| transgenic overexpression of the transcription factor alfin1 enhances expression of the endogenous msprp2 gene in alfalfa and improves salinity tolerance of the plants | alfin1 cdna encodes a putative transcription factor associated with nacl tolerance in alfalfa (medicago sativa l.). the recombinant protein binds dna in a sequence-specific manner, including promoter fragments of the nacl-inducible gene msprp2. alfin1 function was tested in transgenic alfalfa under the control of the 35s promoter in the sense and antisense orientations with the endogenous msprp2 as a reporter gene. calli overexpressing alfin1 were more resistant to growth inhibition by 171 mm na ... | 1999 | 10364398 |
| winter survival of transgenic alfalfa overexpressing superoxide dismutase | to test the hypothesis that enhanced tolerance of oxidative stress would improve winter survival, two clones of alfalfa (medicago sativa) were transformed with a mn-superoxide dismutase (mn-sod) targeted to the mitochondria or to the chloroplast. although mn-sod activity increased in most primary transgenic plants, both cytosolic and chloroplastic forms of cu/zn-sod had lower activity in the chloroplast sod transgenic plants than in the nontransgenic plants. in a field trial at elora, ontario, c ... | 1999 | 10069823 |
| iron-superoxide dismutase expression in transgenic alfalfa increases winter survival without a detectable increase in photosynthetic oxidative stress tolerance. | to determine whether overexpression of fe-superoxide (sod) dismutase would increase superoxide-scavenging capacity and thereby improve the winter survival of transgenic alfalfa (medicago sativa l.) plants, two genotypes were transformed with the vector pexsod10, which contains a cdna for arabidopsis fe-sod with a chloroplast transit peptide and cauliflower mosaic virus 35s promoter. a novel fe-sod was detected by native page in both greenhouse- and field-grown transgenic plants, but activity var ... | 2000 | 10759538 |
| constitutive overexpression of cytosolic glutamine synthetase (gs1) gene in transgenic alfalfa demonstrates that gs1 may be regulated at the level of rna stability and protein turnover. | glutamine synthetase (gs) catalyzes the atp-dependent condensation of nh4+ with glutanate to yield glutamine. gene constructs consisting of the cauliflower mosaic virus (camv) 35s promoter driving a cytosolic isoform of gs (gs1) gene have been introduced into alfalfa (medicago sativa). although transcripts for the transgene were shown to accumulate to high levels in the leaves, they were undetectable in the nodules. however, significant amounts of beta-glucuronidase activity could be detected in ... | 2001 | 11351075 |
| downregulation of caffeic acid 3-o-methyltransferase and caffeoyl coa 3-o-methyltransferase in transgenic alfalfa. impacts on lignin structure and implications for the biosynthesis of g and s lignin. | transgenic alfalfa plants were generated harboring caffeic acid 3-o-methyltransferase (comt) and caffeoyl coa 3-o-methyltransferase (ccomt) cdna sequences under control of the bean phenylalanine ammonia-lyase pal2 promoter. strong downregulation of comt resulted in decreased lignin content, a reduction in total guaiacyl (g) lignin units, a near total loss of syringyl (s) units in monomeric and dimeric lignin degradation products, and appearance of low levels of 5-hydroxy guaiacyl units and a nov ... | 2001 | 11158530 |
| bottlenecks for metabolic engineering of isoflavone glycoconjugates in arabidopsis. | in view of their perceived chemopreventive activities against hormone-dependent cancers, cardiovascular disease, and postmenopausal ailments, there is considerable interest in engineering plants to contain isoflavone phytoestrogens. however, attempts to date have only resulted in low levels of isoflavone accumulation in non-legumes. introducing soybean isoflavone synthase (ifs) into arabidopsis thaliana leads to accumulation of low levels of genistein glycosides. leaves of wild-type a. thaliana ... | 2002 | 12384577 |
| the molecular genetic linkage map of the model legume medicago truncatula: an essential tool for comparative legume genomics and the isolation of agronomically important genes. | the legume medicago truncatula has emerged as a model plant for the molecular and genetic dissection of various plant processes involved in rhizobial, mycorrhizal and pathogenic plant-microbe interactions. aiming to develop essential tools for such genetic approaches, we have established the first genetic map of this species. two parental homozygous lines were selected from the cultivar jemalong and from the algerian natural population (dza315) on the basis of their molecular and phenotypic poly ... | 2002 | 11825338 |
| altered life cycle in arabidopsis plants expressing psugt1, a udp-glucuronosyltransferase-encoding gene from pea. | alfalfa (medicago sativa) and arabidopsis were used as model systems to examine molecular mechanisms underlying developmental effects of a microsomal udp-glucuronosyltransferase-encoding gene from pea (pisum sativum; psugt1). alfalfa expressing psugt1 antisense mrna under the control of the cauliflower mosaic virus (camv) 35s promoter exhibited delayed root emergence, reduced root growth, and increased lateral root development. the timing of root emergence in wild-type and antisense plants was c ... | 2003 | 12972656 |
| expression of anthocyanins and proanthocyanidins after transformation of alfalfa with maize lc. | three anthocyanin regulatory genes of maize (zea mays; lc, b-peru, and c1) were introduced into alfalfa (medicago sativa) in a strategy designed to stimulate the flavonoid pathway and alter the composition of flavonoids produced in forage. lc constructs included a full-length gene and a gene with a shortened 5'-untranslated region. lc rna was strongly expressed in lc transgenic alfalfa foliage, but accumulation of red-purple anthocyanin was observed only under conditions of high light intensity ... | 2003 | 12857826 |
| the medicago species a2-type cyclin is auxin regulated and involved in meristem formation but dispensable for endoreduplication-associated developmental programs. | phytohormones as well as temporal and spatial regulation of the cell cycle play a key role in plant development. here, we investigated the function and regulation of an alfalfa (medicago sativa) a2-type cyclin in three distinct root developmental programs: in primary and secondary root development, nodule development, and nematode-elicited gall formation. using transgenic plants carrying the medsa;cyca2;2 promoter-beta-glucuronidase gene fusion, in combination with other techniques, cyca2;2 expr ... | 2003 | 12644661 |
| biochemical and molecular characterization of transgenic lotus japonicus plants constitutively over-expressing a cytosolic glutamine synthetase gene. | higher plants assimilate nitrogen in the form of ammonia through the concerted activity of glutamine synthetase (gs) and glutamate synthase (gogat). the gs enzyme is either located in the cytoplasm (gs1) or in the chloroplast (gs2). to understand how modulation of gs activity affects plant performance, lotus japonicus l. plants were transformed with an alfalfa gs1 gene driven by the camv 35s promoter. the transformants showed increased gs activity and an increase in gs1 polypeptide level in all ... | 2004 | 15197594 |
