants, but additional crystalloid p-proteins, known as forisomes, have evolved solely in the fabaceae. both types are encoded by members of the sieve element occlusion (seo) gene family, which comprises seven phylogenetic subgroups. the fabaceae-specific subgroup 1 contains genes encoding forisome subunits in e.g. ...201424928491
involvement of papain and legumain proteinase in the senescence process of medicago truncatula nodules.the symbiotic interaction between legumes and rhizobiaceae leads to the formation of new root organs called nodules. within the nodule, rhizobiaceae differentiate into nitrogen-fixing bacteroids. however, this symbiotic interaction is time-limited as a result of the initiation of a senescence process, leading to a complete degradation of bacteroids and host plant cells. the increase in proteolytic activity is one of the key features of this process. in this study, we analysed the involvement of ...201424527680
an integrated analysis of plant and bacterial gene expression in symbiotic root nodules using laser-capture microdissection coupled to rna sequencing.rhizobium-induced root nodules are specialized organs for symbiotic nitrogen fixation. indeterminate-type nodules are formed from an apical meristem and exhibit a spatial zonation which corresponds to successive developmental stages. to get a dynamic and integrated view of plant and bacterial gene expression associated with nodule development, we used a sensitive and comprehensive approach based upon oriented high-depth rna sequencing coupled to laser microdissection of nodule regions. this stud ...201424483147
local and systemic proteomic changes in medicago truncatula at an early phase of sinorhizobium meliloti infection.a symbiotic association with n-fixing bacteria facilitates the growth of leguminous plants under nitrogen-limiting conditions. the establishment of the symbiosis requires signal exchange between the host and the bacterium, which leads to the formation of root nodules, inside which bacteria are hosted. the formation of nodules is controlled through local and systemic mechanisms, which involves root-shoot communication. our study was aimed at investigating the proteomic changes occurring in shoots ...201424350862
mtzr1, a praf protein, is involved in the development of roots and symbiotic root nodules in medicago truncatula.praf proteins are present in all plants, but their functions remain unclear. we investigated the role of one member of the praf family, mtzr1, on the development of roots and nitrogen-fixing nodules in medicago truncatula. we found that mtzr1 was expressed in all m. truncatula organs. spatiotemporal analysis showed that mtzr1 expression in m. truncatula roots was mostly limited to the root meristem and the vascular bundles of mature nodules. mtzr1 expression in root nodules was down-regulated in ...201423961805
pea aphid biotype performance on diverse medicago host genotypes indicates highly specific virulence and resistance functions.aphid-plant interactions depend on genotypes of both organisms, which determine the two-way molecular exchange that leads to compatible or incompatible outcomes. the underlying genes are mostly unknown, making it difficult to predict likelihood of aphid success or host resistance, and hampering crop genetic improvement. here we screened eight pea aphid clonal genotypes collected from diverse legume hosts, on a species-wide panel of medicago truncatula (mt) genotypes. aphid virulence was measured ...201425375216
elevated co2 alters the feeding behaviour of the pea aphid by modifying the physical and chemical resistance of medicago truncatula.elevated co(2) compromises the resistance of leguminous plants against chewing insects, but little is known about whether elevated co(2) modifies the resistance against phloem-sucking insects or whether it has contrasting effects on the resistance of legumes that differ in biological nitrogen fixation. we tested the hypothesis that the physical and chemical resistance against aphids would be increased in jemalong (a wild type of medicago truncatula) but would be decreased in dnf1 (a mutant witho ...201424697655
elevated co2 decreases the response of the ethylene signaling pathway in medicago truncatula and increases the abundance of the pea aphid.the performance of herbivorous insects is greatly affected by plant nutritional quality and resistance, which are likely to be altered by rising concentrations of atmospheric co2 . we previously reported that elevated co2 enhanced biological nitrogen (n) fixation of medicago truncatula, which could result in an increased supply of amino acids to the pea aphid (acyrthosiphon pisum). the current study examined the n nutritional quality and aphid resistance of sickle, an ethylene-insensitive mutant ...201424015892
[optimization of synthetic pathway and fermentation process of yeast cell factories for production of oleanoic acid].to optimize the synthetic pathway and fermentation process of yeast cell factories for production of oleanoic acid.201425272488
a nitrogen-dependent switch in the high affinity ammonium transport in medicago truncatula.ammonium transporters (amts) are crucial for the high affinity primary uptake and translocation of ammonium in plants. in the model legume medicago truncatula, the genomic set of amt-type ammonium transporters comprises eight members. only four genes were abundantly expressed in young seedlings, both in roots and shoots. while the expression of all amts in the shoot was not affected by the nitrogen availability, the dominating mtamt1;1 gene was repressed by nitrogen in roots, despite that cellul ...201425164101
unravelling the triterpenoid saponin biosynthesis of the african shrub maesa lanceolata.maesasaponins produced by the african shrub maesa lanceolata are oleanane-type saponins with diverse biological activities. candidate maesasaponin biosynthesis genes were identified through transcript profiling of m. lanceolata shoot cultures treated with methyl jasmonate, a well-known elicitor of plant specialized metabolism. heterologous expression of the identified genes in saccharomyces cerevisiae led to the identification of one oxidosqualene cyclase (mlbas) and two cytochrome p450s, cyp716 ...201425296856
enhanced nodulation and nodule development by nolr mutants of sinorhizobium medicae on specific medicago host genotypes.the nolr gene encodes a negatively acting, transcriptional regulatory protein of core nod-factor biosynthetic genes in the sinorhizobia. although previous reports showed that nolr modulates nod-factor production and enhances nodulation speed of sinorhizobium meliloti on alfalfa, there have been no reports for the symbiotic function of this gene in the s. medicae-medicago truncatula symbiosis. here, we constructed an nolr mutant of s. medicae wsm419 and evaluated mutant and wild-type strains for ...201424283939
