recombinant artificial forisomes provide ample quantities of smart biomaterials for use in technical devices.forisomes are mechanoproteins that undergo atp-independent contraction-expansion cycles triggered by divalent cations, ph changes, and electrical stimuli. although native forisomes from medicago truncatula comprise a number of subunits encoded by separate genes, here we show that at least two of those subunits (mtseo1 and mtseo4) can assemble into homomeric forisome bodies that are functionally similar to their native, multimeric counterparts. we expressed these subunits in plants and yeast, res ...201020665019
host and nonhost resistance in medicago-colletotrichum interactions.medicago truncatula lines resistant (a17) or susceptible (f83005.5) to the alfalfa pathogen colletotrichum trifolii were used to compare defense reactions induced upon inoculation with c. trifolii or with the nonadapted pathogens c. lindemuthianum and c. higginsianum. nonadapted colletotrichum spp. induced a hypersensitive response (hr)-like reaction similar to the one induced during the host-incompatible interaction. molecular analyses indicated an induction of pr10 and chalcone synthase genes ...201020687801
multiple distinct small rnas originate from the same microrna precursors.micrornas (mirnas), which originate from precursor transcripts with stem-loop structures, are essential gene expression regulators in eukaryotes.201020696037
a comparison of two class 10 pathogenesis-related genes from alfalfa and their activation by multiple stresses and stress-related signaling molecules.a collection of 29 pathogenesis-related 10 (pr10) genes of medicago sativa and medicago truncatula showed that they were almost all obtained from cdna libraries of tissues undergoing abiotic or biotic stresses. the predicted proteins could be divided into two subclasses, pr10.1 and pr10.2, but in silico predicted models of their three-dimensional structures revealed that they could be further divided based on size of the hydrophobic internal cavity and number of β-bulges. a comparison of the exp ...201020703880
the b-3 ethylene response factor mterf1-1 mediates resistance to a subset of root pathogens in medicago truncatula without adversely affecting symbiosis with rhizobia.the fungal necrotrophic pathogen rhizoctonia solani is a significant constraint to a range of crops as diverse as cereals, canola, and legumes. despite wide-ranging germplasm screens in many of these crops, no strong genetic resistance has been identified, suggesting that alternative strategies to improve resistance are required. in this study, we characterize moderate resistance to r. solani anastomosis group 8 identified in medicago truncatula. the activity of the ethylene- and jasmonate-respo ...201020713618
palmate-like pentafoliata1 encodes a novel cys(2)his(2) zinc finger transcription factor essential for compound leaf morphogenesis in medicago the primary site for photosynthetic carbon fixation and the interface between plants and the environment, plant leaves play a key role in plant growth, biomass production and survival, and global carbon and oxygen cycles. leaves can be simple with a single blade or compound with multiple units of blades known as leaflets. in a palmate-type compound leaf, leaflets are clustered at the tip of the leaf. in a pinnate-type compound leaf, on the other hand, leaflets are placed on a rachis in distan ...201020724826
[tobacco transformants expressing the medicago truncatula ornithine aminotransferase cdna].the medicago truncatula ornithine aminotransferase cdna was cloned under the potent constitutive 35s rna promoter of the cauliflower mosaic virus and transferred into the genome of tobacco nicotiana tabacum sr1 plants. transformed tobacco plants grew better in salinity stress, but did not differ in proline content under normal or stress conditions from control plants. it was assumed that the role of ornithine aminotransferase in the molecular mechanisms of stress resistance is not associated wit ...201020795505
characterization of the medicago truncatula cell wall proteome in cell suspension culture upon elicitation and suppression of plant addition to establishing methods for proteome analysis of cell wall proteins (cwps) for the model plant medicago truncatula, this work highlights the presence of several protein classes in cell culture. using a combination of two-dimensional gel electrophoresis (2d-page) and/or liquid chromatography-tandem mass spectrometry (lc-ms/ms), we established the proteome reference map of m. truncatula cell wall proteins. cwps extracted from purified cell wall fragments resulted in the identification ...201020801546
biosynthesis of udp-xylose and udp-arabinose in sinorhizobium meliloti 1021: first characterization of a bacterial udp-xylose synthase, and udp-xylose 4-epimerase.sinorhizobium meliloti is a soil bacterium that fixes nitrogen after being established inside nodules that can form on the roots of several legumes, including medicago truncatula. a mutation in an s. meliloti gene (lpsb) required for lipopolysaccharide synthesis has been reported to result in defective nodulation and an increase in the synthesis of a xylose-containing glycan. glycans containing xylose as well as arabinose are also formed by other rhizobial species, but little is known about thei ...201120847005
comparative proteomics of yeast-elicited medicago truncatula cell suspensions reveals induction of isoflavonoid biosynthesis and cell wall modifications.the temporal proteome response of medicago truncatula suspension cell cultures to yeast elicitation (which mimics fungal infection) was investigated using two-dimensional polyacrylamide gel electrophoresis (2-de) and nanoliquid chromatography coupled to tandem mass spectrometry (nano lc-ms/ms). reproducibility of 2-de was assessed using the number of the visualized protein spots and spot volume. average coefficient of variation was determined to be less than 6% for the number of spots and around ...201020853911
stimulation of defense reactions in medicago truncatula by antagonistic lipopeptides from paenibacillus sp. strain b2.with the aim of obtaining new strategies to control plant diseases, we investigated the ability of antagonistic lipopolypeptides (paenimyxin) from paenibacillus sp. strain b2 to elicit hydrogen peroxide (h₂o₂) production and several defense-related genes in the model legume medicago truncatula. for this purpose, m. truncatula cell suspensions were used and a pathosystem between m. truncatula and fusarium acuminatum was established. in m. truncatula cell cultures, the induction of h₂o₂ reached a ...201020870792
reverse genetics in medicago truncatula using tnt1 insertion mutants.medicago truncatula has been chosen as one of the two model species for legume molecular genetics and functional genomics studies. with the imminent completion of m. truncatula genome sequencing, availability of large-scale mutant populations becomes a priority. over the last 5 years, nearly 12,000 insertion lines, which represent approximately 300,000 insertions, have been generated at the samuel roberts noble foundation using the tobacco retrotransposon tnt1. individual genomic dna was isolate ...201120931380
