direct purification of detergent-insoluble membranes from medicago truncatula root microsomes: comparison between floatation and sedimentation.membrane microdomains are defined as highly dynamic, sterol- and sphingolipid-enriched domains that resist to solubilization by non-ionic detergents. in plants, these so-called detergent insoluble membrane (dim) fractions have been isolated from plasma membrane by using conventional ultracentrifugation on density gradient (g). in animals, a rapid (r) protocol, based on sedimentation at low speed, which avoids the time-consuming sucrose gradient, has also been developed to recover dims from micro ...201425267185
genome-wide identification and expression profiling analysis of the aux/iaa gene family in medicago truncatula during the early phase of sinorhizobium meliloti infection.auxin/indoleacetic acid (aux/iaa) genes, coding a family of short-lived nuclear proteins, play key roles in wide variety of plant developmental processes, including root system regulation and responses to environmental stimulus. however, how they function in auxin signaling pathway and symbiosis with rhizobial in medicago truncatula are largely unknown. the present study aims at gaining deeper insight on distinctive expression and function features of aux/iaa family genes in medicago truncatula ...201425226164
symbiotic plant peptides eliminate candida albicans both in vitro and in an epithelial infection model and inhibit the proliferation of immortalized human cells.the increasing number of multidrug-resistant microbes now emerging necessitates the identification of novel antimicrobial agents. plants produce a great variety of antimicrobial peptides including hundreds of small, nodule-specific cysteine-rich ncr peptides that, in the legume medicago truncatula, govern the differentiation of endosymbiotic nitrogen fixing bacteria and, in vitro, can display potent antibacterial activities. in this study, the potential candidacidal activity of 19 ncr peptides w ...201425243129
nodule carbohydrate catabolism is enhanced in the medicago truncatula a17-sinorhizobium medicae wsm419 symbiosis.the symbiotic association between medicago truncatula and sinorhizobium meliloti is a well-established model system in the legume-rhizobium community. despite its wide use, the symbiotic efficiency of this model has been recently questioned and an alternative microsymbiont, s. medicae, has been proposed. however, little is known about the physiological mechanisms behind the higher symbiotic efficiency of s. medicae wsm419. in the present study, we inoculated m. truncatula jemalong a17 with eithe ...201425221545
genomic characterization of the leed..peeds, a gene family unique to the medicago lineage.the leed..peed (lp) gene family in medicago truncatula (a17) is composed of 13 genes coding small putatively secreted peptides with one to two conserved domains of negatively charged residues. this family is not present in the genomes of glycine max, lotus japonicus, or the irlc species cicer arietinum. lp genes were also not detected in a trifolium pratense draft genome or pisum sativum nodule transcriptome, which were sequenced de novo in this study, suggesting that the lp gene family arose wi ...201425155275
rna-seq transcriptome profiling reveals that medicago truncatula nodules acclimate n₂ fixation before emerging p deficiency reaches the nodules.legume nodules are plant tissues with an exceptionally high concentration of phosphorus (p), which, when there is scarcity of p, is preferentially maintained there rather than being allocated to other plant organs. the hypothesis of this study was that nodules are affected before the p concentration in the organ declines during whole-plant p depletion. nitrogen (n₂) fixation and p concentration in various organs were monitored during a whole-plant p-depletion process in medicago truncatula. nodu ...201425151618
the 2ha line of medicago truncatula has characteristics of an epigenetic mutant that is weakly ethylene insensitive.the medicago truncatula 2ha seed line is highly embryogenic while the parental line jemalong rarely produces embryos. the 2ha line was developed from one of the rare jemalong regenerates and this method for obtaining a highly regenerable genotype in m. truncatula is readily reproducible suggesting an epigenetic mechanism. microarray transcriptomic analysis showed down regulation of an ethylene insensitive 3-like gene in 2ha callus which provided an approach to investigating epigenetic regulation ...201424952658
plant responses to bacterial n-acyl l-homoserine lactones are dependent on enzymatic degradation to l-homoserine.many bacteria use quorum sensing (qs) to regulate phenotypes that ultimately benefit the bacterial population at high cell densities. these qs-dependent phenotypes are diverse and can have significant impacts on the bacterial host, including virulence factor production, motility, biofilm formation, bioluminescence, and root nodulation. as bacteria and their eukaryotic hosts have coevolved over millions of years, it is not surprising that certain hosts appear to be able to sense qs signals, poten ...201424918118
keel petal incision: a simple and efficient method for genetic crossing in medicago truncatula.genetic crossing is an essential tool in both forward and reverse genetic approaches to understand the biological functions of genes. for medicago truncatula (barrel medic) various crossing techniques have been used which differ in the methods used to dissect the female parent's unopened flower bud to remove immature anthers for prevention of self-pollination. previously described methods including front, side or back incision methods may damage the flower bud, impeding successful fertilization ...201424966878
the activity of nodules of the supernodulating mutant mtsunn is not limited by photosynthesis under optimal growth conditions.legumes match the nodule number to the n demand of the plant. when a mutation in the regulatory mechanism deprives the plant of that ability, an excessive number of nodules are formed. these mutants show low productivity in the fields, mainly due to the high carbon burden caused through the necessity to supply numerous nodules. the objective of this study was to clarify whether through optimal conditions for growth and co2 assimilation a higher nodule activity of a supernodulating mutant of medi ...201424727372
patterns of divergence of a large family of nodule cysteine-rich peptides in accessions of medicago truncatula.the nodule cysteine-rich (ncr) groups of defensin-like (defl) genes are one of the largest gene families expressed in the nodules of some legume plants. they have only been observed in the inverted repeat loss clade (irlc) of legumes, which includes the model legume medicago truncatula. ncrs are reported to play an important role in plant-microbe interactions. to understand their diversity we analyzed their expression and sequence polymorphisms among four accessions of m. truncatula. a significa ...201424635121
genome sequence of the medicago-nodulating ensifer meliloti commercial inoculant strain rri128.ensifer meliloti strain rri128 is an aerobic, motile, gram-negative, non-spore-forming rod. rri128 was isolated from a nodule recovered from the roots of barrel medic (medicago truncatula) grown in the greenhouse and inoculated with soil collected from victoria, australia. the strain is used in commercial inoculants in australia. rri128 nodulates and forms an effective symbiosis with a diverse range of lucerne cultivars (medicago sativa) and several species of annual medic (m. truncatula, medica ...201425197447