response of medicago truncatula seedlings to colonization by salmonella enterica and escherichia coli o157:h7.disease outbreaks due to the consumption of legume seedlings contaminated with human enteric bacterial pathogens like escherichia coli o157:h7 and salmonella enterica are reported every year. besides contaminations occurring during food processing, pathogens present on the surface or interior of plant tissues are also responsible for such outbreaks. in the present study, surface and internal colonization of medicago truncatula, a close relative of alfalfa, by salmonella enterica and escherichia ...201424551073
the symbiotic transcription factor mtefd and cytokinins are positively acting in the medicago truncatula and ralstonia solanacearum pathogenic interaction.• a plant-microbe dual biological system was set up involving the model legume medicago truncatula and two bacteria, the soil-borne root pathogen ralstonia solanacearum and the beneficial symbiont sinorhizobium meliloti. • comparison of transcriptomes under symbiotic and pathogenic conditions highlighted the transcription factor mtefd (ethylene response factor required for nodule differentiation) as being upregulated in both interactions, together with a set of cytokinin-related transcripts invo ...201424325235
comparative analysis of cyp93e proteins for improved microbial synthesis of plant triterpenoids.cytochrome p450-dependent monooxygenases (p450s) belonging to the cyp93e subfamily catalyze the c-24 oxidation of the triterpene backbone during the biosynthesis of triterpenoid saponins, which are bioactive plant natural products. in our attempts to produce plant triterpenoids in the yeast saccharomyces cerevisiae, we observed a poor in vivo catalytic efficiency of the medicago truncatula cyp93e2. to overcome this biosynthetic bottleneck, we screened publicly available plant genome and transcri ...201425453910
heterologous overexpression of vigna radiata epoxide hydrolase in escherichia coli and its catalytic performance in enantioconvergent hydrolysis of p-nitrostyrene oxide into (r)-p-nitrophenyl glycol.two native epoxide hydrolases (ehs) were previously discovered from mung bean powder (vigna radiata), both of which can catalyze the enantioconvergent hydrolysis of p-nitrostyrene oxide (pnso). in this study, the encoding gene of vreh1 was successfully cloned from the cdna of v. radiata by rt-pcr and rapid amplification of cdna ends (race) technologies. high homologies were found to two putative ehs originated from glycine max (80%) and medicago truncatula (79%). the vreh1 gene constructed in pe ...201423615737
a virus inhibitory protein isolated from cyamopsis tetragonoloba (l.) taub. upon induction of systemic antiviral resistance shares partial amino acid sequence homology with a lectin.two virus inhibitory proteins were purified from cyamopsis tetragonoloba , induced to resist virus infections by cip-29, a systemic resistance inducing protein from clerodendrum inerme, and characterized. one of them shared homology with a lectin. cip-29, a known 29 kda systemic antiviral resistance inducing protein isolated from clerodendrum inerme, has been used to induce systemic resistance in cyamopsis tetragonoloba against sunn-hemp rosette virus (srv). paper reports the detection of virus ...201424828329
isolation and characterization of putative endophytic bacteria antagonistic to phoma tracheiphila and verticillium albo-atrum.a collection of 200 bacterial isolates recovered from citrus plants (citrus limon, citrus sinensis, and citrus reticulata), medicago truncatula and laurus nobilis, was established. in vitro screening indicated that 28 isolates exhibited an inhibitory activity against the vascular pathogens phoma tracheiphila and verticillium albo-atrum. isolates were screened according to their hydrolytic activities, plant growth-promoting bacteria (pgpb) abilities, as well as for the presence of nonribosomal pe ...201425074353
isolation and characterization of genetic variability in bacteria with β-hemolytic and antifungal activity isolated from the rhizosphere of medicago truncatula plants.in the present study, we analyzed the frequency of hemolytic and antifungal activities in bacterial isolates from the rhizosphere of medicago truncatula plants. of the 2000 bacterial colonies, 96 showed β-hemolytic activities (frequency, 4.8 x 10(-2)). hemolytic isolates were analyzed for their genetic diversity by using random amplification of polymorphic dna, yielding 88 haplotypes. the similarity coefficient of nei and li showed a polymorphic diversity ranging from 0.3 to 1. additionally, 8 o ...201425062484
multifaceted investigation of metabolites during nitrogen fixation in medicago via high resolution maldi-ms imaging and esi-ms.legumes have developed the unique ability to establish a symbiotic relationship with soil bacteria known as rhizobia. this interaction results in the formation of root nodules in which rhizobia thrive and reduce atmospheric dinitrogen into plant-usable ammonium through biological nitrogen fixation (bnf). owing to the availability of genetic information for both of the symbiotic partners, the medicago truncatula-sinorhizobium meliloti association is an excellent model for examining the bnf proces ...201425323862
nodule carbohydrate catabolism is enhanced in the medicago truncatula a17-sinorhizobium medicae wsm419 symbiosis.the symbiotic association between medicago truncatula and sinorhizobium meliloti is a well-established model system in the legume-rhizobium community. despite its wide use, the symbiotic efficiency of this model has been recently questioned and an alternative microsymbiont, s. medicae, has been proposed. however, little is known about the physiological mechanisms behind the higher symbiotic efficiency of s. medicae wsm419. in the present study, we inoculated m. truncatula jemalong a17 with eithe ...201425221545
genomic characterization of the leed..peeds, a gene family unique to the medicago lineage.the leed..peed (lp) gene family in medicago truncatula (a17) is composed of 13 genes coding small putatively secreted peptides with one to two conserved domains of negatively charged residues. this family is not present in the genomes of glycine max, lotus japonicus, or the irlc species cicer arietinum. lp genes were also not detected in a trifolium pratense draft genome or pisum sativum nodule transcriptome, which were sequenced de novo in this study, suggesting that the lp gene family arose wi ...201425155275
identification of a dominant gene in medicago truncatula that restricts nodulation by sinorhizobium meliloti strain rm41.leguminous plants are able to form a root nodule symbiosis with nitrogen-fixing soil bacteria called rhizobia. this symbiotic association shows a high level of specificity. beyond the specificity for the legume family, individual legume species/genotypes can only interact with certain restricted group of bacterial species or strains. specificity in this system is regulated by complex signal exchange between the two symbiotic partners and thus multiple genetic mechanisms could be involved in the ...201424934080
