| a new class of regulatory genes underlying the cause of pear-shaped tomato fruit. | a common, recurring theme in domesticated plants is the occurrence of pear-shaped fruit. a major quantitative trait locus (termed ovate) controlling the transition from round to pear-shaped fruit has been cloned from tomato. ovate is expressed early in flower and fruit development and encodes a previously uncharacterized, hydrophilic protein with a putative bipartite nuclear localization signal, von willebrand factor type c domains, and an approximately equal 70-aa c-terminal domain conserved in ... | 2002 | 12242331 |
| interaction between domains of a plant nbs-lrr protein in disease resistance-related cell death. | many plant disease resistance (r) genes encode proteins predicted to have an n-terminal coiled-coil (cc) domain, a central nucleotide-binding site (nbs) domain and a c-terminal leucine-rich repeat (lrr) domain. these cc-nbs-lrr proteins recognize specific pathogen-derived products and initiate a resistance response that often includes a type of cell death known as the hypersensitive response (hr). co-expression of the potato cc-nbs-lrr protein rx and its elicitor, the pvx coat protein (cp), resu ... | 2002 | 12198153 |
| shoot meristem maintenance is controlled by a gras-gene mediated signal from differentiating cells. | plant shoot development depends on the perpetuation of a group of undifferentiated cells in the shoot apical meristem (sam). in the petunia mutant hairy meristem (ham), shoot meristems differentiate postembryonically as continuations of the subtending stem. ham encodes a putative transcription factor of the gras family, which acts non-cell-autonomously from l3-derived tissue of lateral organ primordia and stem provasculature. ham acts in parallel with terminator (phwuschel) and is required for c ... | 2002 | 12208843 |
| resistance of cultivated tomato to cell content-feeding herbivores is regulated by the octadecanoid-signaling pathway. | the octadecanoid signaling pathway has been shown to play an important role in plant defense against various chewing insects and some pathogenic fungi. here, we examined the interaction of a cell-content feeding arachnid herbivore, the two-spotted spider mite (tetranychus urticae koch), with cultivated tomato (lycopersicon esculentum) and an isogenic mutant line (defenseless-1 [def-1]) that is deficient in the biosynthesis of the octadecanoid pathway-derived signal, jasmonic acid (ja). spider mi ... | 2002 | 12226528 |
| characterization of a strong dominant phytochrome a mutation unique to phytochrome a signal propagation. | here, we report the isolation and characterization of a strong dominant-negative phytochrome a (phya) mutation (phya-300d) in arabidopsis. this mutation carries a single amino acid substitution at residue 631, from valine to methionine (v631m), in the core region within the c-terminal half of phya. this phya core region contains two protein-interactive motifs, pas1 and pas2. val-631 is located within the pas1 motif. the phya-v631m mutant protein is photochemically active and accumulates to a lev ... | 2002 | 12226524 |
| regulated expression of arabidopsis phosphate transporters. | phosphorus deficiency is one of the major abiotic stresses affecting plant growth. plants respond to the persistent deficiency of phosphate (pi) by coordinating the expression of genes involved in alleviation of the stress. the high-affinity pi transporters are among the major molecular determinants that are activated during pi stress. in this study, using three reporter genes (green fluorescent protein, luciferase, and beta-glucuronidase) regulated by two pi transporter promoters, we have carri ... | 2002 | 12226502 |
| effect of regulated overexpression of the mads domain factor agl15 on flower senescence and fruit maturation. | we have examined the effect of regulated overexpression of agl15, a member of the mads domain family of regulatory factors, on reproductive tissues. using molecular and physiological markers, we show that constitutive overexpression of agl15 in arabidopsis leads to delay and down-regulation of senescence programs in perianth organs and developing fruits and alters the process of seed desiccation. through genetic crosses, we show that the rate of water loss in the maturing seeds is dictated by th ... | 2002 | 12226488 |
| molecular dissection of the gibberellin/abscisic acid signaling pathways by transiently expressed rna interference in barley aleurone cells. | the interaction between two phytohormones, gibberellins (ga) and abscisic acid (aba), is an important factor regulating the developmental transition from seed dormancy to germination. in cereal aleurone tissue, ga induces and aba suppresses the expression of alpha-amylases that are essential for the utilization of starch stored in the endosperm. in this work, the signaling pathways mediated by these hormones were investigated in the aleurone cells of barley seeds using double-stranded rna interf ... | 2002 | 12215521 |
