Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
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| soybean proteomics and its application to functional analysis. | complete genome sequences, which are available for rice and arabidopsis, provide insights into many fundamental aspects of plant biology; they do not, however, address some important aspects of legume biology. legumes are important for maintenance of human health and as crops for sustainable agriculture. two model species of legume, lotus japonicus and medicago truncatula, have been the focus of projects on genome sequencing and functional genomics. a project aimed at sequencing the genome of th ... | 2009 | 19022415 |
| y4lo of rhizobium sp. strain ngr234 is a symbiotic determinant required for symbiosome differentiation. | type 3 (t3) effector proteins, secreted by nitrogen-fixing rhizobia with a bacterial t3 secretion system, affect the nodulation of certain host legumes. the open reading frame y4lo of rhizobium sp. strain ngr234 encodes a protein with sequence similarities to t3 effectors from pathogenic bacteria (the yopj effector family). transcription studies showed that the promoter activity of y4lo depended on the transcriptional activator ttsi. recombinant y4lo protein expressed in escherichia coli did not ... | 2009 | 19060155 |
| a portal for rhizobial genomes: rhizogate integrates a sinorhizobium meliloti genome annotation update with postgenome data. | sinorhizobium meliloti is a symbiotic soil bacterium of the alphaproteobacterial subdivision. like other rhizobia, s. meliloti induces nitrogen-fixing root nodules on leguminous plants. this is an ecologically and economically important interaction, because plants engaged in symbiosis with rhizobia can grow without exogenous nitrogen fertilizers. the s. meliloti-medicago truncatula (barrel medic) association is an important symbiosis model. the s. meliloti genome was published in 2001, and the m ... | 2009 | 19103235 |
| stabilizing mechanisms in a legume-rhizobium mutualism. | preferential rewarding of more beneficial partners may stabilize mutualisms against the invasion of less beneficial, that is cheater, genotypes. recent evidence suggests that both partner choice and sanctioning may play roles in preventing the invasion of less-beneficial rhizobia in legume-rhizobium mutualisms. the importance of these mechanisms in natural communities, however, remains unclear. we grew 12 medicago truncatula maternal families with a mixture of three rhizobium strains from their ... | 2009 | 19087187 |
| aer1, a major gene conferring resistance to aphanomyces euteiches in medicago truncatula. | aphanomyces euteiches is a major soilborne oomycete pathogen that infects various legume species, including pea and alfalfa. the model legume medicago truncatula has recently emerged as a valuable genetic system for understanding the genetic basis of resistance to a. euteiches in leguminous crops. the objective of this study was to identify genetic determinants of resistance to a broad host-range pea-infecting strain of a. euteiches in m. truncatula. two m. truncatula segregating populations of ... | 2009 | 19159312 |
| an ste12 gene identified in the mycorrhizal fungus glomus intraradices restores infectivity of a hemibiotrophic plant pathogen. | mechanisms of root penetration by arbuscular mycorrhizal (am) fungi are unknown and investigations are hampered by the lack of transformation systems for these unculturable obligate biotrophs. early steps of host infection by hemibiotrophic fungal phytopathogens, sharing common features with those of am fungal colonization, depend on the transcription factor ste12. using degenerated primers and rapid amplification of cdna ends, we isolated the full-length cdna of an ste12-like gene, gintste, fro ... | 2009 | 19140944 |
| effects of indole-3-acetic acid on sinorhizobium meliloti survival and on symbiotic nitrogen fixation and stem dry weight production. | we evaluated the effects of the main auxin phytohormone, indole-3-acetic acid (iaa), on the central metabolism of sinorhizobium meliloti 1021. we either treated s. meliloti 1021 wild-type cells with 0.5 mm iaa, 1021+, or use a derivative, rd64, of the same strain harboring an additional pathway for iaa biosynthesis (converting tryptophan into iaa via indoleacetamide). we assayed the activity of tricarboxylic acid cycle (tca) key enzymes and found that activity of citrate synthase and alpha-ketog ... | 2009 | 19343341 |
| the lap1 myb transcription factor orchestrates anthocyanidin biosynthesis and glycosylation in medicago. | myb transcription factors help to control anthocyanin biosynthesis in plants, and ectopic expression of the arabidopsis production of anthocyanin pigment 1 (pap1) transcription factor activates the anthocyanin pathway in tobacco, suggesting the general utility of such factors for metabolic engineering of anthocyanins and anthocyanin-derived compounds such as proanthocyanidins (condensed tannins). however, pap1 does not activate anthocyanin biosynthesis in the model legume medicago truncatula or ... | 2009 | 19368693 |
| gras proteins form a dna binding complex to induce gene expression during nodulation signaling in medicago truncatula. | the symbiotic association of legumes with rhizobia involves bacterially derived nod factor, which is sufficient to activate the formation of nodules on the roots of the host plant. perception of nod factor by root hair cells induces calcium oscillations that are a component of the nod factor signal transduction pathway. perception of the calcium oscillations is a function of a calcium- and calmodulin-dependent protein kinase, and this activates nodulation gene expression via two gras domain tran ... | 2009 | 19252081 |
| differing requirements for flavonoids during the formation of lateral roots, nodules and root knot nematode galls in medicago truncatula. | * in this study, we tested whether the organogenesis of symbiotic root nodules, lateral roots and root galls induced by parasitic root knot nematodes (meloidogyne javanica) was regulated by the presence of flavonoids in the roots of medicago truncatula. flavonoids accumulate in all three types of root organ, and have been hypothesized previously to be required for secondary root organogenesis because of their potential role as auxin transport regulators. * using rna interference to silence the f ... | 2009 | 19402878 |
| gene expression analysis of molecular mechanisms of defense induced in medicago truncatula parasitized by orobanche crenata. | the infection of medicago truncatula gaertn. roots with the obligate parasite orobanche crenata forsk. is a useful model for studying the molecular events involved in the legumes-parasite interaction. in order to gain insight into the identification of gene-regulatory elements involved in the resistance mechanism, the temporal expression pattern of ten defense-related genes was carried out using real-time quantitative reverse-transcription polymerase chain reaction assays. the induction of all o ... | 2009 | 19321356 |
| transcriptome analysis of a bacterially induced basal and hypersensitive response of medicago truncatula. | research using the well-studied model legume medicago truncatula has largely focused on rhizobium symbiosis, while little information is currently available for this species on pathogen-induced transcriptome changes. we have performed a transcriptome analysis of this species with the objective of studying the basal (br, no visible symptoms) and hypersensitive response (hr, plant cell death) in its leaves at 6 and at 24 h after infection by hr-negative (hrcc mutant) and hr-inducing pseudomonas sy ... | 2009 | 19466566 |