comprehensive characterization and rna-seq profiling of the hd-zip transcription factor family in soybean (glycine max) during dehydration and salt stress.the homeodomain leucine zipper (hd-zip) transcription factor family is one of the largest plant specific superfamilies, and includes genes with roles in modulation of plant growth and response to environmental stresses. many hd-zip genes are characterized in arabidopsis (arabidopsis thaliana), and members of the family are being investigated for abiotic stress responses in rice (oryza sativa), maize (zea mays), poplar (populus trichocarpa) and cucumber (cucmis sativus). findings in these species ...201425362847
direct purification of detergent-insoluble membranes from medicago truncatula root microsomes: comparison between floatation and sedimentation.membrane microdomains are defined as highly dynamic, sterol- and sphingolipid-enriched domains that resist to solubilization by non-ionic detergents. in plants, these so-called detergent insoluble membrane (dim) fractions have been isolated from plasma membrane by using conventional ultracentrifugation on density gradient (g). in animals, a rapid (r) protocol, based on sedimentation at low speed, which avoids the time-consuming sucrose gradient, has also been developed to recover dims from micro ...201425267185
genome-wide identification and expression profiling analysis of the aux/iaa gene family in medicago truncatula during the early phase of sinorhizobium meliloti infection.auxin/indoleacetic acid (aux/iaa) genes, coding a family of short-lived nuclear proteins, play key roles in wide variety of plant developmental processes, including root system regulation and responses to environmental stimulus. however, how they function in auxin signaling pathway and symbiosis with rhizobial in medicago truncatula are largely unknown. the present study aims at gaining deeper insight on distinctive expression and function features of aux/iaa family genes in medicago truncatula ...201425226164
symbiotic plant peptides eliminate candida albicans both in vitro and in an epithelial infection model and inhibit the proliferation of immortalized human cells.the increasing number of multidrug-resistant microbes now emerging necessitates the identification of novel antimicrobial agents. plants produce a great variety of antimicrobial peptides including hundreds of small, nodule-specific cysteine-rich ncr peptides that, in the legume medicago truncatula, govern the differentiation of endosymbiotic nitrogen fixing bacteria and, in vitro, can display potent antibacterial activities. in this study, the potential candidacidal activity of 19 ncr peptides w ...201425243129
rna-seq transcriptome profiling reveals that medicago truncatula nodules acclimate n₂ fixation before emerging p deficiency reaches the nodules.legume nodules are plant tissues with an exceptionally high concentration of phosphorus (p), which, when there is scarcity of p, is preferentially maintained there rather than being allocated to other plant organs. the hypothesis of this study was that nodules are affected before the p concentration in the organ declines during whole-plant p depletion. nitrogen (n₂) fixation and p concentration in various organs were monitored during a whole-plant p-depletion process in medicago truncatula. nodu ...201425151618
the 2ha line of medicago truncatula has characteristics of an epigenetic mutant that is weakly ethylene insensitive.the medicago truncatula 2ha seed line is highly embryogenic while the parental line jemalong rarely produces embryos. the 2ha line was developed from one of the rare jemalong regenerates and this method for obtaining a highly regenerable genotype in m. truncatula is readily reproducible suggesting an epigenetic mechanism. microarray transcriptomic analysis showed down regulation of an ethylene insensitive 3-like gene in 2ha callus which provided an approach to investigating epigenetic regulation ...201424952658
plant responses to bacterial n-acyl l-homoserine lactones are dependent on enzymatic degradation to l-homoserine.many bacteria use quorum sensing (qs) to regulate phenotypes that ultimately benefit the bacterial population at high cell densities. these qs-dependent phenotypes are diverse and can have significant impacts on the bacterial host, including virulence factor production, motility, biofilm formation, bioluminescence, and root nodulation. as bacteria and their eukaryotic hosts have coevolved over millions of years, it is not surprising that certain hosts appear to be able to sense qs signals, poten ...201424918118
keel petal incision: a simple and efficient method for genetic crossing in medicago truncatula.genetic crossing is an essential tool in both forward and reverse genetic approaches to understand the biological functions of genes. for medicago truncatula (barrel medic) various crossing techniques have been used which differ in the methods used to dissect the female parent's unopened flower bud to remove immature anthers for prevention of self-pollination. previously described methods including front, side or back incision methods may damage the flower bud, impeding successful fertilization ...201424966878
the activity of nodules of the supernodulating mutant mtsunn is not limited by photosynthesis under optimal growth conditions.legumes match the nodule number to the n demand of the plant. when a mutation in the regulatory mechanism deprives the plant of that ability, an excessive number of nodules are formed. these mutants show low productivity in the fields, mainly due to the high carbon burden caused through the necessity to supply numerous nodules. the objective of this study was to clarify whether through optimal conditions for growth and co2 assimilation a higher nodule activity of a supernodulating mutant of medi ...201424727372
patterns of divergence of a large family of nodule cysteine-rich peptides in accessions of medicago truncatula.the nodule cysteine-rich (ncr) groups of defensin-like (defl) genes are one of the largest gene families expressed in the nodules of some legume plants. they have only been observed in the inverted repeat loss clade (irlc) of legumes, which includes the model legume medicago truncatula. ncrs are reported to play an important role in plant-microbe interactions. to understand their diversity we analyzed their expression and sequence polymorphisms among four accessions of m. truncatula. a significa ...201424635121
genome sequence of the medicago-nodulating ensifer meliloti commercial inoculant strain rri128.ensifer meliloti strain rri128 is an aerobic, motile, gram-negative, non-spore-forming rod. rri128 was isolated from a nodule recovered from the roots of barrel medic (medicago truncatula) grown in the greenhouse and inoculated with soil collected from victoria, australia. the strain is used in commercial inoculants in australia. rri128 nodulates and forms an effective symbiosis with a diverse range of lucerne cultivars (medicago sativa) and several species of annual medic (m. truncatula, medica ...201425197447