jasmonate biosynthesis in legume and actinorhizal nodules.jasmonic acid (ja) is a plant signalling compound that has been implicated in the regulation of mutualistic symbioses. in order to understand the spatial distribution of ja biosynthetic capacity in nodules of two actinorhizal species, casaurina glauca and datisca glomerata, and one legume, medicago truncatula, we determined the localization of allene oxide cyclase (aoc) which catalyses a committed step in ja biosynthesis. in all nodule types analysed, aoc was detected exclusively in uninfected c ...201020964693
the medicago truncatula e3 ubiquitin ligase pub1 interacts with the lyk3 symbiotic receptor and negatively regulates infection and nodulation.lyk3 is a lysin motif receptor-like kinase of medicago truncatula, which is essential for the establishment of the nitrogen-fixing, root nodule symbiosis with sinorhizobium meliloti. lyk3 is a putative receptor of s. meliloti nod factor signals, but little is known of how it is regulated and how it transduces these symbiotic signals. in a screen for lyk3-interacting proteins, we identified m. truncatula plant u-box protein 1 (pub1) as an interactor of the kinase domain. in planta, both proteins ...201020971894
mtnoa1/rif1 modulates medicago truncatula-sinorhizobium meliloti nodule development without affecting its nitric oxide content.atnoa1/rif1 (formerly referred to as atnos1) has been shown to modulate nitric oxide (no) content in arabidopsis. as no generation in the legume-rhizobium symbiosis has been shown, the involvement of an atnoa1/rif1 orthologue from medicago truncatula (mtnoa1/rif1) during its symbiotic interaction with sinorhizobium meliloti has been studied. the expression of mtnoa1/rif1 appeared to occur mainly in nodule vascular bundles and the meristematic zone. using an rna interference strategy, transgenic ...201021071678
rhizoregnet-a database of rhizobial transcription factors and regulatory networks.sinorhizobium meliloti is a symbiotic soil bacterium that forms nitrogen-fixing nodules on roots of leguminous plants, including medicago truncatula (barrel medic), and m. sativa (alfalfa). the sinorhizobium-medicago symbiosis is an important symbiosis model system. knowledge gained from this system can be extended to other agriculturally important "rhizobial" symbioses. since the publication of the s. meliloti genome in 2001, many new genetic, biochemical and physiological data have been genera ...201021087643
antioxidant gene-enzyme responses in medicago truncatula genotypes with different degree of sensitivity to salinity.antioxidant responses and nodule function of medicago truncatula genotypes differing in salt tolerance were studied. salinity effects on nodules were analysed on key nitrogen fixation proteins such as nitrogenase and leghaemoglobin as well as estimating lipid peroxidation levels, and were found more dramatic in the salt-sensitive genotype. antioxidant enzyme assays for catalase (cat, ec, superoxide dismutase (ec, ascorbate peroxidase (ec and guaiacol peroxidase (ec ...201021114673
abscopal signals mediated bio-effects in low-energy ion irradiated medicago truncatula seeds.the mutagenic effects of low-energy ions have been identified by genetic studies for decades. due to the short penetration distance of ions, however, the underlying mechanism(s) is still not quite clarified. recently, increasing data have been accumulated concerning the existence and manifestation of radiation induced bystander/abscopal effects in vivo in the whole-organism environment. in this study, the bio-effects and the preliminary mechanisms of low energy ion beam irradiation on medicago t ...201021116098
functional expression and purification of cyp93c20,a plant membrane-associated cytochrome p450 from medicago truncatula.plants possess very large numbers of biosynthetic cytochrome p450 enzymes. in spite of the importance of these enzymes for the synthesis of bioactive plant secondary metabolites, only two plant p450 structures has been obtained to date. isoflavone synthase (ifs) is a membrane-associated cytochrome p450 enzyme catalyzing the entry-point reaction into isoflavonoid biosynthesis. ifs from the model legume medicago truncatula (cyp93c20) was engineered by deleting the membrane-spanning domain and inse ...201021138770
both plant and bacterial nitrate reductases contribute to nitric oxide production in medicago truncatula nitrogen-fixing nodules.nitric oxide (no) is a signaling and defense molecule of major importance in living organisms. in the model legume medicago truncatula, no production has been detected in the nitrogen fixation zone of the nodule, but the systems responsible for its synthesis are yet unknown and its role in symbiosis is far from being elucidated. in this work, using pharmacological and genetic approaches, we explored the enzymatic source of no production in m. truncatula-sinorhizobium meliloti nodules under normo ...201021139086
a medicago truncatula nadph oxidase is involved in symbiotic nodule functioning.the plant plasma membrane-localized nadph oxidases, known as respiratory burst oxidase homologues (rbohs), appear to play crucial roles in plant growth and development. they are involved in important processes, such as root hair growth, plant defence reactions and abscisic acid signalling. using sequence similarity searches, we identified seven putative rboh-encoding genes in the medicago truncatula genome. a phylogenetic reconstruction showed that rboh gene duplications occurred in legume speci ...201021155825
evidence that the exoh gene of sinorhizobium meliloti does not appear to influence symbiotic effectiveness with medicago truncatula 'jemalong a17'.the purpose of this study was to identify strains of sinorhizobium meliloti that formed either an effective or completely ineffective symbiosis with medicago truncatula l. 'jemalong a17' and, subsequently, to determine whether differences existed between their exoh genes. sinorhizobium meliloti tii7 and a5 formed an effective and ineffective symbiosis with m. truncatula 'jemalong a17', respectively. using a multilocus sequence typing method, both strains were shown to have chromosomes identical ...201021164569
fluorescent pseudomonads harboring type iii secretion genes are enriched in the mycorrhizosphere of medicago truncatula.type iii secretion systems (t3sss) of gram-negative bacteria mediate direct interactions with eukaryotic cells. pseudomonas spp. harboring t3ss genes (t3ss+) were previously shown to be more abundant in the rhizosphere than in bulk soil. to discriminate the contribution of roots and associated arbuscular mycorrhizal fungi (amf) on the enrichment of t3ss+ fluorescent pseudomonads in the rhizosphere of medicago truncatula, their frequency was assessed among pseudomonads isolated from mycorrhizal a ...201121204867