short-term molecular acclimation processes of legume nodules to increased external oxygen concentration.nitrogenase is an oxygen labile enzyme. microaerobic conditions within the infected zone of nodules are maintained primarily by an oxygen diffusion barrier (odb) located in the nodule cortex. flexibility of the odb is important for the acclimation processes of nodules in response to changes in external oxygen concentration. the hypothesis of the present study was that there are additional molecular mechanisms involved. nodule activity of medicago truncatula plants were continuously monitored dur ...201526779207
up-regulation of abscisic acid signaling pathway facilitates aphid xylem absorption and osmoregulation under drought stress.the activation of the abscisic acid (aba) signaling pathway reduces water loss from plants challenged by drought stress. the effect of drought-induced aba signaling on the defense and nutrition allocation of plants is largely unknown. we postulated that these changes can affect herbivorous insects. we studied the effects of drought on different feeding stages of pea aphids in the wild-type a17 of medicago truncatula and aba signaling pathway mutant sta-1. we examined the impact of drought on pla ...201526546578
the strigolactone biosynthesis gene dwarf27 is co-opted in rhizobium symbiosis.strigolactones are a class of plant hormones whose biosynthesis is activated in response to phosphate starvation. this involves several enzymes, including the carotenoid cleavage dioxygenases 7 (ccd7) and ccd8 and the carotenoid isomerase dwarf27 (d27). d27 expression is known to be responsive to phosphate starvation. in medicago truncatula and rice (oryza sativa) this transcriptional response requires the gras-type proteins nsp1 and nsp2; both proteins are essential for rhizobium induced root n ...201526503135
rhizobial peptidase hrrp cleaves host-encoded signaling peptides and mediates symbiotic compatibility.legume-rhizobium pairs are often observed that produce symbiotic root nodules but fail to fix nitrogen. using the sinorhizobium meliloti and medicago truncatula symbiotic system, we previously described several naturally occurring accessory plasmids capable of disrupting the late stages of nodule development while enhancing bacterial proliferation within the nodule. we report here that host range restriction peptidase (hrrp), a gene found on one of these plasmids, is capable of conferring both t ...201526401024
multiple autoregulation of nodulation (aon) signals identified through split root analysis of medicago truncatula sunn and rdn1 mutants.nodulation is energetically costly to the host: legumes balance the nitrogen demand with the energy expense by limiting the number of nodules through long-distance signaling. a split root system was used to investigate systemic autoregulation of nodulation (aon) in medicago truncatula and the role of the aon genes rdn1 and sunn in the regulatory circuit. developing nodule primordia did not trigger aon in plants carrying mutations in rdn1 and sunn genes, while wild type plants had fully induced a ...201527135324
genome-wide identification and expression analysis of auxin response factor gene family in medicago truncatula.auxin response factors (arfs) bind specifically to auxin response elements (auxres) in the promoters of down-stream target genes and play roles in plant responses to diverse environmental factors. using the latest updated medicago truncatula reference genome sequence, a comprehensive characterization and analysis of 24 mtarf (m. truncatula arf) genes were performed. to uncover the basic information and functions of mtarf genes during symbiosis, we analyzed the expression patterns of mtarf genes ...201525759704
duration and intensity of shade differentially affects mycorrhizal growth- and phosphorus uptake responses of medicago truncatula.plant and fungal partners in arbuscular mycorrhizal symbiosis trade mineral nutrients for carbon, with the outcome of this relationship for plant growth and nutrition being highly context-dependent and changing with the availability of resources as well as with the specific requirements of the different partners. here we studied how the model legume medicago truncatula, inoculated or not with a mycorrhizal fungus rhizophagus irregularis, responded to a gradient of light intensities applied over ...201525763002
integrated metabolomics and transcriptomics reveal enhanced specialized metabolism in medicago truncatula root border cells.integrated metabolomics and transcriptomics of medicago truncatula seedling border cells and root tips revealed substantial metabolic differences between these distinct and spatially segregated root regions. large differential increases in oxylipin-pathway lipoxygenases and auxin-responsive transcript levels in border cells corresponded to differences in phytohormone and volatile levels compared with adjacent root tips. morphological examinations of border cells revealed the presence of signific ...201525667316
identification and network-enabled characterization of auxin response factor genes in medicago truncatula.the auxin response factor (arf) family of transcription factors is an important regulator of environmental response and symbiotic nodulation in the legume medicago truncatula. while previous studies have identified members of this family, a recent spurt in gene expression data coupled with genome update and reannotation calls for a reassessment of the prevalence of arf genes and their interaction networks in m. truncatula. we performed a comprehensive analysis of the m. truncatula genome and tra ...201628018393
expression analysis of pin genes in root tips and nodules of medicago truncatula.polar auxin transport is dependent on the family of pin-formed proteins (pins), which are membrane transporters of anionic indole-3-acetic acid (iaa(-)). it is assumed that polar auxin transport may be essential in the development and meristematic activity maintenance of medicago truncatula (m. truncatula) root nodules. however, little is known about the involvement of specific pin proteins in m. truncatula nodulation. using real-time quantitative pcr, we analyzed the expression patterns of all ...201627463709
a single amino acid substitution in a chitinase of the legume medicago truncatula is sufficient to gain nod-factor hydrolase activity.the symbiotic interaction between nitrogen-fixing rhizobia and legumes depends on lipo-chitooligosaccharidic nod-factors (nfs). the nf hydrolase mtnfh1 of medicago truncatula is a symbiotic enzyme that hydrolytically inactivates nfs with a c16 : 2 acyl chain produced by the microsymbiont sinorhizobium meliloti 1021. mtnfh1 is related to class v chitinases (glycoside hydrolase family 18) but lacks chitinase activity. here, we investigated the substrate specificity of mtnfh1-related proteins. mtch ...201627383628
molecular signals controlling the inhibition of nodulation by nitrate in medicago truncatula.the presence of nitrogen inhibits legume nodule formation, but the mechanism of this inhibition is poorly understood. we found that 2.5 mm nitrate and above significantly inhibited nodule initiation but not root hair curling in medicago trunatula. we analyzed protein abundance in m. truncatula roots after treatment with either 0 or 2.5 mm nitrate in the presence or absence of its symbiont sinorhizobium meliloti after 1, 2 and 5 days following inoculation. two-dimensional gel electrophoresis comb ...201627384556
mass spectrometric-based selected reaction monitoring of protein phosphorylation during symbiotic signaling in the model legume, medicago truncatula.unlike the major cereal crops corn, rice, and wheat, leguminous plants such as soybean and alfalfa can meet their nitrogen requirement via endosymbiotic associations with soil bacteria. the establishment of this symbiosis is a complex process playing out over several weeks and is facilitated by the exchange of chemical signals between these partners from different kingdoms. several plant components that are involved in this signaling pathway have been identified, but there is still a great deal ...201627203723