| disruption of a dna topoisomerase i gene affects morphogenesis in arabidopsis. | the genesis of phyllotaxis, which often is associated with the fibonacci series of numbers, is an old unsolved puzzle in plant morphogenesis. here, we show that disruption of an arabidopsis topoisomerase (topo) i gene named top1alpha affects phyllotaxis and plant architecture. the divergence angles and internode lengths between two successive flowers were more random in the top1alpha mutant than in the wild type. the top1alpha plants sporadically produced multiple flowers from one node, and the ... | 2002 | 12215507 |
| silencing of phosphoethanolamine n-methyltransferase results in temperature-sensitive male sterility and salt hypersensitivity in arabidopsis. | s-adenosyl-l-methionine:phosphoethanolamine n-methyltransferase (peamt; ec 2.1.1.103) catalyzes the key step in choline (cho) biosynthesis, the n-methylation of phosphoethanolamine. cho is a vital precursor of the membrane phospholipid phosphatidylcholine, which accounts for 40 to 60% of lipids in nonplastid plant membranes. certain plants use cho to produce the osmoprotectant glycine betaine, which confers resistance to salinity, drought, and other stresses. an arabidopsis mutant, t365, in whic ... | 2002 | 12215503 |
| high molecular weight rnas and small interfering rnas induce systemic posttranscriptional gene silencing in plants. | posttranscriptional gene silencing (ptgs) in transgenic plants is an epigenetic form of rna degradation related to ptgs and rna interference (rnai) in fungi and animals. evidence suggests that transgene loci and rna viruses can generate double-stranded rnas similar in sequence to the transcribed region of target genes, which then undergo endonucleolytic cleavage to generate small interfering rnas (sirna) that promote degradation of cognate rnas. the silent state in transgenic plants and in caeno ... | 2002 | 12181491 |
| down-regulation of tomato beta-galactosidase 4 results in decreased fruit softening. | transcript abundance of the gene encoding beta-galactosidase ii, a beta-galactosidase/exo-galactanase (ec 3.2.1.23) present during tomato (lycopersicon esculentum) fruit ripening, was suppressed by expression of an antisense tomato beta-galactosidase 4 (tbg4) cdna driven by the cauliflower mosaic virus 35s promoter. rna gel-blot analysis was used to evaluate tbg4 mrna levels in transgenic fruit. all of the antisense lines had attenuated tbg4 mrna levels in turning stage fruit; however, tbg4 mrna ... | 2002 | 12177488 |
| high-stearic and high-oleic cottonseed oils produced by hairpin rna-mediated post-transcriptional gene silencing. | we have genetically modified the fatty acid composition of cottonseed oil using the recently developed technique of hairpin rna-mediated gene silencing to down-regulate the seed expression of two key fatty acid desaturase genes, ghsad-1-encoding stearoyl-acyl-carrier protein delta 9-desaturase and ghfad2-1-encoding oleoyl-phosphatidylcholine omega 6-desaturase. hairpin rna-encoding gene constructs (hp) targeted against either ghsad-1 or ghfad2-1 were transformed into cotton (gossypium hirsutum c ... | 2002 | 12177486 |
| hprna-mediated targeting of the arabidopsis fad2 gene gives highly efficient and stable silencing. | the endogenous delta 12-desaturase gene (fad2) in arabidopsis was targeted for silencing using seed-specific cosuppression (cs), hairpin (hp) rna (hprna), and intron-spliced hp (ihp) constructs. the ihp construct, incorporating the 120-bp 3'-untranslated region of the fad2 gene, gave the highest degree of silencing. in some ihp lines delta 12-desaturase activity was reduced to levels as low as those in the null fad2-1 mutant, and every primary transformant showed a pronounced reduction in fad2 a ... | 2002 | 12177485 |
| a new resource of locally transposed dissociation elements for screening gene-knockout lines in silico on the arabidopsis genome. | we transposed dissociation (ds) elements from three start loci on chromosome 5 in arabidopsis (nossen ecotype) by using a local transposition system. we determined partial genomic sequences flanking the ds elements and mapped the elements' insertion sites in 1,173 transposed lines by comparison with the published genomic sequence. most of the lines contained a single copy of the ds element. one-half of the lines contained ds on chromosome 5; in particular, insertion "hot spots" near the three st ... | 2002 | 12177482 |