structure-function similarities between a plant receptor-like kinase and the human interleukin-1 receptor-associated kinase-4.phylogenetic analysis has previously shown that plant receptor-like kinases (rlks) are monophyletic with respect to the kinase domain and share an evolutionary origin with the animal interleukin-1 receptor-associated kinase/pelle-soluble kinases. the lysin motif domain-containing receptor-like kinase-3 (lyk3) of the legume medicago truncatula shows 33% amino acid sequence identity with human irak-4 over the kinase domain. using the structure of this animal kinase as a template, homology modeling ...201121205819
immature seeds and embryos of medicago truncatula cultured in vitro.legumes are an important source of proteins and lipids for food and feed. in addition, they are -environmentally friendly because of their capacity to fix nitrogen through a symbiosis with rhizobium that permits them to produce abundant proteins even in the absence of nitrogen fertilization. seed development in plants follows three chronological steps (1) seed coat differentiation, embryo morphogenesis and endosperm development; (2) embryo maturation with storage accumulation and (3) dehydration ...201121207260
genic snp markers and legume synteny reveal candidate genes underlying qtl for macrophomina phaseolina resistance and maturity in cowpea [vigna unguiculata (l) walp.].macrophomina phaseolina is an emerging and devastating fungal pathogen that causes significant losses in crop production under high temperatures and drought stress. an increasing number of disease incidence reports highlight the wide prevalence of the pathogen around the world and its contribution toward crop yield suppression. in cowpea [vigna unguiculata (l) walp.], limited sources of low-level host resistance have been identified, the genetic basis of which is unknown. in this study we report ...201121208448
identification of legume ropgef gene families and characterization of a medicago truncatula ropgef mediating polar growth of root hairs.root hairs play important roles in the interaction of plants with their environment. root hairs anchor the plant in the soil, facilitate nutrient uptake from the rhizosphere, and participate in symbiotic plant-microbe interactions. these specialized cells grow in a polar fashion which gives rise to their elongated shape, a process mediated in part by a family of small gtpases known as rops. ropgefs (gef, guanine nucleotide exchange factor) activate rops to effect tip growth in arabidopsis pollen ...201121223388
vapyrin, a gene essential for intracellular progression of arbuscular mycorrhizal symbiosis, is also essential for infection by rhizobia in the nodule symbiosis of medicago truncatula.intracellular invasion of root cells is required for the establishment of successful endosymbioses in legumes of both arbuscular mycorrhizal (am) fungi and rhizobial bacteria. in both interactions a requirement for successful entry is the activation of a common signalling pathway that includes five genes required to generate calcium oscillations and two genes required for the perception of the calcium response. recently, it has been discovered that in medicago truncatula, the vapyrin (vpy) gene ...201021223389
identification and characterization of thioredoxin h isoforms differentially expressed in germinating seeds of the model legume medicago truncatula.thioredoxins (trxs) h, small disulfide reductases, and nadp-thioredoxin reductases (ntrs) have been shown to accumulate in seeds of different plant species and play important roles in seed physiology. however, little is known about the identity, properties, and subcellular location of trx h isoforms that are abundant in legume seeds. to fill this gap, in this work, we characterized the trx h family of medicago truncatula, a model legume, and then explored the activity and localization of trx h i ...201121239621
transcription reprogramming during root nodule development in medicago truncatula.many genes which are associated with root nodule development and activity in the model legume medicago truncatula have been described. however information on precise stages of activation of these genes and their corresponding transcriptional regulators is often lacking. whether these regulators are shared with other plant developmental programs also remains an open question. here detailed microarray analyses have been used to study the transcriptome of root nodules induced by either wild type or ...201121304580
genetic dissection of rhizobium-induced infection and nodule organogenesis in pea based on enod12a and enod5 expression legumes, perception of rhizobial lipochitooligosacharide-based molecules (nod factors) and subsequent signal transduction triggers transcription of plant symbiosis-specific genes (early nodulins). we present genetic dissection of nod factor-controlled processes in pisum sativum using two early nodulin genes psenod12a and psenod5, that are differentially up-regulated during symbiosis. a novel set of non-nodulating pea mutants in fourteen loci was examined, among which seven loci are not descri ...201021309975
phosphorous deficiency decreases nitrogenase activity but increases proton efflux in n2-fixing medicago truncatula.effects of sinorhizobium strain and p nutrition on n(2)-dependent growth, nitrogenase activity and proton efflux by nodulated roots were investigated in the model legume medicago truncatula cultivar jemalong grown in hydroaeroponic culture in symbioses with sinorhizobium meliloti strains 102f51 and 2011. sinorhizobium strain had strong effects on nitrogenase activity and n(2)-dependent growth, with s. meliloti 102f51 being the more efficient strain. apparent and total nitrogenase activities, mea ...201121334214
interactions of arabidopsis and m. truncatula with the same pathogens differ in dependence on ethylene and ethylene response factors.microbial pathogens inflict large losses to agriculture annually and thus mechanisms of plant resistance and how to deploy them to enhance disease resistance in crops are foci of much research interest. we recently described the important role of ethylene and ethylene response transcription factors (erfs), particularly mterf1-1, in mediating resistance to the fungal pathogen rhizoctonia solani in the model legume, medicago truncatula. previous studies on the closely related aterf14, a master reg ...201121389781
leveraging genomic resources of model species for the assessment of diversity and phylogeny in wild and domesticated lentil.advances in comparative genomics have provided significant opportunities for analysis of genetic diversity in species with limited genomic resources, such as the genus lens. medicago truncatula expressed sequence tags (ests) were aligned with the arabidopsis thaliana genome sequence to identify conserved exon sequences and splice sites in the ests. conserved primers (cps) based on m. truncatula est sequences flanking one or more introns were then designed. a total of 22% of the cps produced poly ...201121454287