organic nitrogen-driven stimulation of arbuscular mycorrhizal fungal hyphae correlates with abundance of ammonia oxidizers.large fraction of mineral nutrients in natural soil environments is recycled from complex and heterogeneously distributed organic sources. these sources are explored by both roots and associated mycorrhizal fungi. however, the mechanisms behind the responses of arbuscular mycorrhizal (am) hyphal networks to soil organic patches of different qualities remain little understood. therefore, we conducted a multiple-choice experiment examining hyphal responses to different soil patches within the root ...201627242732
wrky domain-encoding genes of a crop legume chickpea (cicer arietinum): comparative analysis with medicago truncatula wrky family and characterization of group-iii gene(s).the wrky genes have been identified as important transcriptional modulators predominantly during the environmental stresses, but they also play critical role at various stages of plant life cycle. we report the identification of wrky domain (wd)-encoding genes from galegoid clade legumes chickpea (cicer arietinum l.) and barrel medic (medicago truncatula). in total, 78 and 98 wd-encoding genes were found in chickpea and barrel medic, respectively. comparative analysis suggests the presence of bo ...201627060167
rapid identification of causative insertions underlying medicago truncatula tnt1 mutants defective in symbiotic nitrogen fixation from a forward genetic screen by whole genome the model legume medicago truncatula, the near saturation genome-wide tnt1 insertion mutant population in ecotype r108 is a valuable tool in functional genomics studies. forward genetic screens have identified many tnt1 mutants defective in nodule development and symbiotic nitrogen fixation (snf). however, progress toward identifying the causative mutations of these symbiotic mutants has been slow because of the high copy number of tnt1 insertions in some mutant plants and inefficient recover ...201626920390
exploring the genetic diversity of ethiopian grass pea (lathyrus sativus l.) using est-ssr markers.expressed sequence tags (ests) in public databases and cross-species transferable markers are considered to be a cost-effective means for developing sequence-based markers for less-studied species. in this study, est-simple sequence repeat (ssr) markers developed from lathyrus sativus l. est sequences and cross-transferable est-ssrs derived from medicago truncatula l. were utilized to investigate the genetic diversity among grass pea populations from ethiopia. a total of 45 alleles were detected ...201122924019
simple and efficient methods to generate split roots and grafted plants useful for long-distance signaling studies in medicago truncatula and other small plants. 201222971438
advances in faba bean genetics and genomics.vicia faba l, is a globally important grain legume whose main centers of diversity are the fertile crescent and mediterranean basin. because of its small number (six) of exceptionally large and easily observed chromosomes it became a model species for plant cytogenetics the 70s and 80s. it is somewhat ironic therefore, that the emergence of more genomically tractable model plant species such as arabidopsis and medicago coincided with a marked decline in genome research on the formerly favored pl ...201627597858
rj (rj) genes involved in nitrogen-fixing root nodule formation in has long been known that formation of symbiotic root nodules in soybean (glycine max (l.) merr.) is controlled by several host genes referred to as rj (rj) genes, but molecular cloning of these genes has been hampered by soybean's complicated genome structure and large genome size. progress in molecular identification of legume genes involved in root nodule symbiosis have been mostly achieved by using two model legumes, lotus japonicus and medicago truncatula, that have relatively simple and ...201223136493
detailed analysis of putative genes encoding small proteins in legume genomes.diverse plant genome sequencing projects coupled with powerful bioinformatics tools have facilitated massive data analysis to construct specialized databases classified according to cellular function. however, there are still a considerable number of genes encoding proteins whose function has not yet been characterized. included in this category are small proteins (sps, 30-150 amino acids) encoded by short open reading frames (sorfs). sps play important roles in plant physiology, growth, and dev ...201323802007
repetitive dna in the pea (pisum sativum l.) genome: comprehensive characterization using 454 sequencing and comparison to soybean and medicago truncatula.extraordinary size variation of higher plant nuclear genomes is in large part caused by differences in accumulation of repetitive dna. this makes repetitive dna of great interest for studying the molecular mechanisms shaping architecture and function of complex plant genomes. however, due to methodological constraints of conventional cloning and sequencing, a global description of repeat composition is available for only a very limited number of higher plants. in order to provide further data re ...200718031571
aphanomyces euteiches cell wall fractions containing novel glucan-chitosaccharides induce defense genes and nuclear calcium oscillations in the plant host medicago truncatula.n-acetylglucosamine-based saccharides (chitosaccharides) are components of microbial cell walls and act as molecular signals during host-microbe interactions. in the legume plant medicago truncatula, the perception of lipochitooligosaccharide signals produced by symbiotic rhizobia and arbuscular mycorrhizal fungi involves the nod factor perception (nfp) lysin motif receptor-like protein and leads to the activation of the so-called common symbiotic pathway. in rice and arabidopsis, lysin motif re ...201324086432
identification and expression analysis of burp domain-containing genes in medicago truncatula.burp domain-containing proteins belong to a newly identified protein class that is unique to plants and plays an important role in plant development and metabolism. although systematic characterization of burp domain-containing proteins have been carried out in many species, such as rice, poplar and maize, little is known about burp domain-containing proteins in medicago. in this study, multiple bioinformatics approaches were employed to identify all the members of burp family genes in medicago. ...201627148311
snp discovery and genetic mapping using genotyping by sequencing of whole genome genomic dna from a pea ril population.progress in genetics and breeding in pea still suffers from the limited availability of molecular resources. snp markers that can be identified through affordable sequencing processes, without the need for prior genome reduction or a reference genome to assemble sequencing data would allow the discovery and genetic mapping of thousands of molecular markers. such an approach could significantly speed up genetic studies and marker assisted breeding for non-model species.201626892170
mutant: a family of mutator-like transposable elements targeting ta microsatellites in medicago truncatula.transposable elements (tes) are mobile dna segments, abundant and dynamic in plant genomes. because their mobility can be potentially deleterious to the host, a variety of mechanisms evolved limiting that negative impact, one of them being preference for a specific target insertion site. here, we describe a family of mutator-like dna transposons in medicago truncatula targeting ta microsatellites. we identified 218 copies of mutants and an element carrying a complete orf encoding a mudra-like tr ...201525981486