the small rna diversity from medicago truncatula roots under biotic interactions evidences the environmental plasticity of the mirnaome.legume roots show a remarkable plasticity to adapt their architecture to biotic and abiotic constraints, including symbiotic interactions. however, global analysis of mirna regulation in roots is limited, and a global view of the evolution of mirna-mediated diversification in different ecotypes is lacking.201425248950
the alternative medicago truncatula defense proteome of ros-defective transgenic roots during early microbial infection.rop-type gtpases of plants function as molecular switches within elementary signal transduction pathways such as the regulation of ros synthesis via activation of nadph oxidases (rboh-respiratory burst oxidase homolog in plants). previously, we reported that silencing of the medicago truncatula gtpase mtrop9 led to reduced ros production and suppressed induction of ros-related enzymes in transgenic roots (mtrop9i) infected with pathogenic (aphanomyces euteiches) and symbiotic microorganisms (glo ...201425101099
a sinorhizobium meliloti-specific n-acyl homoserine lactone quorum-sensing signal increases nodule numbers in medicago truncatula independent of autoregulation.n-acyl homoserine lactones (ahls) act as quorum sensing signals that regulate cell-density dependent behaviors in many gram-negative bacteria, in particular those important for plant-microbe interactions. ahls can also be recognized by plants, and this may influence their interactions with bacteria. here we tested whether the exposure to ahls affects the nodule-forming symbiosis between legume hosts and rhizobia. we treated roots of the model legume, medicago truncatula, with a range of ahls eit ...201425352858
extreme specificity of ncr gene expression in medicago truncatula.legumes form root nodules to house nitrogen fixing bacteria of the rhizobium family. the rhizobia are located intracellularly in the symbiotic nodule cells. in the legume medicago truncatula these cells produce high amounts of nodule-specific cysteine-rich (ncr) peptides which induce differentiation of the rhizobia into enlarged, polyploid and non-cultivable bacterial cells. ncrs are similar to innate immunity antimicrobial peptides. the ncr gene family is extremely large in medicago with about ...201425156206
growth conditions determine the dnf2 requirement for symbiosis.rhizobia and legumes are able to interact in a symbiotic way leading to the development of root nodules. within nodules, rhizobia fix nitrogen for the benefit of the plant. these interactions are efficient because spectacularly high densities of nitrogen fixing rhizobia are maintained in the plant cells. dnf2, a medicago truncatula gene has been described as required for nitrogen fixation, bacteroid's persistence and to prevent defense-like reactions in the nodules. this manuscript shows that a ...201424632747
characterization of four bifunctional plant iam/pam-amidohydrolases capable of contributing to auxin biosynthesis.amidases [ec 3.5.1.4] capable of converting indole-3-acetamide (iam) into the major plant growth hormone indole-3-acetic acid (iaa) are assumed to be involved in auxin de novo biosynthesis. with the emerging amount of genomics data, it was possible to identify over forty proteins with substantial homology to the already characterized amidases from arabidopsis and tobacco. the observed high conservation of amidase-like proteins throughout the plant kingdom may suggest an important role of theses ...201427135507
nod factor receptors form heteromeric complexes and are essential for intracellular infection in medicago nodules.rhizobial nod factors are the key signaling molecules in the legume-rhizobium nodule symbiosis. in this study, the role of the nod factor receptors nod factor perception (nfp) and lysin motif receptor-like kinase3 (lyk3) in establishing the symbiotic interface in root nodules was investigated. it was found that inside medicago truncatula nodules, nfp and lyk3 localize at the cell periphery in a narrow zone of about two cell layers at the nodule apex. this restricted accumulation is narrower than ...201425351493
intracellular catalytic domain of symbiosis receptor kinase hyperactivates spontaneous nodulation in absence of rhizobia.symbiosis receptor kinase (symrk), a member of the nod factor signaling pathway, is indispensible for both nodule organogenesis and intracellular colonization of symbionts in rhizobia-legume symbiosis. here, we show that the intracellular kinase domain of a symrk (symrk-kd) but not its inactive or full-length version leads to hyperactivation of the nodule organogenic program in medicago truncatula tr25 (symrk knockout mutant) in the absence of rhizobia. spontaneous nodulation in tr25/symrk-kd wa ...201425304318
abscisic acid promotion of arbuscular mycorrhizal colonization requires a component of the protein phosphatase 2a complex.legumes can establish intracellular interactions with symbiotic microbes to enhance their fitness, including the interaction with arbuscular mycorrhizal (am) fungi. am fungi colonize root epidermal cells to gain access to the root cortex, and this requires the recognition by the host plant of fungus-made mycorrhizal factors. genetic dissection has revealed the symbiosis signaling pathway that allows the recognition of am fungi, but the downstream processes that are required to promote fungal inf ...201425293963
adjustment of host cells for accommodation of symbiotic bacteria: vacuole defunctionalization, hops suppression, and tip1g retargeting in medicago.in legume-rhizobia symbioses, the bacteria in infected cells are enclosed in a plant membrane, forming organelle-like compartments called symbiosomes. symbiosomes remain as individual units and avoid fusion with lytic vacuoles of host cells. we observed changes in the vacuole volume of infected cells and thus hypothesized that microsymbionts may cause modifications in vacuole formation or function. to examine this, we quantified the volumes and surface areas of plant cells, vacuoles, and symbios ...201425217511
the root hair "infectome" of medicago truncatula uncovers changes in cell cycle genes and reveals a requirement for auxin signaling in rhizobial infection.nitrogen-fixing rhizobia colonize legume roots via plant-made intracellular infection threads. genetics has identified some genes involved but has not provided sufficient detail to understand requirements for infection thread development. therefore, we transcriptionally profiled medicago truncatula root hairs prior to and during the initial stages of infection. this revealed changes in the responses to plant hormones, most notably auxin, strigolactone, gibberellic acid, and brassinosteroids. sev ...201425527707
local and systemic regulation of plant root system architecture and symbiotic nodulation by a receptor-like kinase.in plants, root system architecture is determined by the activity of root apical meristems, which control the root growth rate, and by the formation of lateral roots. in legumes, an additional root lateral organ can develop: the symbiotic nitrogen-fixing nodule. we identified in medicago truncatula ten allelic mutants showing a compact root architecture phenotype (cra2) independent of any major shoot phenotype, and that consisted of shorter roots, an increased number of lateral roots, and a redu ...201425521478