nitric oxide is required for an optimal establishment of the medicago truncatula-sinorhizobium meliloti symbiosis.nitric oxide (no) is a gaseous molecule that participates in numerous plant signalling pathways. it is involved in plant responses to pathogens and development processes such as seed germination, flowering and stomatal closure. using a permeable no-specific fluorescent probe and a bacterial reporter strain expressing the lacz gene under the control of a no-responsive promoter, we detected no production in the first steps, during infection threads growth, of the medicago truncatula-sinorhizobium ...201121457261
identification and characterisation of seed storage protein transcripts from lupinus legumes, seed storage proteins are important for the developing seedling and are an important source of protein for humans and animals. lupinus angustifolius (l.), also known as narrow-leaf lupin (nll) is a grain legume crop that is gaining recognition as a potential human health food as the grain is high in protein and dietary fibre, gluten-free and low in fat and starch.201121457583
mate2 mediates vacuolar sequestration of flavonoid glycosides and glycoside malonates in medicago truncatula.the majority of flavonoids, such as anthocyanins, proanthocyanidins, and isoflavones, are stored in the central vacuole, but the molecular basis of flavonoid transport is still poorly understood. here, we report the functional characterization of a multidrug and toxin extrusion transporter (mate2), from medicago truncatula. mate 2 is expressed primarily in leaves and flowers. despite its high similarity to the epicatechin 3'-o-glucoside transporter mate1, mate2 cannot efficiently transport proan ...201121467581
symbiont identity matters: carbon and phosphorus fluxes between medicago truncatula and different arbuscular mycorrhizal fungi.many studies have scrutinized the nutritional benefits of arbuscular mycorrhizal associations to their host plants, while the carbon (c) balance of the symbiosis has often been neglected. here, we present quantification of both the c costs and the phosphorus (p) uptake benefits of mycorrhizal association between barrel medic (medicago truncatula) and three arbuscular mycorrhizal fungal species, namely glomus intraradices, glomus claroideum, and gigaspora margarita. plant growth, p uptake and c a ...201121472448
generation of composite plants in medicago truncatula used for nodulation assays.similar to agrobacterium tumerfaciens, agrobacterium rhizogenes can transfer foreign dnas into plant cells based on the autonomous root-inducing (ri) plasmid. a. rhizogenes can cause hairy root formation on plant tissues and form composite plants after transformation. on these composite plants, some of the regenerated roots are transgenic, carrying the wild type t-dna and the engineered binary vector; while the shoots are still non-transgenic, serving to provide energy and growth support. these ...201121490571
crosstalk between the nodulation signaling pathway and the autoregulation of nodulation in medicago truncatula.• a subset of clavata3/endosperm-surrounding region-related (cle) peptides are involved in autoregulation of nodulation (aon) in medicago truncatula (e.g. mtcle12 and mtcle13). however, their linkage to other components of the aon pathways downstream of the shoot-derived inhibitor (sdi) is not understood. • we have ectopically expressed the putative peptide ligand encoding genes mtcle12 and mtcle13 in m. truncatula which abolished nodulation completely in wild-type roots but not in the supernodu ...201121507004
transformed hairy roots of discaria trinervis: a valuable tool for studying actinorhizal symbiosis in the context of intercellular infection.among infection mechanisms leading to root nodule symbiosis, the intercellular infection pathway is probably the most ancestral but also one of the least characterized. intercellular infection has been described in discaria trinervis, an actinorhizal plant belonging to the rosales order. to decipher the molecular mechanisms underlying intercellular infection with frankia, we set up an efficient genetic transformation protocol for d. trinervis based on a. rhizogenes. we showed that composite plan ...201121585269
transcriptome sequencing of lentil based on second-generation technology permits large-scale unigene assembly and ssr marker discovery.abstract: background: lentil (lens culinaris medik.) is a cool-season grain legume which provides a rich source of protein for human consumption. in terms of genomic resources, lentil is relatively underdeveloped, in comparison to other fabaceae species, with limited available data. there is hence a significant need to enhance such resources in order to identify novel genes and alleles for molecular breeding to increase crop productivity and quality. results: tissue-specific cdna samples from si ...201121609489
harvest-inducibility of the promoter of alfalfa s-adenosyl-l: -methionine: trans-caffeoyl-coa3-o-methyltransferase gene.a major limitation on the expression of some foreign proteins in transgenic plants is the toxic effect of such proteins on the host plant resulting in inhibition of normal growth and development. a solution to this problem is to control the expression of genes for such proteins by means of inducible promoters, as is frequently done in microbial systems. a cdna clone was obtained from subtractive hybridization of non-harvested and harvested alfalfa leaf tissue, named hi12. the hi12 cdna was ident ...201121667113
pseudonodule formation by wild type and symbiotic mutant medicago truncatula in response to auxin transport inhibitors.rhizobium and allied bacteria form symbiotic nitrogen fixing nodules on legume roots. plant hormones play key roles in nodule formation. we treated medicago truncatula roots with auxin transport inhibitors (atis) n-(1-naphthyl)phthalamic acid (npa) and 2,3,5-triiodobenzoic acid (tiba), to induce the formation of pseudonodules. m. truncatula mutants defective for rhizobial nod factor signal transduction still formed pseudonodules in response to atis. however, a m. truncatula ethylene-insensitive ...201121809981
molecular adaptation in flowering and symbiotic recognition pathways: insights from patterns of polymorphism in the legume medicago truncatula.abstract: background: we studied patterns of molecular adaptation in the wild mediterranean legume medicago truncatula. we focused on two phenotypic traits that are not functionally linked: flowering time and perception of symbiotic microbes. phenology is an important fitness component, especially for annual plants, and many instances of molecular adaptation have been reported for genes involved in flowering pathways. while perception of symbiotic microbes is also integral to adaptation in many ...201121806823
expression analysis of clavata1-like and nodulin21-like genes from pinus sylvestris during ectomycorrhiza formation.the ecology and physiology of ectomycorrhizal (ecm) symbiosis with conifer trees are well documented. in comparison, however, very little is known about the molecular regulation of these associations. in an earlier study, we identified three ecm-regulated pinus expressed sequence tags (est), two of which were identified as homologous to the medicago truncatula nodulin mtn21. the third est was a homologue to the receptor-like kinase clavata1. we have characterized the expression patterns of these ...201121751039