high toxicity and specificity of the saponin 3-glca-28-ararhaxyl-medicagenate, from medicago truncatula seeds, for sitophilus oryzae.because of the increasingly concern of consumers and public policy about problems for environment and for public health due to chemical pesticides, the search for molecules more safe is currently of great importance. particularly, plants are able to fight the pathogens as insects, bacteria or fungi; so that plants could represent a valuable source of new molecules.201222536832
two classes of the cdh1-type activators of the anaphase-promoting complex in plants: novel functional domains and distinct regulation.the cdc20 and cdh1/fzr proteins are the substrate-specific activators of the anaphase-promoting complex (apc). in medicago truncatula, the mtccs52a and mtccs52b proteins represent two subgroups of the cdh1-type activators, which display differences in their cell cycle regulation, structure, and function. the ccs52a transcripts are present in all phases of the cell cycle. by contrast, expression of ccs52b is restricted to late g2-phase and m-phase, and its induced overexpression in by2 cells inhi ...200414742878
isolation of protein complexes from the model legume medicago truncatula by tandem affinity purification in hairy root cultures.tandem affinity purification coupled to mass spectrometry (tap-ms) is one of the most powerful techniques to isolate protein complexes and elucidate protein interaction networks. here, we describe the development of a tap-ms strategy for the model legume medicago truncatula, which is widely studied for its ability to produce valuable natural products and to engage in endosymbiotic interactions. as biological material, transgenic hairy roots, generated through agrobacterium rhizogenes-mediated tr ...201627377668
the medicago truncatula mtrbohe gene is activated in arbusculated cells and is involved in root cortex colonization.our study demonstrated that the napdh oxidase gene mtrbohe is expressed in arbusculated cells and plays a role in arbuscule development. plant nadph oxidases, known as respiratory burst oxidase homologs (rboh), belong to a multigenic family that plays an important role in the regulation of plant development and responses to biotic and abiotic stresses. in this study, we monitored the expression profiles of five rboh genes (mtrboha, mtrbohb, mtrbohe, mtrbohg, mtrbohf) in the roots of the model sp ...201626403286
gene silencing in medicago truncatula roots using rnai.medicago truncatula is used widely as a model system for studies of root symbioses, interactions with parasitic nematodes and fungal pathogens, as well as studies of development and secondary metabolism. in medicago truncatula as well as other legumes, rna interference (rnai) coupled with agrobacterium rhizogenes-mediated root transformation, has been used very successfully for analyses of gene function in roots. one of the major advantages of this approach is the ease and relative speed with wh ...201323996315
trans-specific gene silencing of acetyl-coa carboxylase in a root-parasitic plant.parasitic species of the family orobanchaceae are devastating agricultural pests in many parts of the world. the control of weedy orobanchaceae spp. is challenging, particularly due to the highly coordinated life cycles of the parasite and host plants. although host genetic resistance often provides the foundation of plant pathogen management, few genes that confer resistance to root parasites have been identified and incorporated into crop species. members of the family orobanchaceae acquire wa ...201323383721
aeschynomene evenia, a model plant for studying the molecular genetics of the nod-independent rhizobium-legume symbiosis.research on the nitrogen-fixing symbiosis has been focused, thus far, on two model legumes, medicago truncatula and lotus japonicus, which use a sophisticated infection process involving infection thread formation. however, in 25% of the legumes, the bacterial entry occurs more simply in an intercellular fashion. among them, some aeschynomene spp. are nodulated by photosynthetic bradyrhizobium spp. that do not produce nod factors. this interaction is believed to represent a living testimony of t ...201222475377
type iv effector proteins involved in the medicago-sinorhizobium this study, we investigated genetic elements of the type iv secretion system (t4ss) found in sinorhizobium spp. and the role they play in symbiosis. sinorhizobium meliloti and s. medicae each contain a putative t4ss similar to that used by agrobacterium tumefaciens during pathogenesis. the cre reporter assay for translocation system was used to validate potential effector proteins. both s. meliloti and s. medicae contained the effector protein tfea, which was translocated into the host plant. ...201727918247
infiltration-rnaseq: transcriptome profiling of agrobacterium-mediated infiltration of transcription factors to discover gene function and expression networks in plants.transcription factors (tfs) coordinate precise gene expression patterns that give rise to distinct phenotypic outputs. the identification of genes and transcriptional networks regulated by a tf often requires stable transformation and expression changes in plant cells. however, the production of stable transformants can be slow and laborious with no guarantee of success. furthermore, transgenic plants overexpressing a tf of interest can present pleiotropic phenotypes and/or result in a high numb ...201627777610
a high-throughput rna interference (rnai)-based approach using hairy roots for the study of plant-rhizobia interactions.legumes are major contributors to sustainable agriculture; their key feature is their ability to fix atmospheric nitrogen through symbiotic nitrogen fixation. legumes are often recalcitrant to regeneration and transformation by agrobacterium tumefaciens; however, a. rhizogenes-mediated root transformation and composite plant generation are rapid and convenient alternatives to study root biology, including root nodule symbiosis. rna interference (rnai), coupled with a. rhizogenes-mediated root tr ...201525740364
transient gene expression in medicago truncatula leaves via agroinfiltration.transient expression is a powerful method for the functional characterization of genes. in this chapter, we outline a protocol for the transient expression of constructs in medicago truncatula leaves using agrobacterium tumefaciens infiltration. using quantitative real-time pcr we demonstrate that the infiltration of a construct containing the legume anthocyanin production 1 (lap1) transcription factor results in the strong upregulation of key biosynthetic genes and the accumulation of anthocyan ...201323996318
stable transformation of medicago truncatula cv. jemalong for gene analysis using agrobacterium tumefaciens.medicago truncatula is a model legume that has all the genomic resources to be suitable as a model for functional genomics. transformation to produce transgenic plants is part of this toolkit, enabling a spectrum of approaches to study gene function: including knockdown, overexpression, reporter genes for gene expression, and proteins tagged with fluorescent proteins such as gfp. a special genetic line is necessary for transformation and jemalong 2ha derived from cv. jemalong is used in the meth ...201323996317
transformation of barrel medic (medicago truncatula gaertn.) by agrobacterium tumefaciens and regeneration via somatic embryogenesis of transgenic plants with the mtenod12 nodulin promoter fused to the gus reporter gene.fertile and stable transgenic plants of the model legume medicago truncatula gaertn. were obtained through transformation of leaf tissue with the disarmed agrobacterium tumefaciens strain lba4404 and in vitro regeneration via somatic embryogenesis. an optimised transformation/regeneration protocol has been established for two genotypes of the cultivar jemalong, including a previously described highly embryogenic line (nolan et al. 1989, plant cell rep. 8: 278-281). using this protocol, transgeni ...199624178347