a h+-atpase that energizes nutrient uptake during mycorrhizal symbioses in rice and medicago truncatula.most plant species form symbioses with arbuscular mycorrhizal (am) fungi, which facilitate the uptake of mineral nutrients such as phosphate from the soil. several transporters, particularly proton-coupled phosphate transporters, have been identified on both the plant and fungal membranes and contribute to delivering phosphate from fungi to plants. the mechanism of nutrient exchange has been studied in plants during mycorrhizal colonization, but the source of the electrochemical proton gradient ...201424781115
the h+-atpase ha1 of medicago truncatula is essential for phosphate transport and plant growth during arbuscular mycorrhizal symbiosis.a key feature of arbuscular mycorrhizal symbiosis is improved phosphorus nutrition of the host plant via the mycorrhizal pathway, i.e., the fungal uptake of pi from the soil and its release from arbuscules within root cells. efficient transport of pi from the fungus to plant cells is thought to require a proton gradient across the periarbuscular membrane (pam) that separates fungal arbuscules from the host cell cytoplasm. previous studies showed that the h(+)-atpase gene ha1 is expressed specifi ...201424781114
abscisic acid and lateral root organ defective/numerous infections and polyphenolics modulate root elongation via reactive oxygen species in medicago truncatula.abscisic acid (aba) modulates root growth in plants grown under normal and stress conditions and can rescue the root growth defects of the medicago truncatula lateral root-organ defective (latd) mutant. here, we demonstrate that reactive oxygen species (ros) function downstream of aba in the regulation of root growth by controlling cell elongation. we also show that the mtlatd/numerous infections and polyphenolics (nip) nitrate transporter is required for ros homeostasis and cell elongation in r ...201425192698
medicago truncatula symbiotic peptide ncr247 contributes to bacteroid differentiation through multiple mechanisms.symbiosis between rhizobia soil bacteria and legume plants results in the formation of root nodules where plant cells are fully packed with nitrogen fixing bacteria. in the host cells, the bacteria adapt to the intracellular environment and gain the ability for nitrogen fixation. depending on the host plants, the symbiotic fate of bacteria can be either reversible or irreversible. in medicago and related legume species, the bacteria undergo a host-directed multistep differentiation process culmi ...201424706863
mir171h restricts root symbioses and shows like its target nsp2 a complex transcriptional regulation in medicago truncatula.legumes have the unique capability to undergo root nodule and arbuscular mycorrhizal symbiosis. both types of root endosymbiosis are regulated by nsp2, which is a target of microrna171h (mir171h). although, recent data implies that mir171h specifically restricts arbuscular mycorrhizal symbiosis in the root elongation zone of medicago truncatula roots, there is limited knowledge available about the spatio-temporal regulation of mir171h expression at different physiological and symbiotic condition ...201425928247
molecular and ultrastructural analysis of forisome subunits reveals the principles of forisome assembly.forisomes are specialized structural phloem proteins that mediate sieve element occlusion after wounding exclusively in papilionoid legumes, but most studies of forisome structure and function have focused on the old world clade rather than the early lineages. a comprehensive phylogenetic, molecular, structural and functional analysis of forisomes from species covering a broad spectrum of the papilionoid legumes was therefore carried out, including the first analysis of dipteryx panamensis foris ...201424694827
auxin perception is required for arbuscule development in arbuscular mycorrhizal symbiosis.most land plant species live in symbiosis with arbuscular mycorrhizal fungi. these fungi differentiate essential functional structures called arbuscules in root cortical cells from which mineral nutrients are released to the plant. we investigated the role of microrna393 (mir393), an mirna that targets several auxin receptors, in arbuscular mycorrhizal root colonization. expression of the precursors of the mir393 was down-regulated during mycorrhization in three different plant species: solanum ...201425096975
the nitrate transporter mtnpf6.8 (mtnrt1.3) transports abscisic acid and mediates nitrate regulation of primary root growth in medicago truncatula.elongation of the primary root during postgermination of medicago truncatula seedlings is a multigenic trait that is responsive to exogenous nitrate. a quantitative genetic approach suggested the involvement of the nitrate transporter mtnpf6.8 (for medicago truncatula nitrate transporter1/peptide transporter family6.8) in the inhibition of primary root elongation by high exogenous nitrate. in this study, the inhibitory effect of nitrate on primary root elongation, via inhibition of elongation of ...201425367858
myb5 and myb14 play pivotal roles in seed coat polymer biosynthesis in medicago truncatula.in arabidopsis (arabidopsis thaliana), the major myb protein regulating proanthocyanidin (pa) biosynthesis is tt2, named for the transparent testa phenotype of tt2 mutant seeds that lack pas in their coats. in contrast, the myb5 transcription factor mainly regulates seed mucilage biosynthesis and trichome branching, with only a minor role in pa biosynthesis. we here characterize myb5 and myb14 (a tt2 homolog) in the model legume medicago truncatula. overexpression of mtmyb5 or mtmyb14 strongly i ...201424948832
high phosphate reduces host ability to develop arbuscular mycorrhizal symbiosis without affecting root calcium spiking responses to the fungus.the arbuscular mycorrhizal symbiosis associates soil fungi with the roots of the majority of plants species and represents a major source of soil phosphorus acquisition. mycorrhizal interactions begin with an exchange of molecular signals between the two partners. a root signaling pathway is recruited, for which the perception of fungal signals triggers oscillations of intracellular calcium concentration. high phosphate availability is known to inhibit the establishment and/or persistence of thi ...201324194742
rhizobial infection is associated with the development of peripheral vasculature in nodules of medicago truncatula.nodulation in legumes involves the coordination of epidermal infection by rhizobia with cell divisions in the underlying cortex. during nodulation, rhizobia are entrapped within curled root hairs to form an infection pocket. transcellular tubes called infection threads then develop from the pocket and become colonized by rhizobia. the infection thread grows toward the developing nodule primordia and rhizobia are taken up into the nodule cells, where they eventually fix nitrogen. the epidermal an ...201323535942