the exudate from an arbuscular mycorrhizal fungus induces nitric oxide accumulation in medicago truncatula roots.nitric oxide (no) is a signaling molecule involved in plant responses to abiotic and biotic stresses. while there is evidence for no accumulation during legume nodulation, almost no information exists for arbuscular mycorrhizas (am). here, we investigated the occurrence of no in the early stages of medicago truncatula-gigaspora margarita interaction, focusing on the plant response to fungal diffusible molecules. no was visualized in root organ cultures and seedlings by confocal microscopy using ...201121744141
symbiotic rhizobia bacteria trigger a change in localization and dynamics of the medicago truncatula receptor kinase form nitrogen-fixing symbioses, legume plants recognize a bacterial signal, nod factor (nf). the legume medicago truncatula has two predicted nf receptors that direct separate downstream responses to its symbiont sinorhizobium meliloti. nod factor perception encodes a putative low-stringency receptor that is responsible for calcium spiking and transcriptional responses. lysin motif receptor-like kinase3 (lyk3) encodes a putative high-stringency receptor that mediates bacterial infection. we l ...201121742993
medicago truncatula ipd3 is a member of the common symbiotic signaling pathway required for rhizobial and mycorrhizal symbioses.legumes form endosymbiotic associations with nitrogen fixing bacteria and arbuscular mycorrhizal (am) fungi which facilitate nutrient uptake. both symbiotic interactions require a molecular signal exchange between the plant and the symbiont and this involves a conserved symbiosis (sym) signaling pathway. in order to identify plant genes required for intracellular accommodation of nitrogen-fixing bacteria and am fungi, we characterized medicago truncatula symbiotic mutants defective for rhizobial ...201121692638
expression of coordinately regulated defence response genes and analysis of their role in disease resistance in medicago truncatula.microarray technology was used to identify the genes associated with disease defence responses in the model legume medicago truncatula. transcript profiles from m. truncatula cv. jemalong genotype a17 leaves inoculated with colletotrichum trifolii and erysiphe pisi and roots infected with phytophthora medicaginis were compared to identify the genes expressed in response to all three pathogens and genes unique to an interaction. the a17 genotype is resistant to c. trifolii and e. pisi, exhibiting ...201121726379
medicago truncatula cyp716a12 is a multifunctional oxidase involved in the biosynthesis of hemolytic saponins.saponins, a group of glycosidic compounds present in several plant species, have aglycone moieties that are formed using triterpenoid or steroidal skeletons. in spite of their importance as antimicrobial compounds and their possible benefits for human health, knowledge of the genetic control of saponin biosynthesis is still poorly understood. in the medicago genus, the hemolytic activity of saponins is related to the nature of their aglycone moieties. we have identified a cytochrome p450 gene (c ...201121821776
STENOFOLIA Regulates Blade Outgrowth and Leaf Vascular Patterning in Medicago truncatula and Nicotiana sylvestris.Dicot leaf primordia initiate at the flanks of the shoot apical meristem and extend laterally by cell division and cell expansion to form the flat lamina, but the molecular mechanism of lamina outgrowth remains unclear. Here, we report the identification of STENOFOLIA (STF), a WUSCHEL-like homeobox transcriptional regulator, in Medicago truncatula, which is required for blade outgrowth and leaf vascular patterning. STF belongs to the MAEWEST clade and its inactivation by the transposable element ...201121719692
strigolactone biosynthesis in medicago truncatula and rice requires the symbiotic gras-type transcription factors nsp1 and nsp2.legume gras (gai, rga, scr)-type transcription factors nodulation signaling pathway1 (nsp1) and nsp2 are essential for rhizobium nod factor-induced nodulation. both proteins are considered to be nod factor response factors regulating gene expression after symbiotic signaling. however, legume nsp1 and nsp2 can be functionally replaced by nonlegume orthologs, including rice (oryza sativa) nsp1 and nsp2, indicating that both proteins are functionally conserved in higher plants. here, we show that n ...201122039214
Recent Progress in Development of Tnt1 Functional Genomics Platform for Medicago truncatula and Lotus japonicus in Bulgaria.Legumes, as protein-rich crops, are widely used for human food, animal feed and vegetable oil production. Over the past decade, two legume species, Medicago truncatula and Lotus japonicus, have been adopted as model legumes for genomics and physiological studies. The tobacco transposable element, Tnt1, is a powerful tool for insertional mutagenesis and gene inactivation in plants. A large collection of Tnt1-tagged lines of M. truncatula cv. Jemalong was generated during the course of the project ...201121966253
CYP716A Subfamily Members are Multifunctional Oxidases in Triterpenoid Biosynthesis.Triterpenoids are a diverse group of secondary metabolites that are associated with a variety of biological activities. Oleanolic acid, ursolic acid and betulinic acid are common triterpenoids in plants with diverse biological activities, including antifungal, antibacterial, anti-human immunodeficiency virus (HIV) and/or antitumor activities. In the present study, using the gene co-expression analysis tool of Medicago truncatula, we found a strong correlation between CYP716A12 and ß-amyrin synth ...201122039103
contribution of nfp lysm domains to the recognition of nod factors during the medicago truncatula/sinorhizobium meliloti symbiosis.the root nodule nitrogen fixing symbiosis between legume plants and soil bacteria called rhizobia is of great agronomical and ecological interest since it provides the plant with fixed atmospheric nitrogen. the establishment of this symbiosis is mediated by the recognition by the host plant of lipo-chitooligosaccharides called nod factors (nfs), produced by the rhizobia. this recognition is highly specific, as precise nf structures are required depending on the host plant. here, we study the imp ...201122087221
from model to crop: functional analysis of a stay-green gene in the model legume medicago truncatula and effective use of the gene for alfalfa improvement.medicago truncatula has been developed into a model legume. its close relative alfalfa (medicago sativa) is the most widely grown forage legume crop in the united states. by screening a large population of m. truncatula mutants tagged with the transposable element of tobacco (nicotiana tabacum) cell type1 (tnt1), we identified a mutant line (nf2089) that maintained green leaves and showed green anthers, central carpels, mature pods, and seeds during senescence. genetic and molecular analyses rev ...201121957014