| activation tagging using the en-i maize transposon system in arabidopsis. | a method for the generation of stable activation tag inserts was developed in arabidopsis using the maize (zea mays) en-i transposon system. the method employs greenhouse selectable marker genes that are useful to efficiently generate large populations of insertions. a population of about 8,300 independent stable activation tag inserts has been produced. greenhouse-based screens for mutants in a group of plants containing about 2,900 insertions revealed about 31 dominant mutants, suggesting a do ... | 2002 | 12177467 |
| expression analysis of a family of nsltp genes tissue specifically expressed throughout the plant and during potato tuber life cycle. | non-specific lipid-transfer proteins (nsltps) are capable of binding lipid compounds in plant tissues and are coded by the nsltp genes. here, we present the analysis of expression of a family of potato (solanum tuberosum) nsltp genes that express throughout the developing plant in a highly tissue-specific manner. three transcript-derived fragments were isolated using an amplified restriction fragment polymorphism-derived technique for rna fingerprinting that show homology to plant nsltp genes. t ... | 2002 | 12177463 |
| actin2 is essential for bulge site selection and tip growth during root hair development of arabidopsis. | root hairs develop as long extensions from root epidermal cells. after the formation of an initial bulge at the distal end of the epidermal cell, the root hair structure elongates by tip growth. because root hairs are not surrounded by other cells, root hair formation provides an excellent system for studying the highly complex process of plant cell growth. pharmacological experiments with actin filament-interfering drugs have provided evidence that the actin cytoskeleton is an important factor ... | 2002 | 12177460 |
| the scf(coi1) ubiquitin-ligase complexes are required for jasmonate response in arabidopsis. | xie and colleagues previously isolated the arabidopsis coi1 gene that is required for response to jasmonates (jas), which regulate root growth, pollen fertility, wound healing, and defense against insects and pathogens. in this study, we demonstrate that coi1 associates physically with atcul1, atrbx1, and either of the arabidopsis skp1-like proteins ask1 or ask2 to assemble ubiquitin-ligase complexes, which we have designated scf(coi1). coi1(e22a), a single amino acid substitution in the f-box m ... | 2002 | 12172031 |
| ptabi3 impinges on the growth and differentiation of embryonic leaves during bud set in poplar. | the arabidopsis abscisic acid-insensitive3 (abi3) protein plays a crucial role during late seed development and has an additional function at the vegetative meristem, particularly during periods of growth-arresting conditions and quiescence. here, we show that the abi3 homolog of poplar (ptabi3) is expressed in buds during natural bud set. expression occurs clearly after perception of the critical daylength that initiates bud set and dormancy in poplar. in short-day conditions mimicking natural ... | 2002 | 12172029 |
| frd3, a member of the multidrug and toxin efflux family, controls iron deficiency responses in arabidopsis. | we present the cloning and characterization of an arabidopsis gene, frd3, involved in iron homeostasis. plants carrying any of the three alleles of frd3 constitutively express three strategy i iron deficiency responses and misexpress a number of iron deficiency-regulated genes. mutant plants also accumulate approximately twofold excess iron, fourfold excess manganese, and twofold excess zinc in their shoots. frd3-3 was first identified as man1. the frd3 gene is expressed at detectable levels in ... | 2002 | 12172022 |
| ectopic expression of baby boom triggers a conversion from vegetative to embryonic growth. | the molecular mechanisms underlying the initiation and maintenance of the embryonic pathway in plants are largely unknown. to obtain more insight into these processes, we used subtractive hybridization to identify genes that are upregulated during the in vitro induction of embryo development from immature pollen grains of brassica napus (microspore embryogenesis). one of the genes identified, baby boom (bbm), shows similarity to the ap2/erf family of transcription factors and is expressed prefer ... | 2002 | 12172019 |
| cellular and subcellular localization of phototropin 1. | phototropin 1 (phot1) is a ser/thr photoreceptor kinase that binds two molecules of flavin mononucleotide as its chromophores and undergoes autophosphorylation in response to blue light. phot1 is plasma membrane associated and, as with phot2, has been shown to function as a photoreceptor for phototropism, blue light-induced chloroplast movement, and blue light-induced stomatal opening. phot1 likely also plays a redundant role with phot2 in regulating the rate of leaf expansion. understanding the ... | 2002 | 12172018 |