della proteins regulate arbuscule formation in arbuscular mycorrhizal symbiosis.most flowering plants are able to form endosymbioses with arbuscular mycorrhizal fungi. in this mutualistic association, the fungus colonizes the root cortex and establishes elaborately branched hyphae, called arbuscules, within the cortical cells. arbuscule development requires the cellular reorganization of both symbionts, and the resulting symbiotic interface functions in nutrient exchange. a plant symbiosis signaling pathway controls the development of the symbiosis. several components of th ...201324297892
a regulatory network-based approach dissects late maturation processes related to the acquisition of desiccation tolerance and longevity of medicago truncatula seeds.in seeds, desiccation tolerance (dt) and the ability to survive the dry state for prolonged periods of time (longevity) are two essential traits for seed quality that are consecutively acquired during maturation. using transcriptomic and metabolomic profiling together with a conditional-dependent network of global transcription interactions, we dissected the maturation events from the end of seed filling to final maturation drying during the last 3 weeks of seed development in medicago truncatul ...201323929721
genotype delimitation in the nod-independent model legume aeschynomene evenia.research on the nitrogen-fixing symbiosis has been so far focused on two model legumes, medicago truncatula and lotus japonicus, which use a sophisticated infection process involving infection thread formation. however, in 25% of the legumes, the bacterial entry occurs more simply in an intercellular fashion. among them, some semi-aquatic aeschynomene species present the distinctive feature to form nitrogen-fixing nodules on both roots and stems following elicitation by photosynthetic bradyrhizo ...201323717496
iron: an essential micronutrient for the legume-rhizobium symbiosis.legumes, which develop a symbiosis with nitrogen-fixing bacteria, have an increased demand for iron. iron is required for the synthesis of iron-containing proteins in the host, including the highly abundant leghemoglobin, and in bacteroids for nitrogenase and cytochromes of the electron transport chain. deficiencies in iron can affect initiation and development of the nodule. within root cells, iron is chelated with organic acids such as citrate and nicotianamine and distributed to other parts o ...201324062758
an endogenous artificial microrna system for unraveling the function of root endosymbioses related genes in medicago truncatula.legumes have the unique capacity to undergo two important root endosymbioses: the root nodule symbiosis and the arbuscular mycorrhizal symbiosis. medicago truncatula is widely used to unravel the functions of genes during these root symbioses. here we describe the development of an artificial microrna (amir)-mediated gene silencing system for m. truncatula roots.201323679580
regulatory patterns of a large family of defensin-like genes expressed in nodules of medicago truncatula.root nodules are the symbiotic organ of legumes that house nitrogen-fixing bacteria. many genes are specifically induced in nodules during the interactions between the host plant and symbiotic rhizobia. information regarding the regulation of expression for most of these genes is lacking. one of the largest gene families expressed in the nodules of the model legume medicago truncatula is the nodule cysteine-rich (ncr) group of defensin-like (defl) genes. we used a custom affymetrix microarray to ...201323573247
automated analysis of calcium spiking profiles with casa software: two case studies from root-microbe symbioses.repeated oscillations in intracellular calcium (ca2+) concentration, known as ca2+ spiking signals, have been described in plants for a limited number of cellular responses to biotic or abiotic stimuli and most notably the common symbiotic signaling pathway (cssp) which mediates the recognition by their plant hosts of two endosymbiotic microbes, arbuscular mycorrhizal (am) fungi and nitrogen fixing rhizobia. the detailed analysis of the complexity and variability of the ca2+ spiking patterns whi ...201324369773
the ccaat box-binding transcription factor nf-ya1 controls rhizobial infection.symbiosis between legume plants and soil rhizobia culminates in the formation of a novel root organ, the 'nodule', containing bacteria differentiated as facultative nitrogen-fixing organelles. mtnf-ya1 is a medicago truncatula ccaat box-binding transcription factor (tf), formerly called hap2-1, highly expressed in mature nodules and required for nodule meristem function and persistence. here a role for mtnf-ya1 during early nodule development is demonstrated. detailed expression analysis based o ...201324319255
the c2h2 transcription factor regulator of symbiosome differentiation represses transcription of the secretory pathway gene vamp721a and promotes symbiosome development in medicago truncatula.transcription factors (tfs) are thought to regulate many aspects of nodule and symbiosis development in legumes, although few tfs have been characterized functionally. here, we describe regulator of symbiosome differentiation (rsd) of medicago truncatula, a member of the cysteine-2/histidine-2 (c2h2) family of plant tfs that is required for normal symbiosome differentiation during nodule development. rsd is expressed in a nodule-specific manner, with maximal transcript levels in the bacterial in ...201324082011
the arabidopsis hp6 gene is expressed in medicago truncatula lateral roots and root nodule primordia.expression patterns of orthologous genes can be similar between distantly related species, suggesting that developmental programs can be conserved between organisms. here, we show that the promoter of ahp6, a gene which is involved in arabidopsis lateral root development, also drives the expression of the reporter gus gene in lateral roots of medicago truncatula suggesting that similar regulatory elements are involved in lateral root organogenesis in these species. interestingly, the ahp6 promot ...201323759550
cell- and tissue-specific transcriptome analyses of medicago truncatula root nodules.legumes have the unique ability to host nitrogen-fixing rhizobium bacteria as symbiosomes inside root nodule cells. to get insight into this key process, which forms the heart of the endosymbiosis, we isolated specific cells/tissues at different stages of symbiosome formation from nodules of the model legume medicago truncatula using laser-capture microdissection. next, we determined their associated expression profiles using affymetrix medicago genechips. cells were collected from the nodule in ...201323734198