| targeted down-regulation of cytochrome p450 enzymes for forage quality improvement in alfalfa (medicago sativa l.). | improving the digestibility of forages provides a means to enhance animal performance and protect the environment against excessive animal waste. increased lignin content during maturity, and corresponding changes in lignin composition, correlate with decreased digestibility of forages. these relationships have yet to be investigated in isogenic systems. by targeting three specific cytochrome p450 enzymes of the lignin pathway for antisense down-regulation, we generated transgenic alfalfa lines ... | 2005 | 16263933 |
| mitosis-specific promoter of the alfalfa cyclin-dependent kinase gene (medsa;cdkb2;1) is activated by wounding and ethylene in a non-cell division-dependent manner. | cyclin-dependent serine/threonine kinases (cdks) have pivotal roles in regulating the eukaryotic cell cycle. plants possess a unique class of cdks (b-type cdks) with preferential protein accumulation at g2/m-phases; however, their exact functions are still enigmatic. here we describe the functional characterization of a 360-bp promoter region of the alfalfa (medicago sativa) cdkb2;1 gene in transgenic plants and cell lines. it is shown that the activity of the analyzed promoter was characteristi ... | 2006 | 16407448 |
| compound leaf development and evolution in the legumes. | across vascular plants, class 1 knotted1-like (knox1) genes appear to play a critical role in the development of compound leaves. an exception to this trend is found in the fabaceae, where pea (pisum sativum) uses unifoliata, an ortholog of the floral regulators floricaula (flo) and leafy (lfy), in place of knox1 genes to regulate compound leaf development. to assess the phylogenetic distribution of knox1-independent compound leaf development, a survey of knox1 protein expression across the faba ... | 2007 | 17993625 |
| comparative genomic sequence and expression analyses of medicago truncatula and alfalfa subspecies falcata cold-acclimation-specific genes. | in arabidopsis (arabidopsis thaliana) the low-temperature induction of genes encoding the c-repeat binding factor (cbf) transcriptional activators is a key step in cold acclimation. cbfs in turn activate a battery of downstream genes known as the cbf regulon, which collectively act to increase tolerance to low temperatures. fundamental questions are: what determines the size and scope of the cbf regulon, and is this is a major determinant of the low-temperature tolerance capacity of individual p ... | 2008 | 18218976 |
| 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 |
| repercussion of mesophyll-specific overexpression of a soybean cytosolic glutamine synthetase gene in alfalfa (medicago sativa l.) and tobacco (nicotiana tabaccum l.). | glutamine synthetase (gs) plays a central role in plant nitrogen metabolism. plant gs occurs as a number of isoenzymes present in either the cytosol (gs1) or chloroplast/plastid (gs2). there are several reports of improved performance in transgenic plants overexpressing gs1 transgenes driven by the constitutive camv35s promoter. improvement has been attributed to the gs1 transgene product functioning to enhance re-assimilation of nh4(+) released by photorespiration or protein degradation. in thi ... | 2009 | 25067868 |
| a plastid-localized glycogen synthase kinase 3 modulates stress tolerance and carbohydrate metabolism. | glycogen synthase kinase 3 (gsk-3) was originally identified as a regulator of glycogen synthesis in mammals. like starch in plants, glycogen is a polymer of glucose, and serves as an energy and carbon store. starch is the main carbohydrate store in plants. regulation of starch metabolism, in particular in response to environmental cues, is of primary importance for carbon and energy flow in plants but is still obscure. here, we provide evidence that msk4, a novel medicago sativa gsk-3-like kina ... | 2007 | 17319843 |
| silencing of the rac1 gtpase mtrop9 in medicago truncatula stimulates early mycorrhizal and oomycete root colonizations but negatively affects rhizobial infection. | rac/rop proteins (ρ-related gtpases of plants) are plant-specific small g proteins that function as molecular switches within elementary signal transduction pathways, including the regulation of reactive oxygen species (ros) generation during early microbial infection via the activation of nadph oxidase homologs of plants termed rboh (for respiratory burst oxidase homolog). we investigated the role of medicago truncatula jemalong a17 small gtpase mtrop9, orthologous to medicago sativa rac1, via ... | 2012 | 22399646 |
| mtpar myb transcription factor acts as an on switch for proanthocyanidin biosynthesis in medicago truncatula. | mtpar (medicago truncatula proanthocyanidin regulator) is an myb family transcription factor that functions as a key regulator of proanthocyanidin (pa) biosynthesis in the model legume medicago truncatula. mtpar expression is confined to the seed coat, the site of pa accumulation. loss-of-function par mutants contained substantially less pa in the seed coat than the wild type, whereas levels of anthocyanin and other specialized metabolites were normal in the mutants. in contrast, massive accumul ... | 2012 | 22307644 |
| medicago truncatula gaertn. as a model for understanding the mechanism of growth promotion by bacteria from rhizosphere and nodules of alfalfa. | the present study showed all the 16 strains isolated and identified from the alfalfa rhizosphere and nodules, and registered in genbank, to be good candidates for targeted use in studies addressing the rather weak known mechanism of plant growth promotion, including that of medicago truncatula, a molecular crop model. based on physiological, biochemical and molecular analysis, the 16 isolates obtained were ascribed to the following five families: bacillaceae, rhizobiaceae, xantomonadaceae, enter ... | 2016 | 26861677 |
| metabolic engineering of proanthocyanidin production by repressing the isoflavone pathways and redirecting anthocyanidin precursor flux in legume. | mtpar is a proanthocyanidin (pa) biosynthesis regulator; the mechanism underlying its promotion of pa biosynthesis is not fully understood. here, we showed that mtpar promotes pa production by a direct repression of biosynthesis of isoflavones, the major flavonoids in legume, and by redirecting immediate precursors, such as anthocyanidins, flux into pa pathway. ectopic expression of mtpar repressed isoflavonoid production by directly binding and suppressing isoflavone biosynthetic genes such as ... | 2016 | 26806316 |
| antioxidant defenses in the peripheral cell layers of legume root nodules. | ascorbate peroxidase (ap) is a key enzyme that scavenges potentially harmful h2o2 and thus prevents oxidative damage in plants, especially in n2-fixing legume root nodules. the present study demonstrates that the nodule endodermis of alfalfa (medicago sativa) root nodules contains elevated levels of ap protein, as well as the corresponding mrna transcript and substrate (ascorbate). enhanced ap protein levels were also found in cells immediately peripheral to the infected region of soybean (glyci ... | 1998 | 9449834 |
| 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 |
| effects of engineered sinorhizobium meliloti on cytokinin synthesis and tolerance of alfalfa to extreme drought stress. | cytokinin is required for the initiation of leguminous nitrogen fixation nodules elicited by rhizobia and the delay of the leaf senescence induced by drought stress. a few free-living rhizobia have been found to produce cytokinin. however, the effects of engineered rhizobia capable of synthesizing cytokinin on host tolerance to abiotic stresses have not yet been described. in this study, two engineered sinorhizobium strains overproducing cytokinin were constructed. the tolerance of inoculated al ... | 2012 | 22961897 |