| dissection of bacterial wilt on medicago truncatula revealed two type iii secretion system effectors acting on root infection process and disease development. | ralstonia solanacearum is the causal agent of the devastating bacterial wilt disease, which colonizes susceptible medicago truncatula via the intact root tip. infection involves four steps: appearance of root tip symptoms, root tip cortical cell invasion, vessel colonization, and foliar wilting. we examined this pathosystem by in vitro inoculation of intact roots of susceptible or resistant m. truncatula with the pathogenic strain gmi1000. the infection process was type iii secretion system depe ... | 2009 | 19493968 |
| changes in the profile of flavonoid accumulation in medicago truncatula leaves during infection with fungal pathogen phoma medicaginis. | medicago truncatula is a model species for the study of the unique secondary metabolism in legumes. lc/ms/ms analysis was used to identify and profile flavonoid glycoconjugates and free aglycones in leaves of m. truncatula (ecotype r108-1) infected with the fungal pathogen phoma medicaginis. use of a high resolution analyzer with a collision induced dissociation tandem mass spectrometer (cid ms/ms) permitted structural elucidation of target secondary metabolites and four new acylated flavone gly ... | 2009 | 19541494 |
| integrated metabolite and transcript profiling identify a biosynthetic mechanism for hispidol in medicago truncatula cell cultures. | metabolic profiling of elicited barrel medic (medicago truncatula) cell cultures using high-performance liquid chromatography coupled to photodiode and mass spectrometry detection revealed the accumulation of the aurone hispidol (6-hydroxy-2-[(4-hydroxyphenyl)methylidene]-1-benzofuran-3-one) as a major response to yeast elicitor. parallel, large-scale transcriptome profiling indicated that three peroxidases, mtprx1, mtprx2, and mtprx3, were coordinately induced with the accumulation of hispidol. ... | 2009 | 19571306 |
| stimulation of nodulation in medicago truncatula by low concentrations of ammonium: quantitative reverse transcription pcr analysis of selected genes. | although mineral nitrogen generally has negative effects on nodulation in legume-rhizobia symbioses, low concentrations of ammonium stimulate nodulation in some legumes. in this study, the effects of ammonium and nitrate on growth, nodulation and expression of 2 nitrogen transport and 12 putative nodulation-related genes of the model symbiosis of medicago truncatula - sinorhizobium meliloti are investigated. after 3 weeks of hydroponic growth, whole-plant nodulation was enhanced in all the ammon ... | 2009 | 19140888 |
| medicago truncatula (e)-beta-ocimene synthase is induced by insect herbivory with corresponding increases in emission of volatile ocimene. | virtually all plants are able to recognize attack by herbivorous insects and release volatile organic compounds (voc) in response. terpenes are the most abundant and varied class of insect-induced voc from plants. four genes encoding putative terpene synthases (mttps1, mttps2, mttps3 and mttps4) were shown to accumulate in medicago truncatula gaertn. in response to spodoptera exigua (hübner) feeding and methyl jasmonate treatment in a previous study [s.k. gomez, m.m. cox, j.c. bede, k.k. inoue, ... | 2009 | 19249223 |
| identification of qtl affecting seed mineral concentrations and content in the model legume medicago truncatula. | increasing the amount of bioavailable micronutrients such as iron and zinc in plant foods for human consumption is an international goal, intended especially for developing countries where micronutrient deficiencies are an ongoing health risk. legume seeds have the potential to provide the essential nutrients required by humans, but concentrations of several minerals are low when compared to other foods. in order to increase seed mineral concentrations, it is important to understand the genes an ... | 2009 | 19396421 |
| metabolic capacity of sinorhizobium (ensifer) meliloti strains as determined by phenotype microarray analysis. | sinorhizobium meliloti is a soil bacterium that fixes atmospheric nitrogen in plant roots. the high genetic diversity of its natural populations has been the subject of extensive analysis. recent genomic studies of several isolates revealed a high content of variable genes, suggesting a correspondingly large phenotypic differentiation among strains of s. meliloti. here, using the phenotype microarray (pm) system, hundreds of different growth conditions were tested in order to compare the metabol ... | 2009 | 19561177 |
| annexins - calcium- and membrane-binding proteins in the plant kingdom: potential role in nodulation and mycorrhization in medicago truncatula. | annexins belong to a family of multi-functional membrane- and ca(2+)-binding proteins. the characteristic feature of these proteins is that they can bind membrane phospholipids in a reversible, ca(2+)-dependent manner. while animal annexins have been known for a long time and are fairly well characterized, their plant counterparts were discovered only in 1989, in tomato, and have not been thoroughly studied yet. in the present review, we discuss the available information about plant annexins wit ... | 2009 | 19421430 |
| medicago truncatula improves salt tolerance when nodulated by an indole-3-acetic acid-overproducing sinorhizobium meliloti strain. | the abiotic stress resistance of wild-type sinorhizobium meliloti 1021 was compared with that of rd64, a derivative of the 1021 strain harbouring an additional pathway for the synthesis of indole-3-acetic acid (iaa), expressed in both free-living bacteria and bacteroids. it is shown here that the iaa-overproducing rd64 strain accumulated a higher level of trehalose as its endogenous osmolyte and showed an increased tolerance to several stress conditions (55 degrees c, 4 degrees c, uv-irradiation ... | 2009 | 19436044 |
| composite medicago truncatula plants harbouring agrobacterium rhizogenes-transformed roots reveal normal mycorrhization by glomus intraradices. | composite plants consisting of a wild-type shoot and a transgenic root are frequently used for functional genomics in legume research. although transformation of roots using agrobacterium rhizogenes leads to morphologically normal roots, the question arises as to whether such roots interact with arbuscular mycorrhizal (am) fungi in the same way as wild-type roots. to address this question, roots transformed with a vector containing the fluorescence marker dsred were used to analyse am in terms o ... | 2009 | 19574251 |
| (homo)glutathione depletion modulates host gene expression during the symbiotic interaction between medicago truncatula and sinorhizobium meliloti. | under nitrogen-limiting conditions, legumes interact with symbiotic rhizobia to produce nitrogen-fixing root nodules. we have previously shown that glutathione and homoglutathione [(h)gsh] deficiencies impaired medicago truncatula symbiosis efficiency, showing the importance of the low m(r) thiols during the nodulation process in the model legume m. truncatula. in this study, the plant transcriptomic response to sinorhizobium meliloti infection under (h)gsh depletion was investigated using cdna- ... | 2009 | 19587096 |
| differential expression proteomics to investigate responses and resistance to orobanche crenata in medicago truncatula. | parasitic angiosperm orobanche crenata infection represents a major constraint for the cultivation of legumes worldwide. the level of protection achieved to date is either incomplete or ephemeral. hence, an efficient control of the parasite requires a better understanding of its interaction and associated resistance mechanisms at molecular levels. | 2009 | 19575787 |