[the plant growth-promoting rhizobacterium arthrobacter agilis umcv2 endophytically colonizes medicago truncatula].arthrobacter agilis umcv2 is a rhizosphere bacterium that promotes legume growth by solubilization of iron, which is supplied to the plant. a second growth promotion mechanism produces volatile compounds that stimulate iron uptake activities. additionally, a. agilis umcv2 is capable of inhibiting the growth of phytopathogens. a combination of quantitative polymerase chain reaction and fluorescence in situ hybridization techniques were used here to detect and quantify the presence of the bacteriu ...201627916328
identification of lipoxygenase (lox) genes from legumes and their responses in wild type and cultivated peanut upon aspergillus flavus infection.lipoxygenase (lox) genes are widely distributed in plants and play crucial roles in resistance to biotic and abiotic stress. although they have been characterized in various plants, little is known about the evolution of legume lox genes. in this study, we identified 122 full-length lox genes in arachis duranensis, arachis ipaënsis, cajanus cajan, cicer arietinum, glycine max, lotus japonicus and medicago truncatula. in total, 64 orthologous and 36 paralogous genes were identified. the full-leng ...201627731413
isolation and characterization of putative endophytic bacteria antagonistic to phoma tracheiphila and verticillium albo-atrum.a collection of 200 bacterial isolates recovered from citrus plants (citrus limon, citrus sinensis, and citrus reticulata), medicago truncatula and laurus nobilis, was established. in vitro screening indicated that 28 isolates exhibited an inhibitory activity against the vascular pathogens phoma tracheiphila and verticillium albo-atrum. isolates were screened according to their hydrolytic activities, plant growth-promoting bacteria (pgpb) abilities, as well as for the presence of nonribosomal pe ...201425074353
isolation of a chitinolytic bacillus licheniformis s213 strain exerting a biological control against phoma medicaginis infection.among nine chitinase-producing strains isolated from tunisian soil, one isolate called s213 exhibited a potent chitinolytic activity. s213 strain was identified as bacillus licheniformis by api 50ch system and sequence analysis of its partial 16s ribosomal dna. chitinolytic activity was induced either by colloidal chitin or fungal cell walls, and the highest chitinase activity reached at the late stationary phase exhibiting optimal temperature and ph of 50-60 °c and ph 6.0, respectively. sds-pag ...201525666369
isolation and characterization of genetic variability in bacteria with β-hemolytic and antifungal activity isolated from the rhizosphere of medicago truncatula the present study, we analyzed the frequency of hemolytic and antifungal activities in bacterial isolates from the rhizosphere of medicago truncatula plants. of the 2000 bacterial colonies, 96 showed β-hemolytic activities (frequency, 4.8 x 10(-2)). hemolytic isolates were analyzed for their genetic diversity by using random amplification of polymorphic dna, yielding 88 haplotypes. the similarity coefficient of nei and li showed a polymorphic diversity ranging from 0.3 to 1. additionally, 8 o ...201425062484
putative use of a bacillus subtilis l194 strain for biocontrol of phoma medicaginis in medicago truncatula antagonist l194 strain against phoma medicaginis pathogenic fungi was isolated from tunisian soil (vicinity of tunis) and identified as bacillus subtilis based on biochemical characteristics and partial 16s rdna sequence. when cells were grown in a minimal medium for 24 h, spore culture supernatant exhibited 2-fold higher antifungal activity than vegetative cells. maldi-tof mass spectrometry analysis showed that l194 spores produced mainly iturins, surfactins and fengycins with long-chain fat ...201222579659
crn13 candidate effectors from plant and animal eukaryotic pathogens are dna-binding proteins which trigger host dna damage successfully colonize their host, pathogens produce effectors that can interfere with host cellular processes. here we investigated the function of crn13 candidate effectors produced by plant pathogenic oomycetes and detected in the genome of the amphibian pathogenic chytrid fungus batrachochytrium dendrobatidis (bdcrn13). when expressed in nicotiana, aecrn13, from the legume root pathogen aphanomyces euteiches, increases the susceptibility of the leaves to the oomycete phytophthora capsici. ...201626700936
salicylic acid treatment and expression of an rna-dependent rna polymerase 1 transgene inhibit lethal symptoms and meristem invasion during tobacco mosaic virus infection in nicotiana rna-dependent rna polymerases (rdrs) 1 and 6 contribute to antiviral rna silencing in plants. rdr6 is constitutively expressed and was previously shown to limit invasion of nicotiana benthamiana meristem tissue by potato virus x and thereby inhibit disease development. rdr1 is inducible by salicylic acid (sa) and several other phytohormones. but although it contributes to basal resistance to tobacco mosaic virus (tmv) it is dispensable for sa-induced resistance in inoculated leaves. the lab ...201626757721
nodulation studies in the model legume medicago truncatula: advantages of using the constitutive ef1alpha promoter and limitations in detecting fluorescent reporter proteins in nodule tissues.the cauliflower mosaic virus 35s promoter currently is being used in rnai-based approaches for attenuating host gene expression during legume root nodule development and also for the expression of fluorescent reporters in nodule tissues. in this study, we have evaluated the expression of this promoter in the indeterminate nodules of the model plant medicago truncatula. our results clearly show that the 35s promoter is inactive in both the nodule meristem and in bacteroid-containing cells of the ...200717849706
genetic transformation of medicago truncatula using agrobacterium with genetically modified ri and disarmed ti plasmids.fertile transgenic plants of the annual pasture legume medicago truncatula were obtained by agrobacterium-mediated transformation, utilising a disarmed ti plasmid and a binary vector containing the kanamycin resistance gene under the control of the cauliflower mosaic virus 35s promoter. factors contributing to the result included an improved plant regeneration protocol and the use of explants from a plant identified as possessing high regeneration capability from tissue culture. genes present on ...199224213541
molecular characterization of a trisegmented mycovirus from the plant pathogenic fungus colletotrichum gloeosporioides.a novel double-stranded rna (dsrna) mycovirus, consisting of three dsrna genome segments and possibly belonging to the family chrysoviridae, was isolated from the filamentous phytopathogenic fungus colletotrichum gloeosporioides and designated as colletotrichum gloeosprioides chrysovirus 1 (cgcv1). the three dsrnas of the cgcv1 genome with lengths of 3397, 2869, and 2630 bp (dsrnas1-3) were found to contain a single open reading frame (orf) putatively encoding the rna-dependent rna polymerase (r ...201627690081
cloning and biochemical characterization of indole-3-acetic acid-amino acid synthetase psgh3 from pea.phytohormone conjugation is one of the mechanisms that maintains a proper hormonal homeostasis and that is necessary for the realization of physiological responses. gretchen hagen 3 (gh3) acyl acid amido synthetases convert indole-3-acetic acid (iaa) to iaa-amino acid conjugates by atp-dependent reactions. iaa-aspartate (iaa-asp) exists as a predominant amide conjugate of auxin in pea tissues and acts as an intermediate during iaa catabolism. here we report a novel recombinant indole-3-acetic ac ...201627235647