late embryogenesis abundant (lea) proteins in legumes.plants are exposed to different external conditions that affect growth, development, and productivity. water deficit is one of these adverse conditions caused by drought, salinity, and extreme temperatures. plants have developed different responses to prevent, ameliorate or repair the damage inflicted by these stressful environments. one of these responses is the activation of a set of genes encoding a group of hydrophilic proteins that typically accumulate to high levels during seed dehydration ...201323805145
spatio-temporal expression patterns of arabidopsis thaliana and medicago truncatula defensin-like genes.plant genomes contain several hundred defensin-like (defl) genes that encode short cysteine-rich proteins resembling defensins, which are well known antimicrobial polypeptides. little is known about the expression patterns or functions of many defls because most were discovered recently and hence are not well represented on standard microarrays. we designed a custom affymetrix chip consisting of probe sets for 317 and 684 defls from arabidopsis thaliana and medicago truncatula, respectively for ...201323527067
the nodulation factor hydrolase of medicago truncatula: characterization of an enzyme specifically cleaving rhizobial nodulation signals.nodule formation induced by nitrogen-fixing rhizobia depends on bacterial nodulation factors (nfs), modified chitin oligosaccharides with a fatty acid moiety. certain nfs can be cleaved and inactivated by plant chitinases. however, the most abundant nf of sinorhizobium meliloti, an o-acetylated and sulfated tetramer, is resistant to hydrolysis by all plant chitinases tested so far. nevertheless, this nf is rapidly degraded in the host rhizosphere. here, we identify and characterize mtnfh1 (for m ...201324082029
interaction of medicago truncatula lysin motif receptor-like kinases, nfp and lyk3, produced in nicotiana benthamiana induces defence-like responses.receptor(-like) kinases with lysin motif (lysm) domains in their extracellular region play crucial roles during plant interactions with microorganisms; e.g. arabidopsis thaliana cerk1 activates innate immunity upon perception of fungal chitin/chitooligosaccharides, whereas medicago truncatula nfp and lyk3 mediate signalling upon perception of bacterial lipo-chitooligosaccharides, termed nod factors, during the establishment of mutualism with nitrogen-fixing rhizobia. however, little is still kno ...201323750228
queuosine biosynthesis is required for sinorhizobium meliloti-induced cytoskeletal modifications on hela cells and symbiosis with medicago truncatula.rhizobia are symbiotic soil bacteria able to intracellularly colonize legume nodule cells and form nitrogen-fixing symbiosomes therein. how the plant cell cytoskeleton reorganizes in response to rhizobium colonization has remained poorly understood especially because of the lack of an in vitro infection assay. here, we report on the use of the heterologous hela cell model to experimentally tackle this question. we observed that the model rhizobium sinorhizobium meliloti, and other rhizobia as we ...201323409119
the identification of novel loci required for appropriate nodule development in medicago truncatula.the formation of functional symbiotic nodules is the result of a coordinated developmental program between legumes and rhizobial bacteria. genetic analyses in legumes have been used to dissect the signaling processes required for establishing the legume-rhizobial endosymbiotic association. compared to the early events of the symbiotic interaction, less attention has been paid to plant loci required for rhizobial colonization and the functioning of the nodule. here we describe the identification ...201324119289
control of no level in rhizobium-legume root nodules: not only a plant globin story.nitric oxide (no ) is a gaseous signaling molecule which plays both regulatory and defense roles in animals and plants. in the symbiosis between legumes and rhizobia, no has been shown to be involved in bacterial infection and nodule development steps as well as in mature nodule functioning. we recently showed that an increase in no level inside medicago truncatula root nodules also could trigger premature nodule senescence. here we discuss the importance of the bacterial sinorhizobium meliloti ...201323962798
possible role of glutamine synthetase in the no signaling response in root nodules by contributing to the antioxidant defenses.nitric oxide (no) is emerging as an important regulatory player in the rhizobium-legume symbiosis. the occurrence of no during several steps of the symbiotic interaction suggests an important, but yet unknown, signaling role of this molecule for root nodule formation and functioning. the identification of the molecular targets of no is key for the assembly of the signal transduction cascade that will ultimately help to unravel no function. we have recently shown that the key nitrogen assimilator ...201324065976
host-specific nod-factors associated with medicago truncatula nodule infection differentially induce calcium influx and calcium spiking in root hairs.rhizobial nodulation (nod) factors activate both nodule morphogenesis and infection thread development during legume nodulation. nod factors induce two different calcium responses: intra-nuclear calcium oscillations and a calcium influx at the root hair tip. calcium oscillations activate nodule development; we wanted to test if the calcium influx is associated with infection. sinorhizobium meliloti nodl and nodf mutations additively reduce infection of medicago truncatula. nod-factors made by th ...201324015832
an rna sequencing transcriptome analysis reveals novel insights into molecular aspects of the nitrate impact on the nodule activity of medicago truncatula.the mechanism through which nitrate reduces the activity of legume nodules is controversial. the objective of the study was to follow medicago truncatula nodule activity after nitrate provision continuously and to identify molecular mechanisms, which down-regulate the activity of the nodules. nodule h2 evolution started to decline after about 4 h of nitrate application. at that point in time, a strong shift in nodule gene expression (rna sequencing) had occurred (1,120 differentially expressed g ...201324285852
the independent acquisition of plant root nitrogen-fixing symbiosis in fabids recruited the same genetic pathway for nodule organogenesis.only species belonging to the fabid clade, limited to four classes and ten families of angiosperms, are able to form nitrogen-fixing root nodule symbioses (rns) with soil bacteria. this concerns plants of the legume family (fabaceae) and parasponia (cannabaceae) associated with the gram-negative proteobacteria collectively called rhizobia and actinorhizal plants associated with the gram-positive actinomycetes of the genus frankia. calcium and calmodulin-dependent protein kinase (ccamk) is a key ...201323741336
small rna pathways and diversity in model legumes: lessons from genomics.small non-coding rnas (smrna) participate in the regulation of development, cell differentiation, adaptation to environmental constraints and defense responses in plants. they negatively regulate gene expression by degrading specific mrna targets, repressing their translation or modifying chromatin conformation through homologous interaction with target loci. micrornas (mirna) and short-interfering rnas (sirna) are generated from long double stranded rna (dsrna) that are cleaved into 20-24-nucle ...201323847640