| in silico insights into the symbiotic nitrogen fixation in sinorhizobium meliloti via metabolic reconstruction. | sinorhizobium meliloti is a soil bacterium, known for its capability to establish symbiotic nitrogen fixation (snf) with leguminous plants such as alfalfa. s. meliloti 1021 is the most extensively studied strain to understand the mechanism of snf and further to study the legume-microbe interaction. in order to provide insight into the metabolic characteristics underlying the snf mechanism of s. meliloti 1021, there is an increasing demand to reconstruct a metabolic network for the stage of snf i ... | 2012 | 22319621 |
| comparative genomics of the core and accessory genomes of 48 sinorhizobium strains comprising five genospecies. | the sinorhizobia are amongst the most well studied members of nitrogen-fixing root nodule bacteria and contribute substantial amounts of fixed nitrogen to the biosphere. while the alfalfa symbiont sinorhizobium meliloti rm 1021 was one of the first rhizobial strains to be completely sequenced, little information is available about the genomes of this large and diverse species group. | 2013 | 23425606 |
| ectopic expression of mir156 represses nodulation and causes morphological and developmental changes in lotus japonicus. | the effects of microrna156 overexpression on general plant architecture, branching, flowering time and nodulation were investigated in the model legume, lotus japonicus. we cloned an mir156 homolog, ljmir156a, from l. japonicus, and investigated its squamosa promoter binding protein like (spl) genes and its biological function at enhancing vegetative biomass yield, extending flowering time, and its impact on nodulation. thirteen potential targets for ljmir156 were identified in vitro and their e ... | 2014 | 25293935 |
| transcriptional regulator lsrb of sinorhizobium meliloti positively regulates the expression of genes involved in lipopolysaccharide biosynthesis. | rhizobia induce nitrogen-fixing nodules on host legumes, which is important in agriculture and ecology. lipopolysaccharide (lps) produced by rhizobia is required for infection or bacteroid survival in host cells. genes required for lps biosynthesis have been identified in several rhizobium species. however, the regulation of their expression is not well understood. here, sinorhizobium meliloti lsrb, a member of the lysr family of transcriptional regulators, was found to be involved in lps biosyn ... | 2014 | 24951786 |
| cell growth inhibition upon deletion of four toxin-antitoxin loci from the megaplasmids of sinorhizobium meliloti. | toxin and antitoxin (ta) gene pairs are addiction systems that are present in many microbial genomes. sinorhizobium meliloti is an n2-fixing bacterial symbiont of alfalfa and other leguminous plants, and its genome consists of three large replicons, a circular chromosome (3.7 mb) and the megaplasmids psyma (1.4 mb) and psymb (1.7 mb). s. meliloti carries 211 predicted type ii ta genes, each encoding a toxin or an antitoxin. we constructed defined deletion strains that collectively removed the en ... | 2014 | 24317400 |
| nodulation by sinorhizobium meliloti originated from a mining soil alleviates cd toxicity and increases cd-phytoextraction in medicago sativa l. | besides their role in nitrogen supply to the host plants as a result of symbiotic n fixation, the association between legumes and rhizobium could be useful for the rehabilitation of metal-contaminated soils by phytoextraction. a major limitation presents the metal-sensitivity of the bacterial strains. the aim of this work was to explore the usefulness of sinorhizobium meliloti originated from a mining site for cd phytoextraction by medicago sativa. inoculated and non-inoculated plants were culti ... | 2015 | 26528320 |
| biofilm formation assessment in sinorhizobium meliloti reveals interlinked control with surface motility. | swarming motility and biofilm formation are opposite, but related surface-associated behaviors that allow various pathogenic bacteria to colonize and invade their hosts. in sinorhizobium meliloti, the alfalfa endosymbiont, these bacterial processes and their relevance for host plant colonization are largely unexplored. our previous work demonstrated distinct swarming abilities in two s. meliloti strains (rm1021 and gr4) and revealed that both environmental cues (iron concentration) and bacterial ... | 2015 | 25887945 |
| oxygen regulation of a nodule-located carbonic anhydrase in alfalfa. | control of the permeability to oxygen is critical for the function of symbiotic nitrogen fixation in legume nodules. the inner cortex (ic) seems to be a primary site for this regulation. in alfalfa (medicago sativa) nodules, expression of the msca1 gene encoding a carbonic anhydrase (ca) was previously found to be restricted to the ic. we have now raised antibodies against recombinant msca1 protein and used them, together with antibodies raised against potato leaf ca, to demonstrate the presence ... | 2000 | 11080283 |
| genome sequence of the symbiotic type strain rhizobium tibeticum ccbau85039t. | rhizobium tibeticum was originally isolated from root nodules of trigonella archiducis-nicolai grown in tibet, china. this species is also able to nodulate medicago sativa and phaseolus vulgaris the whole-genome sequence of the type strain, r. tibeticum ccbau85039(t), is reported in this study. | 2017 | 28126941 |
| elevation of the cytosolic free [ca2+] is indispensable for the transduction of the nod factor signal in alfalfa. | in root hairs of alfalfa (medicago sativa), the requirement of ca(2+) for nod factor signaling has been investigated by means of ion-selective microelectrodes. measured 50 to 100 microm behind the growing tip, 0.1 microm nodrm-iv(c16:2,s) increased the cytosolic free [ca2+] by about 0.2 pca, while the same concentration of chitotetraose, the nonactive glucosamine backbone, had no effect. we demonstrate that nodrm-iv(c16:2,s) still depolarized the plasma membrane at external ca(2+) concentrations ... | 1999 | 10482683 |
| nadh-glutamate synthase in alfalfa root nodules. immunocytochemical localization | in root nodules of alfalfa (medicago sativa l.), n2 is reduced to nh4+ in the bacteroid by the nitrogenase enzyme and then released into the plant cytosol. the nh4+ is then assimilated by the combined action of glutamine synthetase (ec 6.3.1.2) and nadh-dependent glu synthase (nadh-gogat; ec 1.4.1.14) into glutamine and glu. the alfalfa nodule nadh-gogat protein has a 101-amino acid presequence, but the subcellular location of the protein is unknown. using immunocytochemical localization, we det ... | 1999 | 10069822 |
| glycolytic flux is adjusted to nitrogenase activity in nodules of detopped and argon-treated alfalfa plants | to investigate the short-term (30-240 min) interactions among nitrogenase activity, nh4+ assimilation, and plant glycolysis, we measured the concentrations of selected c and n metabolites in alfalfa (medicago sativa l.) root nodules after detopping and during continuous exposure of the nodulated roots to ar:o2 (80:20, v/v). both treatments caused an increase in the ratios of glucose-6-phosphate to fructose-1,6-bisphosphate, fructose-6-phosphate to fructose-1,6-bisphosphate, phosphoenolpyruvate ( ... | 1999 | 9952439 |