how grow-and-switch gravitropism generates root coiling and root waving growth responses in medicago truncatula.experimental studies show that plant root morphologies can vary widely from straight gravity-aligned primary roots to fractal-like root architectures. however, the opaqueness of soil makes it difficult to observe how environmental factors modulate these patterns. here, we combine a transparent hydrogel growth medium with a custom built 3d laser scanner to directly image the morphology of medicago truncatula primary roots. in our experiments, root growth is obstructed by an inclined plane in the ...201526432881
heterologous overexpression of vigna radiata epoxide hydrolase in escherichia coli and its catalytic performance in enantioconvergent hydrolysis of p-nitrostyrene oxide into (r)-p-nitrophenyl glycol.two native epoxide hydrolases (ehs) were previously discovered from mung bean powder (vigna radiata), both of which can catalyze the enantioconvergent hydrolysis of p-nitrostyrene oxide (pnso). in this study, the encoding gene of vreh1 was successfully cloned from the cdna of v. radiata by rt-pcr and rapid amplification of cdna ends (race) technologies. high homologies were found to two putative ehs originated from glycine max (80%) and medicago truncatula (79%). the vreh1 gene constructed in pe ...201423615737
medicago truncatula dihydrodipicolinate synthase (dhdps) enzymes display novel regulatory properties.lysine biosynthesis in plants is tightly regulated by feedback inhibition of the end product on the first enzyme of the lysine-specific branch, dihydrodipicolinate synthase (dhdps). three complete dhdps coding sequences and one partial sequence were obtained in medicago truncatula via inverse pcr. analysis of the mtdhdps sequences indicated the presence of isozymes (mtdhdps2 and mtdhdps3) with multiple amino acid substitutions on positions previously shown to be involved in feedback inhibition a ...201323329373
functional characterization of proanthocyanidin pathway enzymes from tea and their application for metabolic engineering.tea (camellia sinensis) is rich in specialized metabolites, especially polyphenolic proanthocyanidins (pas) and their precursors. to better understand the pa pathway in tea, we generated a complementary dna library from leaf tissue of the blister blight-resistant tea cultivar tri2043 and functionally characterized key enzymes responsible for the biosynthesis of pa precursors. structural genes encoding enzymes involved in the general phenylpropanoid/flavonoid pathway and the pa-specific branch pa ...201323288883
a functional genomics approach to (iso)flavonoid glycosylation in the model legume medicago truncatula.analysis of over 200,000 expressed sequence tags from a range of medicago truncatula cdna libraries resulted in the identification of over 150 different family 1 glycosyltransferase (ugt) genes. of these, 63 were represented by full length clones in an est library collection. among these, 19 gave soluble proteins when expressed in e. coli, and these were screened for catalytic activity against a range of flavonoid and isoflavonoid substrates using a high-throughput hplc assay method. eight ugts ...200717437063
transcriptome analysis of the fungal pathogen fusarium oxysporum f. sp. medicaginis during colonisation of resistant and susceptible medicago truncatula hosts identifies differential pathogenicity profiles and novel candidate effectors.pathogenic members of the fusarium oxysporum species complex are responsible for vascular wilt disease on many important crops including legumes, where they can be one of the most destructive disease causing necrotrophic fungi. we previously developed a model legume-infecting pathosystem based on the reference legume medicago truncatula and a pathogenic f. oxysporum forma specialis (f. sp.) medicaginis (fom). to dissect the molecular pathogenicity arsenal used by this root-infecting pathogen, we ...201627809762
jasmonate signalling and defence responses in the model legume medicago truncatula-a focus on responses to fusarium wilt disease.jasmonate (ja)-mediated defences play important roles in host responses to pathogen attack, in particular to necrotrophic fungal pathogens that kill host cells in order to extract nutrients and live off the dead plant tissue. the root-infecting fungal pathogen fusarium oxysporum initiates a necrotrophic growth phase towards the later stages of its lifecycle and is responsible for devastating fusarium wilt disease on numerous legume crops worldwide. here we describe the use of the model legume me ...201627135231
comparative genomics and prediction of conditionally dispensable sequences in legume-infecting fusarium oxysporum formae speciales facilitates identification of candidate effectors.soil-borne fungi of the fusarium oxysporum species complex cause devastating wilt disease on many crops including legumes that supply human dietary protein needs across many parts of the globe. we present and compare draft genome assemblies for three legume-infecting formae speciales (ff. spp.): f. oxysporum f. sp. ciceris (foc-38-1) and f. sp. pisi (fop-37622), significant pathogens of chickpea and pea respectively, the world's second and third most important grain legumes, and lastly f. sp. me ...201626945779
a medicago truncatula abc transporter belonging to subfamily g modulates the level of isoflavonoids.full-sized atp-binding cassette (abc) transporters of the g subfamily (abcg) are considered to be essential components of the plant immune system. these proteins have been proposed to be implicated in the active transmembrane transport of various secondary metabolites. despite the importance of abcg-based transport for plant-microbe interactions, these proteins are still poorly recognized in legumes. the experiments described here demonstrated that the level of medicago truncatula abcg10 (mtabcg ...201323314816
molecular docking of glycine max and medicago truncatula ureases with urea; bioinformatics approaches.urease (ec is a nickel-dependent metalloenzyme catalyzing the hydrolysis of urea into ammonia and carbon dioxide. it is present in many bacteria, fungi, yeasts and plants. most species, with few exceptions, use nickel metalloenzyme urease to hydrolyze urea, which is one of the commonly used nitrogen fertilizer in plant growth thus its enzymatic hydrolysis possesses vital importance in agricultural practices. considering the essentiality and importance of urea and urease activity in most ...201626852122
comparative analysis of the bacterial membrane disruption effect of two natural plant antimicrobial the medicago truncatula genome about 700 genes code for nodule-specific cysteine-rich (ncr) small peptides that are expressed in the symbiotic organ, the root nodule, where they control terminal differentiation of the endosymbiotic rhizobium bacteria to nitrogen-fixing bacteroids. cationic ncr peptides were predicted to have antimicrobial activities. here antibacterial activities of ncr247, ncr335, polymyxin b (pmb), and streptomycin were investigated and compared on two foodborne pathogens s ...201728167938
maturation of nematode-induced galls in medicago truncatula is related to water status and primary metabolism modifications.root-knot nematodes are obligatory plant parasitic worms that establish and maintain an intimate relationship with their host plants. during a compatible interaction, these nematodes induce the redifferentiation of root cells into multinucleate and hypertrophied giant cells (gcs). these metabolically active feeding cells constitute the exclusive source of nutrients for the nematode. we analyzed the modifications of water status, ionic content and accumulation of metabolites in development and ma ...201525617326