| partial resistance of medicago truncatula to aphanomyces euteiches is associated with protection of the root stele and is controlled by a major qtl rich in proteasome-related genes. | a pathosystem between aphanomyces euteiches, the causal agent of pea root rot disease, and the model legume medicago truncatula was developed to gain insights into mechanisms involved in resistance to this oomycete. the f83005.5 french accession and the a17-jemalong reference line, susceptible and partially resistant, respectively, to a. euteiches, were selected for further cytological and genetic analyses. microscopy analyses of thin root sections revealed that a major difference between the tw ... | 2009 | 19656040 |
| symbiotic diversity of ensifer meliloti strains recovered from various legume species in tunisia. | ensifer meliloti (formerly sinorhizobium meliloti) was first considered as a specific microsymbiont of medicago, melilotus and trigonella. however, strains of e. meliloti were recovered from root nodules of various legume species and their symbiotic status still remains unclear. here, we further investigate the specificity of these strains. a collection of 47 e. meliloti strains isolated in tunisia from root nodules of medicago truncatula, medicago sativa, medicago ciliaris, medicago laciniata, ... | 2009 | 19665858 |
| mate transporters facilitate vacuolar uptake of epicatechin 3'-o-glucoside for proanthocyanidin biosynthesis in medicago truncatula and arabidopsis. | expression of the arabidopsis thaliana myb transcription factor transparent testa 2 (tt2) in medicago trunculata hairy roots induces both proanthocyanidin accumulation and the atp-dependent vacuolar/vesicular uptake of epicatechin 3'-o-glucoside; neither process is active in control roots that do, however, possess anthocyanidin 3-o-glucoside vacuolar uptake activity. a vacuolar membrane-localized multidrug and toxic compound extrusion (mate) transporter, medicago mate1, was identified at the mol ... | 2009 | 19684242 |
| a nuclear-targeted cameleon demonstrates intranuclear ca2+ spiking in medicago truncatula root hairs in response to rhizobial nodulation factors. | lipochitooligosaccharide nodulation factors (nfs) secreted by endosymbiotic nitrogen-fixing rhizobia trigger ca(2+) spiking in the cytoplasmic perinuclear region of host legume root hairs. to determine whether nfs also elicit ca(2+) responses within the plant cell nucleus we have made use of a nucleoplasmin-tagged cameleon (nupyc2.1). confocal microscopy using this nuclear-specific calcium reporter has revealed sustained and regular ca(2+) spiking within the nuclear compartment of medicago trunc ... | 2009 | 19700563 |
| can differences of nitrogen nutrition level among medicago truncatula genotypes be assessed non-destructively?: probing with a recombinant inbred lines population. | the international consensus on medicago truncatula as a model system has lead to the development of powerful approaches for dissecting the genetic and molecular bases of legume nitrogen nutrition. however, such approaches now come up against a poor knowledge of the phenotypic traits that should be used for the large-scale screening of the genotypic variability associated with nitrogen nutrition. this issue was unravelled in a previous report, in which an ecophysiological approach allowed a bette ... | 2009 | 19704700 |
| knockdown of cell division cycle16 reveals an inverse relationship between lateral root and nodule numbers and a link to auxin in medicago truncatula. | the postembryonic development of lateral roots and nodules is a highly regulated process. recent studies suggest the existence of cross talk and interdependency in the growth of these two organs. although plant hormones, including auxin and cytokinin, appear to be key players in coordinating this cross talk, very few genes that cross-regulate root and nodule development have been uncovered so far. this study reports that a homolog of cell division cycle16 (cdc16), a core component of the anaphas ... | 2009 | 19789288 |
| live-cell imaging reveals periarbuscular membrane domains and organelle location in medicago truncatula roots during arbuscular mycorrhizal symbiosis. | in the arbuscular mycorrhizal symbiosis, the fungal symbiont colonizes root cortical cells, where it establishes differentiated hyphae called arbuscules. as each arbuscule develops, the cortical cell undergoes a transient reorganization and envelops the arbuscule in a novel symbiosis-specific membrane, called the periarbuscular membrane. the periarbuscular membrane, which is continuous with the plant plasma membrane of the cortical cell, is a key interface in the symbiosis; however, relatively l ... | 2009 | 19692536 |
| a novel plant leucine-rich repeat receptor kinase regulates the response of medicago truncatula roots to salt stress. | in plants, a diverse group of cell surface receptor-like protein kinases (rlks) plays a fundamental role in sensing external signals to regulate gene expression. roots explore the soil environment to optimize their growth via complex signaling cascades, mainly analyzed in arabidopsis thaliana. however, legume roots have significant physiological differences, notably their capacity to establish symbiotic interactions. these major agricultural crops are affected by environmental stresses such as s ... | 2009 | 19244136 |
| lin, a novel type of u-box/wd40 protein, controls early infection by rhizobia in legumes. | the formation of a nitrogen-fixing nodule requires the coordinated development of rhizobial colonization and nodule organogenesis. based on its mutant phenotype, lumpy infections (lin), lin functions at an early stage of the rhizobial symbiotic process, required for both infection thread growth in root hair cells and the further development of nodule primordia. we show that spontaneous nodulation activated by the calcium- and calmodulin-dependent protein kinase is independent of lin; thus, lin i ... | 2009 | 19776163 |
| the association of homeobox gene expression with stem cell formation and morphogenesis in cultured medicago truncatula. | somatic embryogenesis (se) is induced in vitro in medicago truncatula 2ha by auxin and cytokinin but rarely in wild type jemalong. the putative wuschel (mtwus), clavata3 (mtclv3) and the wuschel-related homeobox gene wox5 (mtwox5) were investigated in m. truncatula (mt) and identified by the similarity to arabidopsis wus, clv3 and wox5 in amino acid sequence, phylogeny and in planta and in vitro expression patterns. mtwus was induced throughout embryogenic cultures by cytokinin after 24-48 h and ... | 2009 | 19639337 |
| expression of the somatic embryogenesis receptor-like kinase1 (serk1) gene is associated with developmental change in the life cycle of the model legume medicago truncatula. | somatic embryogenesis receptor-like kinase (serk) genes have been demonstrated to play a role in somatic embryogenesis in several plant species. as more is learnt about these genes, the view of their role in plant development has broadened. the medicago truncatula mtserk1 gene has been associated with somatic embryogenesis and in vitro root formation. in order to study the role of mtserk1 in development further, the mtserk1 promoter sequence has been isolated and cloned into a promoter-gus analy ... | 2009 | 19305022 |
| medicago truncatula and glomus intraradices gene expression in cortical cells harboring arbuscules in the arbuscular mycorrhizal symbiosis. | most vascular flowering plants have the capacity to form symbiotic associations with arbuscular mycorrhizal (am) fungi. the symbiosis develops in the roots where am fungi colonize the root cortex and form arbuscules within the cortical cells. arbuscules are enveloped in a novel plant membrane and their establishment requires the coordinated cellular activities of both symbiotic partners. the arbuscule-cortical cell interface is the primary functional interface of the symbiosis and is of central ... | 2009 | 19161626 |