| how alfalfa root hairs discriminate between nod factors and oligochitin elicitors. | using ion-selective microelectrodes, the problem of how signals coming from symbiotic partners or from potential microbial intruders are distinguished was investigated on root hairs of alfalfa (medicago sativa). the nod factor, nodrm-iv(c16:2,s), was used to trigger the symbiotic signal and (glcnac)(8) was selected from (glcnac)(4-8), to elicit defense-related reactions. to both compounds, root hairs responded with initial transient depolarizations and alkalinizations, which were followed by a h ... | 2000 | 11080312 |
| accumulation of enod2-like transcripts in non-nodulating woody papilionoid legumes. | japanese pagodatree (styphnolobium japonicum [l.] schott) and american yellowwood (cladrastis kentukea dum.-cours.) rudd are the first woody, non-nodulating papilionoid legumes shown to possess putative early nodulin 2 (enod2) genes. enod2 cdnas from japanese pagodatree (807 bp) and american yellowwood (735 bp) have 75% to 79% sequence identity to enod2 sequences and encode deduced proteins that possess conserved enod2 pentapeptides (pphek and ppeyq). lower percentages of glucose and higher perc ... | 2000 | 11027723 |
| variation of microbial communities in soil, rhizosphere, and rhizoplane in response to crop species, soil type, and crop development. | we investigated the influence of plant species, soil type, and plant development time on the shaping of microbial communities in soil and in association with roots. the sample group consisted of a total of 32 microcosms in three habitats: soil, rhizosphere, and rhizoplane. communities were represented by the patterns of a sequence-specific separation of rrna target sequences. effects of experimental parameters were classified by a cluster analysis of pattern similarities. the type of plant speci ... | 2001 | 11722945 |
| translational and structural requirements of the early nodulin gene enod40, a short-open reading frame-containing rna, for elicitation of a cell-specific growth response in the alfalfa root cortex. | a diversity of mrnas containing only short open reading frames (sorf-rnas; encoding less than 30 amino acids) have been shown to be induced in growth and differentiation processes. the early nodulin gene enod40, coding for a 0.7-kb sorf-rna, is expressed in the nodule primordium developing in the root cortex of leguminous plants after infection by symbiotic bacteria. ballistic microtargeting of this gene into medicago roots induced division of cortical cells. translation of two sorfs (i and ii, ... | 2001 | 11113209 |
| proline betaine accumulation and metabolism in alfalfa plants under sodium chloride stress. exploring its compartmentalization in nodules. | the osmoprotectant pro betaine is the main betaine identified in alfalfa (medicago sativa). we have investigated the long-term responses of nodulated alfalfa plants to salt stress, with a particular interest for pro betaine accumulation, compartmentalization, and metabolism. exposure of 3-week-old nodulated alfalfa plants to 0.2 m nacl for 4 weeks was followed by a 10-, 4-, and 8-fold increase in pro betaine in shoots, roots, and nodules, respectively. isotope-labeling studies in alfalfa shoots ... | 2004 | 15235114 |
| elevated co2 concentration around alfalfa nodules increases n2 fixation. | nodule co2 fixation via pepc provides malate for bacteroids and oxaloacetate for n assimilation. the process is therefore of central importance for efficient nitrogen fixation. nodule co2 fixation is known to depend on external co2 concentration. the hypothesis of the present paper was that nitrogen fixation in alfalfa plants is enhanced when the nodules are exposed to elevated co2 concentrations. therefore nodulated plants of alfalfa were grown in a hydroponic system that allowed separate aerat ... | 2009 | 19815686 |
| comparative gene expression profiles between heterotic and non-heterotic hybrids of tetraploid medicago sativa. | heterosis, the superior performance of hybrids relative to parents, has clear agricultural value, but its genetic control is unknown. our objective was to test the hypotheses that hybrids expressing heterosis for biomass yield would show more gene expression levels that were different from midparental values and outside the range of parental values than hybrids that do not exhibit heterosis. | 2009 | 19678936 |
| plant physiology and proteomics reveals the leaf response to drought in alfalfa (medicago sativa l.). | despite its relevance, protein regulation, metabolic adjustment, and the physiological status of plants under drought is not well understood in relation to the role of nitrogen fixation in nodules. in this study, nodulated alfalfa plants were exposed to drought conditions. the study determined the physiological, metabolic, and proteomic processes involved in photosynthetic inhibition in relation to the decrease in nitrogenase (n(ase)) activity. the deleterious effect of drought on alfalfa perfor ... | 2010 | 20797998 |
| transcript profiling of two alfalfa genotypes with contrasting cell wall composition in stems using a cross-species platform: optimizing analysis by masking biased probes. | the genechip(r) medicago genome array, developed for medicago truncatula, is a suitable platform for transcript profiling in tetraploid alfalfa [medicago sativa (l.) subsp. sativa]. however, previous research involving cross-species hybridization (csh) has shown that sequence variation between two species can bias transcript profiling by decreasing sensitivity (number of expressed genes detected) and the accuracy of measuring fold-differences in gene expression. | 2010 | 20497574 |
| the medicago genome provides insight into the evolution of rhizobial symbioses. | legumes (fabaceae or leguminosae) are unique among cultivated plants for their ability to carry out endosymbiotic nitrogen fixation with rhizobial bacteria, a process that takes place in a specialized structure known as the nodule. legumes belong to one of the two main groups of eurosids, the fabidae, which includes most species capable of endosymbiotic nitrogen fixation. legumes comprise several evolutionary lineages derived from a common ancestor 60 million years ago (myr ago). papilionoids ar ... | 2011 | 22089132 |
| characterization of the twin-arginine transport secretome in sinorhizobium meliloti and evidence for host-dependent phenotypes. | the twin-arginine transport (tat) system is essential for cell viability in sinorhizobium meliloti and may play a role during the development of root nodules. utilizing an in vivo recombination strategy, we have constructed 28 strains that contain deletions in predicted tat substrates. testing of these mutations for symbiotic proficiency on the plant hosts alfalfa and sweet clover shows that some of these mutations affect associations with these hosts differentially. | 2012 | 22843517 |
| 'ca. liberibacter asiaticus' proteins orthologous with psyma-encoded proteins of sinorhizobium meliloti: hypothetical roles in plant host interaction. | sinorhizobium meliloti strain 1021, a nitrogen-fixing, root-nodulating bacterial microsymbiont of alfalfa, has a 3.5 mbp circular chromosome and two megaplasmids including 1.3 mbp psyma carrying nonessential 'accessory' genes for nitrogen fixation (nif), nodulation and host specificity (nod). a related bacterium, psyllid-vectored 'ca. liberibacter asiaticus,' is an obligate phytopathogen with a reduced genome that was previously analyzed for genes orthologous to genes on the s. meliloti circular ... | 2012 | 22761700 |