a virus inhibitory protein isolated from cyamopsis tetragonoloba (l.) taub. upon induction of systemic antiviral resistance shares partial amino acid sequence homology with a lectin.two virus inhibitory proteins were purified from cyamopsis tetragonoloba , induced to resist virus infections by cip-29, a systemic resistance inducing protein from clerodendrum inerme, and characterized. one of them shared homology with a lectin. cip-29, a known 29 kda systemic antiviral resistance inducing protein isolated from clerodendrum inerme, has been used to induce systemic resistance in cyamopsis tetragonoloba against sunn-hemp rosette virus (srv). paper reports the detection of virus ...201424828329
pseudomonas fluorescens c7r12 type iii secretion system impacts mycorrhization of medicago truncatula and associated microbial communities.type three secretion systems (t3sss) mediate cell-to-cell interactions between gram-negative bacteria and eukaryotes. we hypothesized that fluorescent pseudomonads harboring t3ss (t3ss+) would be beneficial to arbuscular mycorrhizal symbiosis because non-pathogenic fluorescent pseudomonads have been previously shown to be much more abundant in mycorrhizal than in non-mycorrhizal roots. we tested this hypothesis by comparing mycorrhization and the associated rhizosphere microbial communities of m ...201727549437
improving legume nodulation and cu rhizostabilization using a genetically modified rhizobia.the rhizobia-legume interaction has been proposed as an interesting and appropriate tool for rhizostabilization of soils contaminated with heavy metals. one of the main requirements to use this symbiosis is the availability of tolerant and symbiotically effective rhizobia. the aim of this work was to improve the symbiotic properties of the arsenic-resistant wild-type strain ensifer medicae ma11 in cu-contaminated substrates. the copab genes from a cu-resistant pseudomonas fluorescens strain were ...201525377353
effects of rhizophagus irregularis mucl 41833 on the reproduction of radopholus similis in banana plantlets grown under in vitro culture conditions.the role of arbuscular mycorrhizal fungi (amf) in the control of migratory endoparasitic nematodes is nowadays largely admitted. most studies were conducted under greenhouse conditions and a few used in vitro cultures with transgenic root organs. here, we reported, for the first time, on the interaction between an amf, rhizophagus irregularis mucl 41833 and radopholus similis in roots of banana plantlets grown under in vitro culture conditions. the banana plantlets were pre-mycorrhized in an ext ...201323111398
comparative secretome analysis of ralstonia solanacearum type 3 secretion-associated mutants reveals a fine control of effector delivery, essential for bacterial pathogenicity.ralstonia solanacearum, the causal agent of bacterial wilt, exerts its pathogenicity through more than a hundred secreted proteins, many of them depending directly on the functionality of a type 3 secretion system. to date, only few type 3 effectors have been identified as required for bacterial pathogenicity, notably because of redundancy among the large r. solanacearum effector repertoire. in order to identify groups of effectors collectively promoting disease on susceptible hosts, we investig ...201626637540
functional assignment to positively selected sites in the core type iii effector ripg7 from ralstonia solanacearum.the soil-borne pathogen ralstonia solanacearum causes bacterial wilt in a broad range of plants. the main virulence determinants of r. solanacearum are the type iii secretion system (t3ss) and its associated type iii effectors (t3es), translocated into the host cells. of the conserved t3es among r. solanacearum strains, the fbox protein ripg7 is required for r. solanacearum pathogenesis on medicago truncatula. in this work, we describe the natural ripg7 variability existing in the r. solanacearu ...201626300048
the symbiotic transcription factor mtefd and cytokinins are positively acting in the medicago truncatula and ralstonia solanacearum pathogenic interaction.• a plant-microbe dual biological system was set up involving the model legume medicago truncatula and two bacteria, the soil-borne root pathogen ralstonia solanacearum and the beneficial symbiont sinorhizobium meliloti. • comparison of transcriptomes under symbiotic and pathogenic conditions highlighted the transcription factor mtefd (ethylene response factor required for nodule differentiation) as being upregulated in both interactions, together with a set of cytokinin-related transcripts invo ...201424325235
mtqrrs1, an r-locus required for medicago truncatula quantitative resistance to ralstonia solanacearum.ralstonia solanacearum is a major soilborne pathogen that attacks > 200 plant species, including major crops. to characterize mtqrrs1, a major quantitative trait locus (qtl) for resistance towards this bacterium in the model legume medicago truncatula, genetic and functional approaches were combined. qtl analyses together with disease scoring of heterogeneous inbred families were used to define the locus. the candidate region was studied by physical mapping using a bacterial artificial chromosom ...201323638965
wheat drought-responsive wxpl transcription factors regulate cuticle biosynthesis genes.the cuticle forms a hydrophobic waxy layer that covers plant organs and provides protection from biotic and abiotic stresses. transcription of genes responsible for cuticle formation is regulated by several types of transcription factors (tfs). five orthologous to wax production (wxp1 and wxp2) genes from medicago truncatula were isolated from a cdna library prepared from flag leaves and spikes of drought tolerant wheat (triticum aestivum, breeding line rac875) and designated tawxp-like (tawxpl) ...201728161858
mtmapkk4 is an essential gene for growth and reproduction of medicago truncatula.mitogen-activated protein kinase (mapk) cascades are universal signaling modules in eukaryotes, including yeasts, animals and plants. they are involved in responses to various biotic and abiotic stresses, hormones, cell division and developmental processes. a mapk cascade is composed of three functionally tiered protein kinases, namely mapk, mapk kinases (mapkks) and mapk kinase kinases (mapkkks). these kinases have been intensively studied for their roles in developmental and physiological proc ...201727935060
genome-wide identification, evolutionary analysis and expression profiles of lateral organ boundaries domain gene family in lotus japonicus and medicago truncatula.the lateral organ boundaries domain (lbd) gene family has been well-studied in arabidopsis and play crucial roles in the diverse growth and development processes including establishment and maintenance of boundary of developmental lateral organs. in this study we identified and characterized 38 lbd genes in lotus japonicus (ljlbd) and 57 lbd genes in medicago truncatula (mtlbd), both of which are model legume plants that have some specific development features absent in arabidopsis. the phylogen ...201627560982
ripeip1, a gene from the arbuscular mycorrhizal fungus rhizophagus irregularis, is preferentially expressed in planta and may be involved in root colonization.transcriptomics and genomics data recently obtained from the arbuscular mycorrhizal (am) fungus rhizophagus irregularis have offered new opportunities to decipher the contribution of the fungal partner to the establishment of the symbiotic association. the large number of genes which do not show similarity to known proteins witnesses the uniqueness of this group of plant-associated fungi. in this work, we characterize a gene that was called ripeip1 (preferentially expressed in planta). its expre ...201627075897