| antiquity and function of castor and pollux, the twin ion channel-encoding genes key to the evolution of root symbioses in plants. | root symbioses with arbuscular mycorrhizal fungi and rhizobial bacteria share a common signaling pathway in legumes. among the common symbiosis genes are castor and pollux, the twin homologous genes in lotus japonicus that encode putative ion channel proteins. here, we show that the orthologs of castor and pollux are ubiquitously present and highly conserved in both legumes and nonlegumes. using rice (oryza sativa) as a study system, we employ reverse genetic tools (knockout mutants and rna inte ... | 2009 | 18978069 |
| mere1, a low-copy-number copia-type retroelement in medicago truncatula active during tissue culture. | we have identified an active medicago truncatula copia-like retroelement called medicago retroelement1-1 (mere1-1) as an insertion in the symbiotic nsp2 gene. mere1-1 belongs to a low-copy-number family in the sequenced medicago genome. these copies are highly related, but only three of them have a complete coding region and polymorphism exists between the long terminal repeats of these different copies. this retroelement family is present in all m. truncatula ecotypes tested but also in other l ... | 2009 | 19656907 |
| a wd40 repeat protein from medicago truncatula is necessary for tissue-specific anthocyanin and proanthocyanidin biosynthesis but not for trichome development. | wd40 repeat proteins regulate biosynthesis of anthocyanins, proanthocyanidins (pas), and mucilage in the seed and the development of trichomes and root hairs. we have cloned and characterized a wd40 repeat protein gene from medicago truncatula (mtwd40-1) via a retrotransposon-tagging approach. deficiency of mtwd40-1 expression blocks accumulation of mucilage and a range of phenolic compounds, including pas, epicatechin, other flavonoids, and benzoic acids, in the seed, reduces epicatechin levels ... | 2009 | 19710231 |
| 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 ... | 2009 | 19776165 |
| biotic and abiotic stimulation of root epidermal cells reveals common and specific responses to arbuscular mycorrhizal fungi. | during arbuscular mycorrhizal (am) colonization, a focal accumulation of organelles occurs in root epidermal cells, prior to fungal penetration, beneath adhering hyphopodia. this is followed by the appearance of the prepenetration apparatus (ppa), a transcellular column of cytoplasm connected to the nucleus and rich in cytoskeleton and secretory endomembranes. this apparatus appears to be responsible for the construction of an apoplastic compartment that confines the fungus within the cell lumen ... | 2009 | 19151131 |
| the use of neutral and non-neutral ssrs to analyse the genetic structure of a tunisian collection of medicago truncatula lines and to reveal associations with eco-environmental variables. | in this study, we investigated the genetic diversity of a collection of 136 medicago truncatula lines from 10 tunisian natural populations collected in well-defined locations and in various ecological conditions of soil, salinity and water availability. the genetic diversity was evaluated using a set of 18 microsatellites (ssrs), representing the 8 chromosomes of m. truncatula. a neutrality test showed that 7 ssrs were non-neutral with evidence of balancing selection. the 11 neutral ssrs reveale ... | 2009 | 18704697 |
| flavones and flavonols play distinct critical roles during nodulation of medicago truncatula by sinorhizobium meliloti. | flavonoids play critical roles in legume-rhizobium symbiosis. however, the role of individual flavonoid compounds in this process has not yet been clearly established. we silenced different flavonoid-biosynthesis enzymes to generate transgenic medicago truncatula roots with different flavonoid profiles. silencing of chalcone synthase, the key entry-point enzyme for flavonoid biosynthesis led to flavonoid-deficient roots. silencing of isoflavone synthase and flavone synthase led to roots deficien ... | 2009 | 18786000 |
| bacterial effects on arbuscular mycorrhizal fungi and mycorrhiza development as influenced by the bacteria, fungi, and host plant. | bacterial strains from mycorrhizal roots (three belonging to comamonadaceae and one to oxalobacteraceae) and from non-mycorrhizal roots (two belonging to comamonadaceae) of medicago truncatula and two reference strains (collimonas fungivorans ter331 and pseudomonas fluorescens c7r12) were tested for their effect on the in vitro saprophytic growth of glomus mosseae beg12 and on its colonization of m. truncatula roots. only the oxalobacteraceae strain, isolated from barrel medic mycorrhizal roots, ... | 2009 | 18941805 |
| imaging phosphatidylinositol 4-phosphate dynamics in living plant cells. | polyphosphoinositides represent a minor group of phospholipids, accounting for less than 1% of the total. despite their low abundance, these molecules have been implicated in various signalling and membrane trafficking events. phosphatidylinositol 4-phosphate (ptdins4p) is the most abundant polyphosphoinositide. (32)pi-labelling studies have shown that the turnover of ptdins4p is rapid, but little is known about where in the cell or plant this occurs. here, we describe the use of a lipid biosens ... | 2009 | 18785997 |
| a single gene, ain, in medicago truncatula mediates a hypersensitive response to both bluegreen aphid and pea aphid, but confers resistance only to bluegreen aphid. | biotic stress in plants frequently induces a hypersensitive response (hr). this distinctive reaction has been studied intensively in several pathosystems and has shed light on the biology of defence signalling. compared with microbial pathogens, relatively little is known about the role of the hr in defence against insects. reference genotype a17 of medicago truncatula gaertn., a model legume, responds to aphids of the genus acyrthosiphon with necrotic lesions resembling a hr. in this study, the ... | 2009 | 19690018 |
| two independent resistance genes in the medicago truncatula cultivar jester confer resistance to two different aphid species of the genus acyrthosiphon. | 2009 | 19794854 | |
| genomic inventory and transcriptional analysis of medicago truncatula transporters. | transporters move hydrophilic substrates across hydrophobic biological membranes and play key roles in plant nutrition, metabolism, and signaling and, consequently, in plant growth, development, and responses to the environment. to initiate and support systematic characterization of transporters in the model legume medicago truncatula, we identified 3,830 transporters and classified 2,673 of these into 113 families and 146 subfamilies. analysis of gene expression data for 2,611 of these transpor ... | 2009 | 20023147 |
| truncatulix--a data warehouse for the legume community. | databases for either sequence, annotation, or microarray experiments data are extremely beneficial to the research community, as they centrally gather information from experiments performed by different scientists. however, data from different sources develop their full capacities only when combined. the idea of a data warehouse directly adresses this problem and solves it by integrating all required data into one single database - hence there are already many data warehouses available to geneti ... | 2009 | 19210766 |
| genome-wide medicago truncatula small rna analysis revealed novel micrornas and isoforms differentially regulated in roots and nodules. | posttranscriptional regulation of a variety of mrnas by small 21- to 24-nucleotide rnas, notably the micrornas (mirnas), is emerging as a novel developmental mechanism. in legumes like the model medicago truncatula, roots are able to develop a de novo meristem through the symbiotic interaction with nitrogen-fixing rhizobia. we used deep sequencing of small rnas from root apexes and nodules of m. truncatula to identify 100 novel candidate mirnas encoded by 265 hairpin precursors. new atypical pre ... | 2009 | 19767456 |