| exploring the plant-associated bacterial communities in medicago sativa l. | plant-associated bacterial communities caught the attention of several investigators which study the relationships between plants and soil and the potential application of selected bacterial species in crop improvement and protection. medicago sativa l. is a legume crop of high economic importance as forage in temperate areas and one of the most popular model plants for investigations on the symbiosis with nitrogen fixing rhizobia (mainly belonging to the alphaproteobacterial species sinorhizobi ... | 2012 | 22607312 |
| desiccation induces viable but non-culturable cells in sinorhizobium meliloti 1021. | sinorhizobium meliloti is a microorganism commercially used in the production of e.g. medicago sativa seed inocula. many inocula are powder-based and production includes a drying step. although s. meliloti survives drying well, the quality of the inocula is reduced during this process. in this study we determined survival during desiccation of the commercial strains 102f84 and 102f85 as well as the model strain usda1021.the survival of s. meliloti 1021 was estimated during nine weeks at 22% rela ... | 2012 | 22260437 |
| genome sequence of ensifer meliloti strain wsm1022; a highly effective microsymbiont of the model legume medicago truncatula a17. | ensifer meliloti wsm1022 is an aerobic, motile, gram-negative, non-spore-forming rod that can exist as a soil saprophyte or as a legume microsymbiont of medicago. wsm1022 was isolated in 1987 from a nodule recovered from the roots of the annual medicago orbicularis growing on the cyclades island of naxos in greece. wsm1022 is highly effective at fixing nitrogen with m. truncatula and other annual species such as m. tornata and m. littoralis and is also highly effective with the perennial m. sati ... | 2013 | 24976888 |
| the divj, cbra and plec system controls divk phosphorylation and symbiosis in sinorhizobium meliloti. | sinorhizobium meliloti is a soil bacterium that invades the root nodules it induces on medicago sativa, whereupon it undergoes an alteration of its cell cycle and differentiates into nitrogen-fixing, elongated and polyploid bacteroid with higher membrane permeability. in caulobacter crescentus, a related alphaproteobacterium, the principal cell cycle regulator, ctra, is inhibited by the phosphorylated response regulator divk. the phosphorylation of divk depends on the histidine kinase divj, whil ... | 2013 | 23909720 |
| comparative analysis of the symbiotic efficiency of medicago truncatula and medicago sativa under phosphorus deficiency. | phosphorus (p)-deficiency is a major abiotic stress that limits legume growth in many types of soils. the relationship between medicago and sinorhizobium, is known to be affected by different environmental conditions. recent reports have shown that, in combination with s. meliloti 2011, medicago truncatula had a lower symbiotic efficiency than medicago sativa. however, little is known about how medicago-sinorhizobium is affected by p-deficiency at the whole-plant level. the objective of the pres ... | 2013 | 23459233 |
| directed construction and analysis of a sinorhizobium meliloti psyma deletion mutant library. | resources from the sinorhizobium meliloti rm1021 open reading frame (orf) plasmid libraries were used in a medium-throughput method to construct a set of 50 overlapping deletion mutants covering all of the rm1021 psyma megaplasmid except the replicon region. each resulting psyma derivative carried a defined deletion of approximately 25 orfs. various phenotypes, including cytochrome c respiration activity, the ability of the mutants to grow on various carbon and nitrogen sources, and the symbioti ... | 2013 | 23335760 |
| concerted changes in n and c primary metabolism in alfalfa (medicago sativa) under water restriction. | although the mechanisms of nodule n(2) fixation in legumes are now well documented, some uncertainty remains on the metabolic consequences of water deficit. in most cases, little consideration is given to other organs and, therefore, the coordinated changes in metabolism in leaves, roots, and nodules are not well known. here, the effect of water restriction on exclusively n(2)-fixing alfalfa (medicago sativa l.) plants was investigated, and proteomic, metabolomic, and physiological analyses were ... | 2013 | 23440170 |
| complete genome sequence of the alfalfa symbiont sinorhizobium/ensifer meliloti strain gr4. | we present the complete nucleotide sequence of the multipartite genome of sinorhizobium/ensifer meliloti gr4, a predominant rhizobial strain in an agricultural field site. the genome (total size, 7.14 mb) consists of five replicons: one chromosome, two expected symbiotic megaplasmids (prmegr4c and prmegr4d), and two accessory plasmids (prmegr4a and prmegr4b). | 2013 | 23409262 |
| genome sequence of sinorhizobium meliloti rm41. | sinorhizobium meliloti rm41 nodulates alfalfa plants, forming indeterminate type nodules. it is characterized by a strain-specific k-antigen able to replace exopolysaccharides in promotion of nodule invasion. we present the rm41 genome, composed of one chromosome, the chromid psymb, the megaplasmid psyma, and the nonsymbiotic plasmid prme41a. | 2013 | 23405285 |
| a comparison of the retention of pathogenic escherichia coli o157 by sprouts, leaves and fruits. | the retention (binding to or association with the plant) of escherichia coli by cut leaves and fruits after vigorous water washing was compared with that by sprouts. retention by fruits and leaves was similar but differed from retention by sprouts in rate, effect of wounding and requirement for poly-β,1-6-n-acetyl-d-glucosamine. escherichia coli was retained by cut ends of lettuce leaves within 5 min while more than 1 h was required for retention by the intact epidermis of leaves and fruits, and ... | 2014 | 25351040 |
| micromonospora from nitrogen fixing nodules of alfalfa (medicago sativa l.). a new promising plant probiotic bacteria. | biotic interactions can improve agricultural productivity without costly and environmentally challenging inputs. micromonospora strains have recently been reported as natural endophytes of legume nodules but their significance for plant development and productivity has not yet been established. the aim of this study was to determine the diversity and function of micromonospora isolated from medicago sativa root nodules. micromonospora-like strains from field alfalfa nodules were characterized by ... | 2014 | 25227415 |
| evaluation of alfalfa inter-seeding effect on bahiagrass baleage fermentation and lactating holstein performance. | previous research indicates that bahiagrass may be successfully conserved as baleage, but nutritive value is typically low for lactating dairy cows. the purpose of this study was to determine the effect of adding modest amounts of alfalfa forage (22%), achieved by inter-seeding alfalfa into an existing bahiagrass pasture, on baleage nutritive value and lactation performance of holstein cows. forage treatments employed were monoculture bahiagrass baleage (mbb; negative control), bahiagrass-alfalf ... | 2014 | 25143823 |
| assessment of the soil organic carbon sink in a project for the conversion of farmland to forestland: a case study in zichang county, shaanxi, china. | the conversion of farmland to forestland not only changes the ecological environment but also enriches the soil with organic matter and affects the global carbon cycle. this paper reviews the influence of land use changes on the soil organic carbon sink to determine whether the chinese "grain-for-green" (conversion of farmland to forestland) project increased the rate of soc content during its implementation between 1999 and 2010 in the hilly and gully areas of the loess plateau in north-central ... | 2014 | 24736591 |