proteomics and metabolomics: two emerging areas for legume improvement.the crop legumes such as chickpea, common bean, cowpea, peanut, pigeonpea, soybean, etc. are important sources of nutrition and contribute to a significant amount of biological nitrogen fixation (>20 million tons of fixed nitrogen) in agriculture. however, the production of legumes is constrained due to abiotic and biotic stresses. it is therefore imperative to understand the molecular mechanisms of plant response to different stresses and identify key candidate genes regulating tolerance which ...201526734026
regulation of anthocyanin and proanthocyanidin biosynthesis by medicago truncatula bhlh transcription factor mttt8.the myb- basic helix-loop-helix (bhlh)-wd40 complexes regulating anthocyanin and proanthocyanidin (pa) biosynthesis in plants are not fully understood. here medicago truncatula bhlh mttt8 was characterized as a central component of these ternary complexes that control anthocyanin and pa biosynthesis. mttt8 mutant seeds have a transparent testa phenotype with reduced pas and anthocyanins. mttt8 restores pa and anthocyanin productions in arabidopsis tt8 mutant. ectopic expression of mttt8 restores ...201626725247
exo70i is required for development of a sub-domain of the periarbuscular membrane during arbuscular mycorrhizal eukaryotic cells, polarized secretion mediated by exocytotic fusion of membrane vesicles with the plasma membrane is essential for spatially restricted expansion of the plasma membrane and for the delivery of molecules to specific locations at the membrane and/or cell surface. the exocyst complex is central to this process, and in yeast, regulation of the exo70 subunit influences exocytosis and cargo specificity. in contrast to yeast and mammalian cells, plants have upwards of 23 exo70 genes ...201526234213
potential regulatory phosphorylation sites in a medicago truncatula plasma membrane proton pump implicated during early symbiotic signaling in plants and fungi the plasma membrane proton pump generates a large proton-motive force that performs essential functions in many processes, including solute transport and the control of cell elongation. previous studies in yeast and higher plants have indicated that phosphorylation of an auto-inhibitory domain is involved in regulating pump activity. in this report we examine the medicago truncatula plasma membrane proton pump gene family, and in particular mtaha5. yeast complementation assay ...201526188545
cyp72a67 catalyzes a key oxidative step in medicago truncatula hemolytic saponin the medicago genus, triterpenic saponins are bioactive secondary metabolites constitutively synthesized in the aerial and subterranean parts of plants via the isoprenoid pathway. exploitation of saponins as pharmaceutics, agrochemicals and in the food and cosmetic industries has raised interest in identifying the enzymes involved in their synthesis. we have identified a cytochrome p450 (cyp72a67) involved in hemolytic sapogenin biosynthesis by a reverse genetic tilling approach in a medicago ...201526079384
itis, a bioinformatics tool for accurate identification of transposon insertion sites using next-generation sequencing data.transposable elements constitute an important part of the genome and are essential in adaptive mechanisms. transposition events associated with phenotypic changes occur naturally or are induced in insertional mutant populations. transposon mutagenesis results in multiple random insertions and recovery of most/all the insertions is critical for forward genetics study. using genome next-generation sequencing data and appropriate bioinformatics tool, it is plausible to accurately identify transposo ...201525887332
isolation and functional characterization of salt-stress induced rci2-like genes from medicago sativa and medicago truncatula.salt stress is one of the most significant adverse abiotic factors, causing crop failure worldwide. so far, a number of salt stress-induced genes, and genes improving salt tolerance have been characterized in a range of plants. here, we report the isolation and characterization of a salt stress-induced medicago sativa (alfalfa) gene (msrci2a), which showed a high similarity to the yeast plasma membrane protein 3 gene (pmp3) and arabidopsis rci2a. the sequence comparisons revealed that five genes ...201525801273
unraveling the triterpenoid saponin biosynthesis of the african shrub maesa lanceolata.maesasaponins produced by the african shrub maesa lanceolata are oleanane-type saponins with diverse biological activities. through a combination of transcript profiling of methyl jasmonate-elicited m. lanceolata shoot cultures, functional analysis in transgenic m. lanceolata plants and the heterologous hosts medicago truncatula and saccharomyces cerevisiae, we identified three maesaponin biosynthesis genes. these include a β-amyrin synthase and two cytochrome p450s, cyp716a75 and cyp87d16, whic ...201525578277
comparative analysis of cyp93e proteins for improved microbial synthesis of plant triterpenoids.cytochrome p450-dependent monooxygenases (p450s) belonging to the cyp93e subfamily catalyze the c-24 oxidation of the triterpene backbone during the biosynthesis of triterpenoid saponins, which are bioactive plant natural products. in our attempts to produce plant triterpenoids in the yeast saccharomyces cerevisiae, we observed a poor in vivo catalytic efficiency of the medicago truncatula cyp93e2. to overcome this biosynthetic bottleneck, we screened publicly available plant genome and transcri ...201425453910
an in planta-expressed polyketide synthase produces (r)-mellein in the wheat pathogen parastagonospora nodorum.parastagonospora nodorum is a pathogen of wheat that affects yields globally. previous transcriptional analysis identified a partially reducing polyketide synthase (pr-pks) gene, snog_00477 (sn477), in p. nodorum that is highly upregulated during infection of wheat leaves. disruption of the corresponding sn477 gene resulted in the loss of production of two compounds, which we identified as (r)-mellein and (r)-o-methylmellein. using a saccharomyces cerevisiae yeast heterologous expression system, ...201525326302
unravelling the triterpenoid saponin biosynthesis of the african shrub maesa lanceolata.maesasaponins produced by the african shrub maesa lanceolata are oleanane-type saponins with diverse biological activities. candidate maesasaponin biosynthesis genes were identified through transcript profiling of m. lanceolata shoot cultures treated with methyl jasmonate, a well-known elicitor of plant specialized metabolism. heterologous expression of the identified genes in saccharomyces cerevisiae led to the identification of one oxidosqualene cyclase (mlbas) and two cytochrome p450s, cyp716 ...201425296856
[optimization of synthetic pathway and fermentation process of yeast cell factories for production of oleanoic acid].to optimize the synthetic pathway and fermentation process of yeast cell factories for production of oleanoic acid.201425272488
a nitrogen-dependent switch in the high affinity ammonium transport in medicago truncatula.ammonium transporters (amts) are crucial for the high affinity primary uptake and translocation of ammonium in plants. in the model legume medicago truncatula, the genomic set of amt-type ammonium transporters comprises eight members. only four genes were abundantly expressed in young seedlings, both in roots and shoots. while the expression of all amts in the shoot was not affected by the nitrogen availability, the dominating mtamt1;1 gene was repressed by nitrogen in roots, despite that cellul ...201425164101
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