| [cloning and characterization of open reading frame encoding beta-amyrin synthase in glycyrrhiza uralensis]. | to clone and sequence the open reading frame of beta-amyrin synthase (bas) from glycyrrhiza uralensis. | 2009 | 20067007 |
| dynamic rearrangements determine genome organization and useful traits in soybean. | soybean (glycine max) is a paleopolyploid whose genome has gone through at least two rounds of polyploidy and subsequent diploidization events. several studies have investigated the changes in genome structure produced by the relatively recent polyploidy event, but little is known about the ancient polyploidy due to the high frequency of gene loss after duplication. our previous study, regarding a region responsible for bacterial leaf pustule, reported two homeologous rxp regions produced by the ... | 2009 | 19684227 |
| plantsups: a database of plants' ubiquitin proteasome system. | the ubiquitin 26s/proteasome system (ups), a serial cascade process of protein ubiquitination and degradation, is the last step for most cellular proteins. there are many genes involved in this system, but are not identified in many species. the accumulating availability of genomic sequence data is generating more demands in data management and analysis. genomics data of plants such as populus trichocarpa, medicago truncatula, glycine max and others are now publicly accessible. it is time to int ... | 2009 | 19445698 |
| establishment of a soybean (glycine max merr. l) transposon-based mutagenesis repository. | soybean is a major crop species providing valuable feedstock for food, feed and biofuel. in recent years, considerable progress has been made in developing genomic resources for soybean, including on-going efforts to sequence the genome. these efforts have identified a large number of soybean genes, most with unknown function. therefore, a major research priority is determining the function of these genes, especially those involved in agronomic performance and seed traits. one means to study gen ... | 2009 | 18855007 |
| a consensus genetic map of cowpea [vigna unguiculata (l) walp.] and synteny based on est-derived snps. | consensus genetic linkage maps provide a genomic framework for quantitative trait loci identification, map-based cloning, assessment of genetic diversity, association mapping, and applied breeding in marker-assisted selection schemes. among "orphan crops" with limited genomic resources such as cowpea [vigna unguiculata (l.) walp.] (2n = 2x = 22), the use of transcript-derived snps in genetic maps provides opportunities for automated genotyping and estimation of genome structure based on synteny ... | 2009 | 19826088 |
| the signal peptide of the medicago truncatula modular nodulin mtnod25 operates as an address label for the specific targeting of proteins to nitrogen-fixing symbiosomes. | the nodule-specific mtnod25 gene of the model legume medicago truncatula encodes a modular nodulin composed of different repetitive modules flanked by distinct n- and c-termini. although similarities are low with respect to all repetitive modules, both the n-terminal signal peptide (sp) and the c-terminus are highly conserved in modular nodulins from different legumes. on the cellular level, mtnod25 is only transcribed in the infected cells of root nodules, and this activation is mediated by a 2 ... | 2009 | 19061403 |
| a linkage map for the b-genome of arachis (fabaceae) and its synteny to the a-genome. | arachis hypogaea (peanut) is an important crop worldwide, being mostly used for edible oil production, direct consumption and animal feed. cultivated peanut is an allotetraploid species with two different genome components, a and b. genetic linkage maps can greatly assist molecular breeding and genomic studies. however, the development of linkage maps for a. hypogaea is difficult because it has very low levels of polymorphism. this can be overcome by the utilization of wild species of arachis, w ... | 2009 | 19351409 |
| dominance induction of fruitlet shedding in malus x domestica (l. borkh): molecular changes associated with polar auxin transport. | apple fruitlet abscission is induced by dominance, a process in which hormones such as auxin, cytokinins and strigolactone play a pivotal role. the response to these hormones is controlled by transcription regulators such as aux/iaa and arr, whereas auxin transport is controlled by influx and efflux carriers. | 2009 | 19941659 |
| full-size abc transporters from the abcg subfamily in medicago truncatula. | full-size atp-binding cassette (abc) transporters belonging to the abcg subfamily are unique for plants and fungi. there is growing evidence that certain of these proteins play a role in plant defense or signaling systems. as yet, a complete set of full-size abcg protein genes has been inventoried and classified in only two plants: arabidopsis thaliana and oryza sativa. recently, a domain-based clustering analysis has predicted the presence of at least 12 genes encoding such proteins in the lotu ... | 2009 | 19589068 |
| microcollinearity in an ethylene receptor coding gene region of the coffea canephora genome is extensively conserved with vitis vinifera and other distant dicotyledonous sequenced genomes. | coffea canephora, also called robusta, belongs to the rubiaceae, the fourth largest angiosperm family. this diploid species (2x = 2n = 22) has a fairly small genome size of approximately 690 mb and despite its extreme economic importance, particularly for developing countries, knowledge on the genome composition, structure and evolution remain very limited. here, we report the 160 kb of the first c. canephora bacterial artificial chromosome (bac) clone ever sequenced and its fine analysis. | 2009 | 19243618 |
| transcriptional regulation and signaling in phosphorus starvation: what about legumes? | the availability of soil phosphorus (p), an essential element, is one of the most important requirements for plant growth and crop production. the morphological and physiological adaptations evolved by plants to cope with p starvation have been well characterized. several p deficiency plant responses are regulated at the transcriptional level. microarray analysis has generated valuable information on global gene expression in arabidopsis thaliana grown under p-stress. despite the identification ... | 2008 | 19017108 |
| gfp tagging of sieve element occlusion (seo) proteins results in green fluorescent forisomes. | forisomes are ca(2+)-driven, atp-independent contractile protein bodies that reversibly occlude sieve elements in faboid legumes. they apparently consist of at least three proteins; potential candidates have been described previously as 'for' proteins. we isolated three genes from medicago truncatula that correspond to the putative forisome proteins and expressed their green fluorescent protein (gfp) fusion products in vicia faba and glycine max using the composite plant methodology. in both spe ... | 2008 | 18784195 |
| functional analysis of ljsut4, a vacuolar sucrose transporter from lotus japonicus. | sucrose transporters in the sut family are important for phloem loading and sucrose uptake into sink tissues. the recent localization of type iii suts atsut4 and hvsut2 to the vacuole membrane suggests that suts also function in vacuolar sucrose transport. the transport mechanism of type iii suts has not been analyzed in detail. ljsut4, a type iii sucrose transporter homolog from lotus japonicus, is expressed in nodules and its transport activity has not been previously investigated. in this rep ... | 2008 | 18618272 |