| 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 ... | 2014 | 25197447 |
| lignin modification leads to increased nodule numbers in alfalfa. | reduction of lignin levels in the forage legume alfalfa (medicago sativa) by down-regulation of the monolignol biosynthetic enzyme hydroxycinnamoyl coenzyme a:shikimate hydroxycinnamoyl transferase (hct) results in strongly increased digestibility and processing ability of lignocellulose. however, these modifications are often also associated with dwarfing and other changes in plant growth. given the importance of nitrogen fixation for legume growth, we evaluated the impact of constitutively tar ... | 2014 | 24406794 |
| transgene silencing of sucrose synthase in alfalfa (medicago sativa l.) stem vascular tissue suggests a role for invertase in cell wall cellulose synthesis. | alfalfa (medicago sativa l.) is a widely adapted perennial forage crop that has high biomass production potential. enhanced cellulose content in alfalfa stems would increase the value of the crop as a bioenergy feedstock. we examined if increased expression of sucrose synthase (sus; ec 2.4.1.13) would increase cellulose in stem cell walls. | 2015 | 26627884 |
| an empirical model that uses light attenuation and plant nitrogen status to predict within-canopy nitrogen distribution and upscale photosynthesis from leaf to whole canopy. | modelling the spatial and temporal distribution of leaf nitrogen (n) is central to specify photosynthetic parameters and simulate canopy photosynthesis. leaf photosynthetic parameters depend on both local light availability and whole-plant n status. the interaction between these two levels of integration has generally been modelled by assuming optimal canopy functioning, which is not supported by experiments. during this study, we examined how a set of empirical relationships with measurable par ... | 2015 | 26433705 |
| contrasting strategies of alfalfa stem elongation in response to fall dormancy in early growth stage: the tradeoff between internode length and internode number. | fall dormancy (fd) in alfalfa (medicago sativa l.) can be described using 11 fd ratings, is widely used as an important indicator of stress resistance, productive performance and spring growth. however, the contrasting growth strategies in internode length and internode number in alfalfa cultivars with different fd rating are poorly understood. here, a growth chamber study was conducted to investigate the effect of fd on plant height, aboveground biomass, internode length, and internode number i ... | 2015 | 26281014 |
| leaf δ(15)n as a physiological indicator of the responsiveness of n2-fixing alfalfa plants to elevated [co2], temperature and low water availability. | the natural (15)n/(14)n isotope composition (δ(15)n) of a tissue is a consequence of its n source and n physiological mechanisms in response to the environment. it could potentially be used as a tracer of n metabolism in plants under changing environmental conditions, where primary n metabolism may be complex, and losses and gains of n fluctuate over time. in order to test the utility of δ(15)n as an indicator of plant n status in n2-fixing plants grown under various environmental conditions, al ... | 2015 | 26322051 |
| the medicago sativa gene index 1.2: a web-accessible gene expression atlas for investigating expression differences between medicago sativa subspecies. | alfalfa (medicago sativa l.) is the primary forage legume crop species in the united states and plays essential economic and ecological roles in agricultural systems across the country. modern alfalfa is the result of hybridization between tetraploid m. sativa ssp. sativa and m. sativa ssp. falcata. due to its large and complex genome, there are few genomic resources available for alfalfa improvement. | 2015 | 26149169 |
| characterization of the plant growth promoting bacterium, enterobacter cloacae msr1, isolated from roots of non-nodulating medicago sativa. | the aim of the present study was to characterize the endophytic bacterial strain designated msr1 that was isolated from inside the non-nodulating roots of medicago sativa after surface-sterilization. msr1 was identified as enterobacter cloacae using both 16s rdna gene sequence analysis and api20e biochemical identification system (biomerieux, france). furthermore, this bacterium was characterized using api50ch kit (biomerieux, france) and tested for antibacterial activities against some food bor ... | 2015 | 26858542 |
| biochemical and molecular phylogenetic study of agriculturally useful association of a nitrogen-fixing cyanobacterium and nodule sinorhizobium with medicago sativa l. | seed inoculation with bacterial consortium was found to increase legume yield, providing a higher growth than the standard nitrogen treatment methods. alfalfa plants were inoculated by mono- and binary compositions of nitrogen-fixing microorganisms. their physiological and biochemical properties were estimated. inoculation by microbial consortium of sinorhizobium meliloti t17 together with a new cyanobacterial isolate nostoc ptv was more efficient than the single-rhizobium strain inoculation. th ... | 2015 | 26114100 |
| the early events underlying genome evolution in a localized sinorhizobium meliloti population. | population genetic analyses based on genome-wide sequencing data have been carried out for sinorhizobium medicae and s. meliloti, two closely related bacterial species forming nitrogen-fixing symbioses with plants of the genus medicago. however, genome coverage was low or the isolates had a broad geographic distribution, making it difficult to interpret the estimated diversity and to unravel the early events underlying population genetic variations and ecological differentiation. | 2016 | 27495742 |
| loss of malic enzymes leads to metabolic imbalance and altered levels of trehalose and putrescine in the bacterium sinorhizobium meliloti. | malic enzymes decarboxylate the tricarboxylic acid (tca) cycle intermediate malate to the glycolytic end-product pyruvate and are well positioned to regulate metabolic flux in central carbon metabolism. despite the wide distribution of these enzymes, their biological roles are unclear in part because the reaction catalyzed by these enzymes can be by-passed by other pathways. the n2-fixing alfalfa symbiont sinorhizobium meliloti contains both a nad(p)-malic enzyme (dme) and a separate nadp-malic ... | 2016 | 27456220 |
| mixed nodule infection in sinorhizobium meliloti-medicago sativa symbiosis suggest the presence of cheating behavior. | in the symbiosis between rhizobia and legumes, host plants can form symbiotic root nodules with multiple rhizobial strains, potentially showing different symbiotic performances in nitrogen fixation. here, we investigated the presence of mixed nodules, containing rhizobia with different degrees of mutualisms, and evaluate their relative fitness in the sinorhizobium meliloti-medicago sativa model symbiosis. we used three s. meliloti strains, the mutualist strains rm1021 and bl225c and the non-mutu ... | 2016 | 27379128 |
| 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 ... | 2016 | 27203723 |