glutamine synthetase is a molecular target of nitric oxide in root nodules of medicago truncatula and is regulated by tyrosine nitration.nitric oxide (no) is emerging as an important regulatory player in the rhizobium-legume symbiosis, but its biological role in nodule functioning is still far from being understood. to unravel the signal transduction cascade and ultimately no function, it is necessary to identify its molecular targets. this study provides evidence that glutamine synthetase (gs), a key enzyme for root nodule metabolism, is a molecular target of no in root nodules of medicago truncatula, being regulated by tyrosine ...201121914816
protection of sinorhizobium against host cysteine-rich antimicrobial peptides is critical for symbiosis.sinorhizobium meliloti differentiates into persisting, nitrogen-fixing bacteroids within root nodules of the legume medicago truncatula. nodule-specific cysteine-rich antimicrobial peptides (ncr amps) and the bacterial baca protein are essential for bacteroid development. however, the bacterial factors central to the ncr amp response and the in planta role of baca are unknown. we investigated the hypothesis that baca is critical for the bacterial response towards ncr amps. we found that baca was ...201121990963
Analysis of the subcellular localisation of lipoxygenase in legume and actinorhizal nodules.Plant lipoxygenases (LOXs; EC catalyse the oxygenation of polyunsaturated fatty acids, linoleic (18:2) and a-linolenic acid (18:3(n-3)) and are involved in processes such as stress responses and development. Depending on the regio-specificity of a LOX, the incorporation of molecular oxygen leads to formation of 9- or 13-fatty acid hydroperoxides, which are used by LOX itself as well as by members of at least six different enzyme families to form a series of biologically active molecu ...201221973171
A phylogenetic strategy based on a legume-specific whole genome duplication yields symbiotic cytokinin type-a response regulators.Legumes host their Rhizobium spp. symbiont in novel root organs called nodules. Nodules originate from differentiated root cortical cells that dedifferentiate and subsequently form nodule primordia, a process controlled by cytokinin. A whole-genome duplication has occurred at the root of the legume Papilionoideae subfamily. We hypothesize that gene pairs originating from this duplication event and are conserved in distinct Papilionoideae lineages have evolved symbiotic functions. A phylogenetic ...201122034625
Regulation of Compound Leaf Development in Medicago truncatula by Fused Compound Leaf1, a Class M KNOX Gene.Medicago truncatula is a legume species belonging to the inverted repeat lacking clade (IRLC) with trifoliolate compound leaves. However, the regulatory mechanisms underlying development of trifoliolate leaves in legumes remain largely unknown. Here, we report isolation and characterization of fused compound leaf1 (fcl1) mutants of M. truncatula. Phenotypic analysis suggests that FCL1 plays a positive role in boundary separation and proximal-distal axis development of compound leaves. Map-based ...201122080596
Triterpene Functional Genomics in Licorice for Identification of CYP72A154 Involved in the Biosynthesis of Glycyrrhizin.Glycyrrhizin, a triterpenoid saponin derived from the underground parts of Glycyrrhiza plants (licorice), has several pharmacological activities and is also used worldwide as a natural sweetener. The biosynthesis of glycyrrhizin involves the initial cyclization of 2,3-oxidosqualene to the triterpene skeleton ß-amyrin, followed by a series of oxidative reactions at positions C-11 and C-30, and glycosyl transfers to the C-3 hydroxyl group. We previously reported the identification of a cytochrome ...201122128119
proteomic analysis by two-dimensional differential in gel electrophoresis (2d dige) of the early response of pisum sativum to orobanche crenata.crenate broomrape (orobanche crenata) is considered to be the major constraint for legume crops in mediterranean countries. strategies of control have been developed, but only marginal successes have been achieved. for the efficient control of the parasite, a better understanding of its interaction and associated resistance mechanisms at the molecular level is required. the pea response to this parasitic plant and the molecular basis of the resistance was studied using a proteomic approach based ...201221920908
phoma medicaginis stimulates the induction of the octadecanoid and phenylpropanoid pathways in medicago truncatula.gene expression changes and metabolite abundances were measured during the interaction of medicago truncatula with the fungal necrotrophic pathogen phoma medicaginis in leaf tissue of susceptible and resistant accessions. over 330 genes were differentially expressed in plants infected with p. medicaginis relative to mock-inoculated plants at 12 h post-inoculation. of these, 191 were induced in either the resistant or the susceptible accession, with 143 genes repressed. expression changes were ob ...201222212347
tnt1 retrotransposon tagging of stf in medicago truncatula reveals tight coordination of metabolic, hormonal and developmental signals during leaf morphogenesis.tnt1 (transposable element if nicotiana tabaccum cell type 1) is one of the very few active ltr retrotransposons used for gene tagging in plants. in the model legume medicago truncatula, tnt1 has been effectively used as a gene knock-out tool to generate several very useful mutants. stenofolia (stf) is such a mutant identified by tnt1 insertion in a wuschel-like homeobox transcription factor. stf is required for blade outgrowth, leaf vascular patterning and female reproductive organ development ...201122545243
structural changes in medicago truncatula root nodules caused by short-term aluminum stress.aluminum in the form of al(3+) is one of the most toxic heavy metal pollutants in nature and its effects are primarily root-related. roots of medicago truncatula exposed to 50 μm of alcl3 for 2 h and 24 h were examined by light and electron microscopy. changes in the appearance of the host cells, infection threads and bacteroidal tissue occurred during the first 2 h of al stress. microscopic observations showed that aluminum: (1) induced thickening of plant cell and infection threads (its) walls ...201223482822
movement of fluorescent dyes lucifer yellow (lych) and carboxyfluorescein (cf) in medicago truncatula gaertn. roots and root nodules.lucifer yellow (lych) and carboxyfluorescein (cf) served in medicago truncatula roots and root nodules as the markers of apoplastic and symplastic transport, respectively. the aim of this study was to understand better the water and photoassimilate translocation pathways to and within nodules. the present study shows that in damaged roots lych moves apoplastically through the vascular elements but it was not detected within the nodule vascular bundles. in intact roots, the outer cortex was stron ...201223482425