| substitution of the gene for chloroplast rps16 was assisted by generation of a dual targeting signal. | organelle (mitochondria and chloroplasts in plants) genomes lost a large number of genes after endosymbiosis occurred. even after this major gene loss, organelle genomes still lose their own genes, even those that are essential, via gene transfer to the nucleus and gene substitution of either different organelle origin or de novo genes. gene transfer and substitution events are important processes in the evolution of the eukaryotic cell. gene loss is an ongoing process in the mitochondria and ch ... | 2008 | 18453549 |
| characterization and comparison of intron structure and alternative splicing between medicago truncatula, populus trichocarpa, arabidopsis and rice. | alignment of transcripts and genome sequences yielded a set of alternatively spliced transcripts in four angiosperm genomes: three dicotyledon species medicago truncatula (medicago), populus trichocarpa (poplar) and arabidopsis thaliana (arabidopsis), and the monocotyledon oryzae sativa (rice). intron retention was the predominant mode of alternative splicing (as) in each species, consistent with previous reports for arabidopsis and rice. we analyzed the structure of 5'-splice junctions and obse ... | 2008 | 18438730 |
| low-coverage massively parallel pyrosequencing of cdnas enables proteomics in non-model species: comparison of a species-specific database generated by pyrosequencing with databases from related species for proteome analysis of pea chloroplast envelopes. | proteomics is a valuable tool for establishing and comparing the protein content of defined tissues, cell types, or subcellular structures. its use in non-model species is currently limited because the identification of peptides critically depends on sequence databases. in this study, we explored the potential of a preliminary cdna database for the non-model species pisum sativum created by a small number of massively parallel pyrosequencing (mpss) runs for its use in proteomics and compared it ... | 2008 | 18394738 |
| heterologous expression of iap1, a seed protein from bean modified by indole-3-acetic acid, in arabidopsis thaliana and medicago truncatula. | the seed protein iap1 from bean (pviap1; phaseolus vulgaris l.) that is modified by the phytohormone indole-3-acetic acid (iaa) was heterologously expressed in the two reference plant species arabidopsis thaliana and medicago truncatula. for the transformation of medicago we devised a novel protocol using seedling infiltration. when pviap1 was overexpressed under the control of the constitutive 35scamv promoter in arabidopsis, the plants showed signs of earlier bolting and enhanced branching. ex ... | 2008 | 18097685 |
| construction of a rice glycosyltransferase phylogenomic database and identification of rice-diverged glycosyltransferases. | glycosyltransferases (gts; ec 2.4.x.y) constitute a large group of enzymes that form glycosidic bonds through transfer of sugars from activated donor molecules to acceptor molecules. gts are critical to the biosynthesis of plant cell walls, among other diverse functions. based on the carbohydrate-active enzymes (cazy) database and sequence similarity searches, we have identified 609 potential gt genes (loci) corresponding to 769 transcripts (gene models) in rice (oryza sativa), the reference mon ... | 2008 | 19825588 |
| root exudates regulate soil fungal community composition and diversity. | plants are in constant contact with a community of soil biota that contains fungi ranging from pathogenic to symbiotic. a few studies have demonstrated a critical role of chemical communication in establishing highly specialized relationships, but the general role for root exudates in structuring the soil fungal community is poorly described. this study demonstrates that two model plant species (arabidopsis thaliana and medicago truncatula) are able to maintain resident soil fungal populations b ... | 2008 | 18083870 |
| fractionation of synteny in a genomic region containing tandemly duplicated genes across glycine max, medicago truncatula, and arabidopsis thaliana. | extended comparison of gene sequences found on homeologous soybean bacterial artificial chromosomes to medicago truncatula and arabidopsis thaliana genomic sequences demonstrated a network of synteny within conserved regions interrupted by gene addition and/or deletions. consolidation of gene order among all 3 species provides a picture of ancestral gene order. the observation supports a genome history of fractionation resulting from gene loss/addition and rearrangement. in all 3 species, cluste ... | 2008 | 18316321 |
| planttribes: a gene and gene family resource for comparative genomics in plants. | the planttribes database (http://fgp.huck.psu.edu/tribe.html) is a plant gene family database based on the inferred proteomes of five sequenced plant species: arabidopsis thaliana, carica papaya, medicago truncatula, oryza sativa and populus trichocarpa. we used the graph-based clustering algorithm mcl [van dongen (technical report ins-r0010 2000) and enright et al. (nucleic acids res. 2002; 30: 1575-1584)] to classify all of these species' protein-coding genes into putative gene families, calle ... | 2008 | 18073194 |
| exploring the nuclear proteome of medicago truncatula at the switch towards seed filling. | despite its importance in determining seed composition, and hence quality, regulation of the development of legume seeds is incompletely understood. because of the cardinal role played by the nucleus in gene expression and regulation, we have characterized the nuclear proteome of medicago truncatula at the 12 days after pollination (dap) stage that marks the switch towards seed filling. nano-liquid chromatography-tandem mass spectrometry analysis of nuclear protein bands excised from one-dimensi ... | 2008 | 18643982 |
| advances in development of transgenic pulse crops. | it is three decades since the first transgenic pulse crop has been developed. todate, genetic transformation has been reported in all the major pulse crops like vigna species, cicer arietinum, cajanus cajan, phaseolus spp, lupinus spp, vicia spp and pisum sativum, but transgenic pulse crops have not yet been commercially released. despite the crucial role played by pulse crops in tropical agriculture, transgenic pulse crops have not moved out from laboratories to large farm lands compared to the ... | 2008 | 18055156 |
| conserved microsynteny of npr1 with genes encoding a signal calmodulin-binding protein and a ck1-class protein kinase in beta vulgaris and two other eudicots. | npr1 is a gene of central importance in enabling plants to resist microbial attack. therefore, knowledge of nearby genes is important for genome analysis and possibly for improving disease resistance. in this study, systematic dna sequence analysis, gene annotation, and protein blasts were performed to determine genes near the npr1 gene in beta vulgaris l., medicago truncatula gaertn, and populus trichocarpa torr. & gray, and to access predicted function. microsynteny was discovered for npr1 wit ... | 2008 | 18989375 |
| identification and characterization of nucleotide-binding site-leucine-rich repeat genes in the model plant medicago truncatula. | the nucleotide-binding site (nbs)-leucine-rich repeat (lrr) gene family accounts for the largest number of known disease resistance genes, and is one of the largest gene families in plant genomes. we have identified 333 nonredundant nbs-lrrs in the current medicago truncatula draft genome (mt1.0), likely representing 400 to 500 nbs-lrrs in the full genome, or roughly 3 times the number present in arabidopsis (arabidopsis thaliana). although many characteristics of the gene family are similar to ... | 2008 | 17981990 |