| assessing quality of medicago sativa silage by monitoring bacterial composition with single molecule, real-time sequencing technology and various physiological parameters. | the present study applied the pacbio single molecule, real-time sequencing technology (smrt) in evaluating the quality of silage production. specifically, we produced four types of medicago sativa silages by using four different lactic acid bacteria-based additives (ad-i, ad-ii, ad-iii and ad-iv). we monitored the changes in ph, organic acids (including butyric acid, the ratio of acetic acid/lactic acid, γ-aminobutyric acid, 4-hyroxy benzoic acid and phenyl lactic acid), mycotoxins, and bacteria ... | 2016 | 27340760 |
| enhancement of growth performance in pre-weaning suckling boer kids supplemented with creep feed containing alfalfa. | this study examined the effects of creep feed (cf) supplementation (with or without alfalfa) on the pre-weaning growth performance of nursing goat kids. | 2015 | 27065636 |
| a newly emerged cutaneous leishmaniasis focus in northern israel and two new reservoir hosts of leishmania major. | in 2006/7, 18 cases of cutaneous leishmaniasis (cl) were reported for the first time from sde eliyahu (pop. 650), a village in the beit she'an valley of israel. between 2007-2011, a further 88 cl cases were diagnosed bringing the total to 106 (16.3% of the population of sde eliyahu). the majority of cases resided in the south-western part of the village along the perimeter fence. the causative parasite was identified as leishmania major yakimoff & schokhor, 1914 (kinetoplastida: trypanosomatidae ... | 2013 | 23437408 |
| a plant-produced pfs25 vlp malaria vaccine candidate induces persistent transmission blocking antibodies against plasmodium falciparum in immunized mice. | malaria transmission blocking vaccines (tbvs) are considered an effective means to control and eventually eliminate malaria. the pfs25 protein, expressed predominantly on the surface of the sexual and sporogonic stages of plasmodium falciparum including gametes, zygotes and ookinetes, is one of the primary targets for tbv. it has been demonstrated that plants are an effective, highly scalable system for the production of recombinant proteins, including virus-like particles (vlps). we engineered ... | 2013 | 24260245 |
| insight into the salivary gland transcriptome of lygus lineolaris (palisot de beauvois). | the tarnished plant bug (tpb), lygus lineolaris (palisot de beauvois) is a polyphagous, phytophagous insect that has emerged as a major pest of cotton, alfalfa, fruits, and vegetable crops in the eastern united states and canada. using its piercing-sucking mouthparts, tpb employs a "lacerate and flush" feeding strategy in which saliva injected into plant tissue degrades cell wall components and lyses cells whose contents are subsequently imbibed by the tpb. it is known that a major component of ... | 2016 | 26789269 |
| morphological and molecular characterization of pratylenchus lentis n. sp. (nematoda: pratylenchidae) from sicily. | pratylenchus lentis n. sp. parasitizing roots of lentil in sicily, italy, is described and illustrated. the new species is characterized by a relatively high lip region with three annuli, mean stylet length of 16 mum, with anteriorly flattened knobs, cylindrical body with a relatively anterior vulva, large and ovoid spermatheca full of sperm, plump tail with truncate, irregularly annulated terminus, and by the presence of males. molecular its-rflp and sequencing analyses of the new species showe ... | 0 | 19440258 |
| sequencing and de novo assembly of the western tarnished plant bug (lygus hesperus) transcriptome. | mirid plant bugs (hemiptera: miridae) are economically important insect pests of many crops worldwide. the western tarnished plant bug lygus hesperus knight is a pest of cotton, alfalfa, fruit and vegetable crops, and potentially of several emerging biofuel and natural product feedstocks in the western us. however, little is known about the underlying molecular genetics, biochemistry, or physiology of l. hesperus, including their ability to survive extreme environmental conditions. | 2013 | 23357950 |
| plant growth regulatory effect and insecticidal activity of the extracts of the tree of heaven (ailanthus altissima l.). | there is an urgent need to explore and utilize naturally occurring products for combating harmful agricultural and public health pests. secondary metabolites in the leaves of the tree of heaven, ailanthus altissima l. have been reported to be herbicidal and insecticidal. the mode of action, however, of the active compounds in a. altissima are not understood. in this paper, we report the chemical characteristics of the herbicidal and insecticidal components in this tree, and will discuss the effe ... | 2002 | 11860616 |
| the mouthparts enriched odorant binding protein 11 of the alfalfa plant bug adelphocoris lineolatus displays a preferential binding behavior to host plant secondary metabolites. | odorant binding proteins (obps) are proposed to be directly required for odorant discrimination and represent potential interesting targets for pest control. in the notoriously agricultural pest adelphocoris lineolatus, our previous functional investigation of highly expressed antennal obps clearly supported this viewpoint, whereas the findings of the current study by characterizing of alinobp11 rather indicated that obp in hemipterous plant bugs might fulfill a different and tantalizing physiol ... | 2016 | 27313540 |
| similar patterns of linkage disequilibrium and nucleotide diversity in native and introduced populations of the pea aphid, acyrthosiphon pisum. | the pea aphid, acyrthosiphon pisum, is an emerging genomic model system for studies of polyphenisms, bacterial symbioses, host-plant specialization, and the vectoring of plant viruses. here we provide estimates of nucleotide diversity and linkage disequilibrium (ld) in native (european) and introduced (united states) populations of the pea aphid. because introductions can cause population bottlenecks, we hypothesized that u.s. populations harbor lower levels of nucleotide diversity and higher le ... | 2009 | 19470181 |
| methane emission by camelids. | methane emissions from ruminant livestock have been intensively studied in order to reduce contribution to the greenhouse effect. ruminants were found to produce more enteric methane than other mammalian herbivores. as camelids share some features of their digestive anatomy and physiology with ruminants, it has been proposed that they produce similar amounts of methane per unit of body mass. this is of special relevance for countrywide greenhouse gas budgets of countries that harbor large popula ... | 2014 | 24718604 |
| agrobacterium rhizogenes rol genes induce productivity-related phenotypical modifications in "creeping-rooted" alfalfa types. | agrobacterium rhizogenes rol genes were transferred individually or in combination into the forage legume medicago sativa l. (alfalfa). kanamycin resistant, neomycin phosphotransferase ii positive plants showed the presence of the rol inserts in their genome. phenotypical evaluation of transgenic populations indicated significant morphological alterations of the root system, stem number per plant and plant structure. a possible utilization of these transgenics in breeding programs of the so-call ... | 1995 | 24185517 |
| transformation of medicago arborea l. with an agrobacterium rhizogenes binary vector carrying the hygromycin resistance gene. | plants of medicago arborea have been infected with agrobacterium rhizogenes strain lba9402 harbouring the plasmids ri 1855 and ags125 carrying a gene conferring resistance to the antibiotic hygromycin. about 7056 of the hairy roots showed callus formation on hygromycin-supplemented medium. regeneration took place on antibiotic free medium only. plantlets suitable for transfer to soil were obtained after the manual removal of most of the leaves. plant morphology showed the usual alterations induc ... | 1991 | 24221661 |