mining the phytomicrobiome to understand how bacterial coinoculations enhance plant previous work, we showed that coinoculating rhizobium leguminosarum bv. viciae 128c53 and bacillus simplex 30n-5 onto pisum sativum l. roots resulted in better nodulation and increased plant growth. we now expand this research to include another alpha-rhizobial species as well as a beta-rhizobium, burkholderia tuberum stm678. we first determined whether the rhizobia were compatible with b. simplex 30n-5 by cross-streaking experiments, and then medicago truncatula and melilotus alba were coino ...201526442090
a developmental and molecular view of formation of auxin-induced nodule-like structures in land plants.several studies have shown that plant hormones play important roles during legume-rhizobia symbiosis. for instance, auxins induce the formation of nodule-like structures (nlss) on legume roots in the absence of rhizobia. furthermore, these nls can be colonized by nitrogen-fixing bacteria, which favor nitrogen fixation compared to regular roots and subsequently increase plant yield. interestingly, auxin also induces similar nls in cereal roots. while several genetic studies have identified plant ...201627891144
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
impact of soil salinity on the structure of the bacterial endophytic community identified from the roots of caliph medic (medicago truncatula).in addition to being a forage crop, caliph medic (medicago truncatula) is also a model legume plant and is used for research focusing on the molecular characterization of the interaction between rhizobia and plants. however, the endophytic microbiome in this plant is poorly defined. endophytic bacteria play a role in supplying plants with the basic requirements necessary for growth and development. moreover, these bacteria also play a role in the mechanism of salinity stress adaptation in plants ...201627391592
differential accumulation of retroelements and diversification of nb-lrr disease resistance genes in duplicated regions following polyploidy in the ancestor of soybean.the genomes of most, if not all, flowering plants have undergone whole genome duplication events during their evolution. the impact of such polyploidy events is poorly understood, as is the fate of most duplicated genes. we sequenced an approximately 1 million-bp region in soybean (glycine max) centered on the rpg1-b disease resistance gene and compared this region with a region duplicated 10 to 14 million years ago. these two regions were also compared with homologous regions in several related ...200818842825
in medicago truncatula, water deficit modulates the transcript accumulation of components of small rna pathways.small rnas (srnas) are 20-24 nucleotide (nt) rnas and are involved in plant development and response to abiotic stresses. plants have several srna pathways implicated in the transcriptional and post-transcriptional silencing of gene expression. two key enzyme families common to all pathways are the dicer-like (dcl) proteins involved in srnas maturation and the argonautes (agos) involved in the targeting and functional action of srnas. post-transcriptional silencing mediated by agos may occur by ...201121569262
interaction between medicago truncatula and pseudomonas fluorescens: evaluation of costs and benefits across an elevated atmospheric co(2).soil microorganisms play a key role in both plants nutrition and health. their relation with plant varies from mutualism to parasitism, according to the balance of costs and benefits for the two partners of the interaction. these interactions involved the liberation of plant organic compounds via rhizodeposition. modification of atmospheric co(2) concentration may affect rhizodeposition and as a consequence trophic interactions that bind plants and microorganisms. positive effect of elevated co( ...201223029215
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
rhizotubes as a new tool for high throughput imaging of plant root development and architecture: test, comparison with pot grown plants and order to maintain high yields while saving water and preserving non-renewable resources and thus limiting the use of chemical fertilizer, it is crucial to select plants with more efficient root systems. this could be achieved through an optimization of both root architecture and root uptake ability and/or through the improvement of positive plant interactions with microorganisms in the rhizosphere. the development of devices suitable for high-throughput phenotyping of root structures remains ...201627279895
ros production during symbiotic infection suppresses pathogenesis-related gene expression.leguminous plants have exclusive ability to form symbiotic relationship with soil bacteria of the genus rhizobium. symbiosis is a complex process that involves multiple molecular signaling activities, such as calcium fluxes, production of reactive oxygen species (ros) and synthesis of nodulation genes. we analyzed the role of ros in defense gene expression in medicago truncatula during symbiosis and pathogenesis. studies in arabidopsis thaliana showed that the induction of pathogenesis-related ( ...201222499208
natural diversity in the model legume medicago truncatula allows identifying distinct genetic mechanisms conferring partial resistance to verticillium wilt.verticillium wilt is a major threat to alfalfa (medicago sativa) and many other crops. the model legume medicago truncatula was used as a host for studying resistance and susceptibility to verticillium albo-atrum. in addition to presenting well-established genetic resources, this wild plant species enables to investigate biodiversity of the response to the pathogen and putative crosstalk between disease and symbiosis. symptom scoring after root inoculation and modelling of disease curves allowed ...201223213135
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
genome-wide identification of camta gene family members in medicago truncatula and their expression during root nodule symbiosis and hormone treatments.calmodulin-binding transcription activators (camtas) are well-characterized calmodulin-binding transcription factors in the plant kingdom. previous work shows that camtas play important roles in various biological processes including disease resistance, herbivore attack response, and abiotic stress tolerance. however, studies that address the function of camtas during the establishment of symbiosis between legumes and rhizobia are still lacking. this study undertook comprehensive identification ...201526150823
naturally occurring diversity helps to reveal genes of adaptive importance in legumes.environmental changes challenge plants and drive adaptation to new conditions, suggesting that natural biodiversity may be a source of adaptive alleles acting through phenotypic plasticity and/or micro-evolution. crosses between accessions differing for a given trait have been the most common way to disentangle genetic and environmental components. interestingly, such man-made crosses may combine alleles that never meet in nature. another way to discover adaptive alleles, inspired by evolution, ...201525954294