| metabolic and genetic perturbations accompany the modification of galactomannan in seeds of medicago truncatula expressing mannan synthase from guar (cyamopsis tetragonoloba l.). | galactomannan gums are widely used in the food and oil industries, and there is considerable interest in applying biotechnological approaches to improve their physical properties. a mannan synthase from guar (cyamopsis tetragonoloba) was expressed under the control of a bean beta-phaseolin promoter in transgenic medicago truncatula. although the expression of exogenous mannan synthase caused a slight decrease in galactomannan levels in medicago, the molecular weight and viscosity of the polymer ... | 2008 | 18433421 |
| analysis of genome organization, composition and microsynteny using 500 kb bac sequences in chickpea. | the small genome size (740 mb), short life cycle (3 months) and high economic importance as a food crop legume make chickpea (cicer arietinum l.) an important system for genomics research. although several genetic linkage maps using various markers and genomic tools have become available, sequencing efforts and their use are limited in chickpea genomic research. in this study, we explored the genome organization of chickpea by sequencing approximately 500 kb from 11 bac clones (three representin ... | 2008 | 18504542 |
| the lipoxygenase gene family: a genomic fossil of shared polyploidy between glycine max and medicago truncatula. | soybean lipoxygenases (lxs) play important roles in plant resistance and in conferring the distinct bean flavor. lxs comprise a multi-gene family that includes gmlx1, gmlx2 and gmlx3, and many of these genes have been characterized. we were interested in investigating the relationship between the soybean lipoxygenase isozymes from an evolutionary perspective, since soybean has undergone two rounds of polyploidy. here we report the tetrad genome structure of soybean lx regions produced by ancient ... | 2008 | 19105811 |
| transcriptional analysis of highly syntenic regions between medicago truncatula and glycine max using tiling microarrays. | legumes are the third largest family of flowering plants and are unique among crop species in their ability to fix atmospheric nitrogen. as a result of recent genome sequencing efforts, legumes are now one of a few plant families with extensive genomic and transcriptomic data available in multiple species. the unprecedented complexity and impending completeness of these data create opportunities for new approaches to discovery. | 2008 | 18348734 |
| transcriptional profiling of medicago truncatula meristematic root cells. | the root apical meristem of crop and model legume medicago truncatula is a significantly different stem cell system to that of the widely studied model plant species arabidopsis thaliana. in this study we used the affymetrix medicago genechip(r) to compare the transcriptomes of meristem and non-meristematic root to identify root meristem specific candidate genes. | 2008 | 18302802 |
| genome-wide transcriptional analysis of super-embryogenic medicago truncatula explant cultures. | the medicago truncatula (m. truncatula) line 2ha has a 500-fold greater capacity to regenerate plants in culture by somatic embryogenesis than its wild type progenitor jemalong. to understand the molecular basis for the regeneration capacity of this super-embryogenic line 2ha, using affymetrix genechip(r), we have compared transcriptomes of explant leaf cultures of these two lines that were grown on media containing the auxin naa (1-naphthaleneacetic acid) and the cytokinin bap (6-benzylaminopur ... | 2008 | 18950541 |
| responses of the model legume medicago truncatula to the rhizobial exopolysaccharide succinoglycan. | many species of rhizobial bacteria can invade their plant hosts and induce development of symbiotic nitrogen-fixing nodules only if they are able to produce an acidic exopolysaccharide (eps) with certain structural and molecular weight characteristics.1-3sinorhizobium meliloti that produces the functional form of the exopolysaccharide succinoglycan induces formation of invasion structures called infection threads in the root hair cells of its plant hosts alfalfa and medicago truncatula. however, ... | 2008 | 19704531 |
| identification of transcription factors involved in root apex responses to salt stress in medicago truncatula. | the root apex contains meristematic cells that determine root growth and architecture in the soil. specific transcription factor (tf) genes in this region may integrate endogenous signals and external cues to achieve this. early changes in transcriptional responses involving tf genes after a salt stress in medicago truncatula (mt) roots were analysed using two complementary transcriptomic approaches. forty-six salt-regulated tf genes were identified using massive quantitative real-time rt-pcr tf ... | 2008 | 18987888 |
| a community resource for high-throughput quantitative rt-pcr analysis of transcription factor gene expression in medicago truncatula. | medicago truncatula is a model legume species that is currently the focus of an international genome sequencing effort. although several different oligonucleotide and cdna arrays have been produced for genome-wide transcript analysis of this species, intrinsic limitations in the sensitivity of hybridization-based technologies mean that transcripts of genes expressed at low-levels cannot be measured accurately with these tools. amongst such genes are many encoding transcription factors (tfs), whi ... | 2008 | 18611268 |
| trans-regulation of the expression of the transcription factor mthap2-1 by a uorf controls root nodule development. | mthap2-1 is a ccaat-binding transcription factor from the model legume medicago truncatula. we previously showed that mthap2-1 expression is regulated both spatially and temporally by microrna169. here we present a novel regulatory mechanism controlling mthap2-1 expression. alternative splicing of an intron in the mthap2-1 5'leader sequence (ls) becomes predominant during the development of root nodules, leading to the production of a small peptide, uorf1p. our results indicate that binding of u ... | 2008 | 18519645 |
| are there benefits of simultaneous root colonization by different arbuscular mycorrhizal fungi? | arbuscular mycorrhizal fungal (amf) communities were established in pots using fungal isolates from a single field in switzerland. it was tested whether multispecies mixtures provided more phosphorus and supported greater plant growth than single amf species. two host plants, medic (medicago truncatula) and leek (allium porrum), were inoculated with three amf species (glomus mosseae, g. claroideum and g. intraradices), either separately or in mixtures. the composition of the amf communities in t ... | 2008 | 18042204 |
| characterization of pea aphid resistance in medicago truncatula. | to achieve a thorough understanding of plant-aphid interactions, it is necessary to investigate in detail both the plant and insect side of the interaction. the pea aphid (pa; acyrthosiphon pisum) has been selected by an international consortium as the model species for genetics and genomics studies, and the model legume medicago truncatula is a host of this aphid. in this study, we identified resistance to pa in a m. truncatula line, 'jester', with well-characterized resistance to a closely rel ... | 2008 | 18184733 |
| comparative phylogenetic analysis of small gtp-binding genes of model legume plants and assessment of their roles in root nodules. | small gtp-binding genes play an essential regulatory role in a multitude of cellular processes such as vesicle-mediated intracellular trafficking, signal transduction, cytoskeletal organization, and cell division in plants and animals. medicago truncatula and lotus japonicus are important model plants for studying legume-specific biological processes such as nodulation. the publicly available online resources for these plants from websites such as http://www.ncbi.nih.gov, http://www.medicago.org ... | 2008 | 18849296 |