| ri-plasmid as a helper for introducing vector dna into alfalfa plants. | genetic engineering of legumes and other important dicotyledonous plants is limited because of the difficulty of regenerating plants via cell culture. since a considerable number of crop plants can be regenerated only from root culture, the introduction of foreign genes into agrobacterium rhizogenes-induced hairy roots may expand the list of crop plants that could be genetically engineered. here we report genetic transformation of alfalfa (medicago sativa l.), a valuable forage legume, using a v ... | 1987 | 24301125 |
| hairy root transformation in alfalfa (medicago sativa l.). | the widely cultivated forage legume alfalfa (medicago sativa l.) was transformed with the agropine type agrobacterium rhizogenes ncppb 1855. sterile root and callus cultures were derived from tumorous hairy roots which were easily obtained independent of the plant variety or genotype. plant regeneration, via somatic embryogenesis, was achieved only when a selected alfalfa line, characterized by high regenerative capability, was utilized. genetic transformation was confirmed by the presence of ag ... | 1987 | 24241108 |
| a disarmed binary vector from agrobacterium tumefaciens functions in agrobacterium rhizogenes : frequent co-transformation of two distinct t-dnas. | binary ti plasmid vector systems consist of two plasmids in agrobacterium, where one plasmid contains the dna that can be transferred to plant cells and the other contains the virulence (vir) genes which are necessary for the dna transfer but are not themselves stably transferred. we have constructed two nononcogenic vectors (parc4 and parc8) based on the binary ti plasmid system of agrobacterium tumefaciens for plant transformation. each vector contains the left and right termini sequences from ... | 1986 | 24307418 |
| improvement of in vitro embryo maturation, plantlet regeneration and transformation efficiency from alfalfa (medicago sativa l.) somatic embryos using cuscuta campestris extract. | developmental deficiency of somatic embryos and regeneration to plantlets, especially in the case of transformation, are major problems of somatic embryo regeneration in alfalfa. one of the ways to overcome these problems is the use of natural plant regulators and nutrients in the culture medium of somatic embryos. for investigating the influence of cuscuta campestris extract on the efficiency of plant regeneration and transformation, chimeric tissue type plasminogen activator was transferred to ... | 2016 | 27729718 |
| overexpressing arabidopsis abf3 increases tolerance to multiple abiotic stresses and reduces leaf size in alfalfa. | arabidopsis abscisic acid-responsive element-binding factor 3 (abf3), a bzip transcription factor, plays an important role in regulating multiple stress responses in plants. overexpressing atabf3 increases tolerance to various stresses in several plant species. alfalfa (medicago sativa l.), one of the most important perennial forage crops worldwide, has high yields, high nutritional value, and good palatability and is widely distributed in irrigated and semi-arid regions throughout the world. ho ... | 2016 | 27721135 |
| co-expression of tonoplast cation/h(+) antiporter and h(+)-pyrophosphatase from xerophyte zygophyllum xanthoxylum improves alfalfa plant growth under salinity, drought and field conditions. | salinity and drought are major environmental factors limiting the growth and productivity of alfalfa worldwide as this economically important legume forage is sensitive to these kinds of abiotic stress. in this study, transgenic alfalfa lines expressing both tonoplast nxh and h(+)-ppase genes, zxnhx and zxvp1-1 from the xerophyte zygophyllum xanthoxylum l., were produced via agrobacterium tumefaciens-mediated transformation. compared with wild-type (wt) plants, transgenic alfalfa plants co-expre ... | 2016 | 26268400 |
| transgenic alfalfa plants expressing the sweetpotato orange gene exhibit enhanced abiotic stress tolerance. | alfalfa (medicago sativa l.), a perennial forage crop with high nutritional content, is widely distributed in various environments worldwide. we recently demonstrated that the sweetpotato orange gene (ibor) is involved in increasing carotenoid accumulation and enhancing resistance to multiple abiotic stresses. in this study, in an effort to improve the nutritional quality and environmental stress tolerance of alfalfa, we transferred the ibor gene into alfalfa (cv. xinjiang daye) under the contro ... | 2015 | 25946429 |
| viral and chloroplastic signals essential for initiation and efficiency of translation in agrobacterium tumefaciens. | the construction of high-level protein expression vectors using the camv 35s promoter in concert with highly efficient translation initiation signals for agrobacterium tumefaciens is a relatively less explored field compared to that of escherichia coli. in the current study, we experimentally investigated the capacity of the camv 35s promoter to direct gfp gene expression in a. tumefaciens in the context of different viral and chloroplastic translation initiation signals. gfp expression and conc ... | 2014 | 25117444 |
| expression of a fungal ferulic acid esterase in alfalfa modifies cell wall digestibility. | alfalfa (medicago sativa) is an important forage crop in north america owing to its high biomass production, perennial nature and ability to fix nitrogen. feruloyl esterase (ec 3.1.1.73) hydrolyzes ester linkages in plant cell walls and has the potential to further improve alfalfa as biomass for biofuel production. | 2014 | 24650274 |
| genetic transformation and analysis of rice osapx2 gene in medicago sativa. | the osapx2 gene from rice was cloned to produce pbi121::osapx2 dual-expression plants, of which expression level would be increasing under stressful conditions. the enzyme ascorbate peroxidase (apx) in the leaves and roots of the plants increased with increasing exposure time to different sodium chloride (nacl) and hydrogen peroxide (h(2)o(2))concentrations, as indicated by protein gel blot analysis. the increased enzyme yield improved the ability of the plants to resist the stress treatments. t ... | 2012 | 22848448 |
| transgenic expression of mshsp23 confers enhanced tolerance to abiotic stresses in tall fescue. | tall fescue (festuca arundinacea schreb.) is an important cool season forage plant that is not well suited to extreme heat, salts, or heavy metals. to develop transgenic tall fescue plants with enhanced tolerance to abiotic stress, we introduced an alfalfa hsp23 gene expression vector construct through agrobacterium-mediated transformation. integration and expression of the transgene were confirmed by polymerase chain reaction, northern blot, and western blot analyses. under normal growth condit ... | 2012 | 25049632 |
| introduction and expression of an insect proteinase inhibitor in alfalfa medicago sativa l. | as one approach to alleviating the need for insecticide spraying, our objective is to express protein insecticides in transgenic alfalfa. to initiate these studies, a cdna encoding the protease inhibitor (pi) anti-elastase from manduca sexta was placed under the control of the camv 35s promoter, inserted into pan 70, and transferred into leaf and petiole sections of alfalfa (medicago sativa l.) using agrobacterium tumefaciens mediated gene transfer. transformation rates were 10% of all explants ... | 1994 | 24194223 |