the cre1 cytokinin pathway is differentially recruited depending on medicago truncatula root environments and negatively regulates resistance to a pathogen.cytokinins are phytohormones that regulate many developmental and environmental responses. the medicago truncatula cytokinin receptor mtcre1 (cytokinin response 1) is required for the nitrogen-fixing symbiosis with rhizobia. as several cytokinin signaling genes are modulated in roots depending on different biotic and abiotic conditions, we assessed potential involvement of this pathway in various root environmental responses. phenotyping of cre1 mutant roots infected by the gigaspora margarita a ...201525562779
mtnf-ya1, a central transcriptional regulator of symbiotic nodule development, is also a determinant of medicago truncatula susceptibility toward a root pathogen.plant nf-y transcription factors control a wide array of biological functions enabling appropriate reproductive and developmental processes as well as adaptation to various abiotic and biotic environments. in medicago truncatula, mtnf-ya1 was previously identified as a key determinant for nodule development and establishment of rhizobial symbiosis. here, we highlight a new role for this protein in compatibility to aphanomyces euteiches, a root pathogenic oomycete. the mtnf-ya1-1 mutant plants sh ...201627994614
quantitative resistance to verticillium wilt in medicago truncatula involves eradication of the fungus from roots and is associated with transcriptional responses related to innate immunity.resistance mechanisms to verticillium wilt are well-studied in tomato, cotton, and arabidopsis, but much less in legume plants. because legume plants establish nitrogen-fixing symbioses in their roots, resistance to root-attacking pathogens merits particular attention. the interaction between the soil-borne pathogen verticillium alfalfae and the model legume medicago truncatula was investigated using a resistant (a17) and a susceptible (f83005.5) line. as shown by histological analyses, coloniza ...201627746789
genome-wide identification and expression analysis of the 14-3-3 family genes in medicago truncatula.the 14-3-3 gene family, which is conserved in eukaryotes, is involved in protein-protein interactions and mediates signal transduction. however, detailed investigations of the 14-3-3 gene family in medicago truncatula are largely unknown. in this study, the identification and study of m. truncatula 14-3-3-family genes were performed based on the latest m. truncatula genome. in the m. truncatula genome, 10 14-3-3 family genes were identified, and they can be grouped into ε and non-ε groups. an ex ...201627047505
a nomadic subtelomeric disease resistance gene cluster in common bean.the b4 resistance (r) gene cluster is one of the largest clusters known in common bean (phaseolus vulgaris [pv]). it is located in a peculiar genomic environment in the subtelomeric region of the short arm of chromosome 4, adjacent to two heterochromatic blocks (knobs). we sequenced 650 kb spanning this locus and annotated 97 genes, 26 of which correspond to coiled-coil-nucleotide-binding-site-leucine-rich-repeat (cnl). conserved microsynteny was observed between the pv b4 locus and correspondin ...200919776165
stars and symbiosis: microrna- and microrna*-mediated transcript cleavage involved in arbuscular mycorrhizal symbiosis.the majority of plants are able to form the arbuscular mycorrhizal (am) symbiosis in association with am fungi. during symbiosis development, plant cells undergo a complex reprogramming resulting in profound morphological and physiological changes. micrornas (mirnas) are important components of the regulatory network of plant cells. to unravel the impact of mirnas and mirna-mediated mrna cleavage on root cell reprogramming during am symbiosis, we carried out high-throughput (illumina) sequencing ...201121571671
an overall evaluation of the resistance (r) and pathogenesis-related (pr) superfamilies in soybean, as compared with medicago and arabidopsis.plants have the ability to recognize and respond to a multitude of pathogens, resulting in a massive reprogramming of the plant to activate defense responses including resistance (r) and pathogenesis-related (pr) genes. abiotic stresses can also activate pr genes and enhance pathogen resistance, representing valuable genes for breeding purposes. the present work offers an overview of soybean r and pr genes present in the genosoja (brazilian soybean genome consortium) platform, regarding their st ...201222802711
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
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
characterization of four bifunctional plant iam/pam-amidohydrolases capable of contributing to auxin biosynthesis.amidases [ec] 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
phylogeny of plant calcium and calmodulin-dependent protein kinases (ccamks) and functional analyses of tomato ccamk in disease resistance.calcium and calmodulin-dependent protein kinase (ccamk) is a member of calcium/calmodulin-dependent protein kinase superfamily and is essential to microbe- plant symbiosis. to date, the distribution of ccamk gene in plants has not yet been completely understood, and its function in plant disease resistance remains unclear. in this study, we systemically identified the ccamk genes in genomes of 44 plant species in phytozome and analyzed the function of tomato ccamk (slccamk) in resistance to vari ...201526697034
inference of longevity-related genes from a robust coexpression network of seed maturation identifies regulators linking seed storability to biotic defense-related pathways.seed longevity, the maintenance of viability during storage, is a crucial factor for preservation of genetic resources and ensuring proper seedling establishment and high crop yield. we used a systems biology approach to identify key genes regulating the acquisition of longevity during seed maturation of medicago truncatula. using 104 transcriptomes from seed developmental time courses obtained in five growth environments, we generated a robust, stable coexpression network (matnet), thereby capt ...201526410298
transcriptomic and metabolomic analyses identify a role for chlorophyll catabolism and phytoalexin during medicago nonhost resistance against asian soybean rust.asian soybean rust (asr) caused by phakopsora pachyrhizi is a devastating foliar disease affecting soybean production worldwide. understanding nonhost resistance against asr may provide an avenue to engineer soybean to confer durable resistance against asr. we characterized a medicago truncatula-asr pathosystem to study molecular mechanisms of nonhost resistance. although urediniospores formed appressoria and penetrated into epidermal cells of m. truncatula, p. pachyrhizi failed to sporulate. tr ...201526267598
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