| abscisic acid coordinates nod factor and cytokinin signaling during the regulation of nodulation in medicago truncatula. | nodulation is tightly regulated in legumes to ensure appropriate levels of nitrogen fixation without excessive depletion of carbon reserves. this balance is maintained by intimately linking nodulation and its regulation with plant hormones. it has previously been shown that ethylene and jasmonic acid (ja) are able to regulate nodulation and nod factor signal transduction. here, we characterize the nature of abscisic acid (aba) regulation of nodulation. we show that application of aba inhibits no ... | 2008 | 18931020 |
| mechanism of infection thread elongation in root hairs of medicago truncatula and dynamic interplay with associated rhizobial colonization. | in temperate legumes, endosymbiotic nitrogen-fixing rhizobia gain access to inner root tissues via a specialized transcellular apoplastic compartment known as the infection thread (it). to study it development in living root hairs, a protocol has been established for medicago truncatula that allows confocal microscopic observations of the intracellular dynamics associated with it growth. fluorescent labeling of both the it envelope (atpip2;1-green fluorescent protein) and the host endoplasmic re ... | 2008 | 18931145 |
| the pea sym37 receptor kinase gene controls infection-thread initiation and nodule development. | phenotypic characterization of pea symbiotic mutants has provided a detailed description of the symbiosis with rhizobium leguminosarum bv. viciae strains. we show here that two allelic non-nodulating pea mutants, risnod4 and k24, are affected in the pssym37 gene, encoding a lysm receptor kinase similar to lotus japonicus nfr1 and medicago truncatula lyk3. phenotypic analysis of risnod4 and k24 suggests a role for the sym37 in regulation of infection-thread initiation and nodule development from ... | 2008 | 18986256 |
| efd is an erf transcription factor involved in the control of nodule number and differentiation in medicago truncatula. | mechanisms regulating legume root nodule development are still poorly understood, and very few regulatory genes have been cloned and characterized. here, we describe efd (for ethylene response factor required for nodule differentiation), a gene that is upregulated during nodulation in medicago truncatula. the efd transcription factor belongs to the ethylene response factor (erf) group v, which contains ern1, 2, and 3, three erfs involved in nod factor signaling. the role of efd in the regulation ... | 2008 | 18978033 |
| the rpg gene of medicago truncatula controls rhizobium-directed polar growth during infection. | rhizobia can infect roots of host legume plants and induce new organs called nodules, in which they fix atmospheric nitrogen. infection generally starts with root hair curling, then proceeds inside newly formed, intracellular tubular structures called infection threads. a successful symbiotic interaction relies on infection threads advancing rapidly at their tips by polar growth through successive cell layers of the root toward developing nodule primordia. to identify a plant component that cont ... | 2008 | 18621693 |
| plant host habitat and root exudates shape soil bacterial community structure. | the rhizosphere is active and dynamic in which newly generated carbon, derived from root exudates, and ancient carbon, in soil organic matter (som), are available for microbial growth. stable isotope probing (sip) was used to determine bacterial communities assimilating each carbon source in the rhizosphere of four plant species. wheat, maize, rape and barrel clover (medicago truncatula) were grown separately in the same soil under (13)co(2) (99% of atom (13)c) and dna extracted from rhizosphere ... | 2008 | 18754043 |
| the role of the plant cytoskeleton in the interaction between legumes and rhizobia. | the study of the symbiotic interaction between rhizobia and legumes represents a major theme in plant biology. this interaction results in the formation of nodules, root organs in which the bacteria reduce atmospheric nitrogen into ammonia, which can subsequently be utilized by the plant. the execution of the different developmental stages observed during nodule ontogenesis involves many cellular processes with significant roles for the plant cytoskeleton. a challenging question in cell biology ... | 2008 | 18778422 |
| genetic dissection of resistance to anthracnose and powdery mildew in medicago truncatula. | medicago truncatula was used to characterize resistance to anthracnose and powdery mildew caused by colletotrichum trifolii and erysiphe pisi, respectively. two isolates of e. pisi (ep-p from pea and ep-a from alfalfa) and two races of c. trifolii (races 1 and 2) were used in this study. the a17 genotype was resistant and displayed a hypersensitive response after inoculation with either pathogen, while lines f83005.5 and dza315.16 were susceptible to anthracnose and powdery mildew, respectively. ... | 2008 | 18052883 |
| metabolomics reveals novel pathways and differential mechanistic and elicitor-specific responses in phenylpropanoid and isoflavonoid biosynthesis in medicago truncatula cell cultures. | high-performance liquid chromatography coupled to ultraviolet photodiode array detection and ion-trap mass spectrometry was used to analyze the intra- and extracellular secondary product metabolome of medicago truncatula cell suspension cultures responding to yeast elicitor (ye) or methyl jasmonate (meja). data analysis revealed three phases of intracellular response to ye: a transient response in mainly (iso)flavonoid metabolites such as formononetin and biochanin-a that peaked at 12 to 18 h fo ... | 2008 | 18055588 |
| the model plant medicago truncatula exhibits biparental plastid inheritance. | the plastid, which originated from the endosymbiosis of a cyanobacterium, contains its own plastid dna (ptdna) that exhibits a unique mode of inheritance. approximately 80% of angiosperms show maternal inheritance, whereas the remainder exhibit biparental inheritance of ptdna. here we studied ptdna inheritance in the model legume, medicago truncatula. cytological analysis of mature pollen with dna-specific fluorescent dyes suggested that m. truncatula is one of the few model plants potentially s ... | 2008 | 18065422 |
| closely related members of the medicago truncatula pht1 phosphate transporter gene family encode phosphate transporters with distinct biochemical activities. | phosphorus is one of the essential mineral nutrients required by all living cells. plants assimilate phosphate (pi) from the soil, and their root systems encounter tremendous variation in pi concentration, both temporally and spatially. genome sequence data indicate that plant genomes contain large numbers of genes predicted to encode pi transporters, the functions of which are largely unexplored. here we present a comparative analysis of four very closely related pi transporters of the pht1 fam ... | 2008 | 18596039 |
| a gene expression atlas of the model legume medicago truncatula. | legumes played central roles in the development of agriculture and civilization, and today account for approximately one-third of the world's primary crop production. unfortunately, most cultivated legumes are poor model systems for genomic research. therefore, medicago truncatula, which has a relatively small diploid genome, has been adopted as a model species for legume genomics. to enhance its value as a model, we have generated a gene expression atlas that provides a global view of gene expr ... | 2008 | 18410479 |