genome sequence of ensifer meliloti strain wsm1022; a highly effective microsymbiont of the model legume medicago truncatula a17.ensifer meliloti wsm1022 is an aerobic, motile, gram-negative, non-spore-forming rod that can exist as a soil saprophyte or as a legume microsymbiont of medicago. wsm1022 was isolated in 1987 from a nodule recovered from the roots of the annual medicago orbicularis growing on the cyclades island of naxos in greece. wsm1022 is highly effective at fixing nitrogen with m. truncatula and other annual species such as m. tornata and m. littoralis and is also highly effective with the perennial m. sati ...201324976888
elevated co(2) modifies n acquisition of medicago truncatula by enhancing n fixation and reducing nitrate uptake from soil.the effects of elevated co2 (750 ppm vs. 390 ppm) were evaluated on nitrogen (n) acquisition and assimilation by three medicago truncatula genotypes, including two n-fixing-deficient mutants (dnf1-1 and dnf1-2) and their wild-type (jemalong). the proportion of n acquisition from atmosphere and soil were quantified by (15)n stable isotope, and n transportation and assimilation-related genes and enzymes were determined by qpcr and biochemical analysis. elevated co2 decreased nitrate uptake from so ...201324339920
candidate genes and genetic architecture of symbiotic and agronomic traits revealed by whole-genome, sequence-based association genetics in medicago truncatula.genome-wide association study (gwas) has revolutionized the search for the genetic basis of complex traits. to date, gwas have generally relied on relatively sparse sampling of nucleotide diversity, which is likely to bias results by preferentially sampling high-frequency snps not in complete linkage disequilibrium (ld) with causative snps. to avoid these limitations we conducted gwas with >6 million snps identified by sequencing the genomes of 226 accessions of the model legume medicago truncat ...201323741505
inhibition of nitrogen fixation in symbiotic medicago truncatula upon cd exposure is a local process involving leghaemoglobin.leguminous biological nitrogen fixation (bnf) is very sensitive to environmental fluctuations. it is still contentious how bnf is regulated under stress conditions. the local or systemic control of bnf and the role played by reactive oxygen species (ros) in such regulation have still not been elucidated completely. cadmium, which belongs to the so-called heavy metals, is one of the most toxic substances released into the environment. the mechanisms involved in cd toxicity are still not completel ...201324151304
single-plant, sterile microcosms for nodulation and growth of the legume plant medicago truncatula with the rhizobial symbiont sinorhizobium meliloti.rhizobial bacteria form symbiotic, nitrogen-fixing nodules on the roots of compatible host legume plants. one of the most well-developed model systems for studying these interactions is the plant medicago truncatula cv. jemalong a17 and the rhizobial bacterium sinorhizobium meliloti 1021. repeated imaging of plant roots and scoring of symbiotic phenotypes requires methods that are non-destructive to either plants or bacteria. the symbiotic phenotypes of some plant and bacterial mutants become ap ...201324121837
novel aspects of glutamine synthetase (gs) regulation revealed by a detailed expression analysis of the entire gs gene family of medicago truncatula under different physiological conditions.glutamine synthetase (gs, ec 6.3.1.2) is a central enzyme in nitrogen metabolism, and a key component of nitrogen use efficiency (nue) and plant yield and thus it is extremely important to understand how it is regulated in plants. medicago truncatula provides an excellent model system to study gs, as it contain a very simple gs gene family comprising only four expressed genes, mtgs1a and mtgs1b encoding cytosolic polypeptides, and mtgs2a and mtgs2b encoding plastid-located enzymes. to identify n ...201324053168
the involvement of medicago truncatula non-specific lipid transfer protein n5 in the control of rhizobial infection.cysteine-rich proteins seem to play important regulatory roles in medicago truncatula/sinorhizobium meliloti symbiosis. in particular, a large family of nodule-specific cysteine-rich (ncr) peptides is crucial for the differentiation of nitrogen-fixing bacteroids. the medicago truncatula n5 protein (mtn5) is currently the only reported non-specific lipid transfer protein necessary for successful rhizobial symbiosis; in addition, mtn5 shares several characteristics with ncr peptides: a small size, ...201323656864
aphanomyces euteiches cell wall fractions containing novel glucan-chitosaccharides induce defense genes and nuclear calcium oscillations in the plant host medicago truncatula.n-acetylglucosamine-based saccharides (chitosaccharides) are components of microbial cell walls and act as molecular signals during host-microbe interactions. in the legume plant medicago truncatula, the perception of lipochitooligosaccharide signals produced by symbiotic rhizobia and arbuscular mycorrhizal fungi involves the nod factor perception (nfp) lysin motif receptor-like protein and leads to the activation of the so-called common symbiotic pathway. in rice and arabidopsis, lysin motif re ...201324086432
detailed analysis of putative genes encoding small proteins in legume genomes.diverse plant genome sequencing projects coupled with powerful bioinformatics tools have facilitated massive data analysis to construct specialized databases classified according to cellular function. however, there are still a considerable number of genes encoding proteins whose function has not yet been characterized. included in this category are small proteins (sps, 30-150 amino acids) encoded by short open reading frames (sorfs). sps play important roles in plant physiology, growth, and dev ...201323802007
growth and nodulation of symbiotic medicago truncatula at different levels of phosphorus availability.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. truncatula hydroponically grown at different gradual increases in p levels. the findings revealed that m. truncatula had a narrow p regi ...201323682114
sub-cellular proteomics of medicago truncatula.medicago truncatula is a leading model species and substantial molecular, genetic, genomics, proteomics, and metabolomics resources have been developed for this species to facilitate the study of legume biology. currently, over 60 proteomics studies of m. truncatula have been published. many of these have focused upon the unique symbiosis formed between legumes and nitrogen fixing rhizobia bacteria, while others have focused on seed development and the specialized proteomes of distinct tissues/o ...201323641248
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