| the polaris gene of arabidopsis encodes a predicted peptide required for correct root growth and leaf vascular patterning. | the polaris (pls) gene of arabidopsis was identified as a promoter trap transgenic line, showing beta-glucuronidase fusion gene expression predominantly in the embryonic and seedling root, with low expression in aerial parts. cloning of the pls locus revealed that the promoter trap t-dna had inserted into a short open reading frame (orf). rapid amplification of cdna ends pcr, rna gel blot analysis, and rnase protection assays showed that the pls orf is located within a short ( approximately 500 ... | 2002 | 12172017 |
| cold-regulated cereal chloroplast late embryogenesis abundant-like proteins. molecular characterization and functional analyses. | cold acclimation and freezing tolerance are the result of complex interaction between low temperature, light, and photosystem ii (psii) excitation pressure. previous results have shown that expression of the wcs19 gene is correlated with psii excitation pressure measured in vivo as the relative reduction state of psii. using cdna library screening and data mining, we have identified three different groups of proteins, late embryogenesis abundant (lea) 3-l1, lea3-l2, and lea3-l3, sharing identiti ... | 2002 | 12114590 |
| combinatorial interaction of cis elements specifies the expression of the arabidopsis athsp90-1 gene. | the promoter region of the arabidopsis athsp90-1 gene is congested with heat shock elements and stress response elements, as well as with other potential transcriptional binding sites (activating protein 1, ccaat/enhancer-binding protein element, and metal regulatory element). to determine how the expression of this bona fide athsp90-1 gene is regulated, a comprehensive quantitative and qualitative promoter deletion analysis was conducted under various environmental conditions and during develop ... | 2002 | 12114568 |
| distinct physiological roles of fructokinase isozymes revealed by gene-specific suppression of frk1 and frk2 expression in tomato. | there are two divergent fructokinase isozymes, frk1 and frk2 in tomato (lycopersicon esculentum mill.) plants. to investigate the physiological functions of each isozyme, the expression of each fructokinase mrna was independently suppressed in transgenic tomato plants, and the respective phenotypes were evaluated. suppression of frk1 expression resulted in delayed flowering at the first inflorescence. suppression of frk2 did not effect flowering time but resulted in growth inhibition of stems an ... | 2002 | 12114566 |
| heterology expression of the arabidopsis c-repeat/dehydration response element binding factor 1 gene confers elevated tolerance to chilling and oxidative stresses in transgenic tomato. | in an attempt to improve stress tolerance of tomato (lycopersicon esculentum) plants, an expression vector containing an arabidopsis c-repeat/dehydration responsive element binding factor 1 (cbf1) cdna driven by a cauliflower mosaic virus 35s promoter was transferred into tomato plants. transgenic expression of cbf1 was proved by northern- and western-blot analyses. the degree of chilling tolerance of transgenic t(1) and t(2) plants was found to be significantly greater than that of wild-type to ... | 2002 | 12114563 |
| hypersensitivity of abscisic acid-induced cytosolic calcium increases in the arabidopsis farnesyltransferase mutant era1-2. | cytosolic calcium increases were analyzed in guard cells of the arabidopsis farnesyltransferase deletion mutant era1-2 (enhanced response to abscisic acid). at low abscisic acid (aba) concentrations (0.1 microm), increases of guard cell cytosolic calcium and stomatal closure were activated to a greater extent in the era1-2 mutant compared with the wild type. patch clamping of era1-2 guard cells showed enhanced aba sensitivity of plasma membrane calcium channel currents. these data indicate that ... | 2002 | 12119381 |
| the arabidopsis sku5 gene encodes an extracellular glycosyl phosphatidylinositol-anchored glycoprotein involved in directional root growth. | to investigate how roots respond to directional cues, we characterized a t-dna-tagged arabidopsis mutant named sku5 in which the roots skewed and looped away from the normal downward direction of growth on inclined agar surfaces. sku5 roots and etiolated hypocotyls were slightly shorter than normal and exhibited a counterclockwise (left-handed) axial rotation bias. the surface-dependent skewing phenotype disappeared when the roots penetrated the agar surface, but the axial rotation defect persis ... | 2002 | 12119380 |
| endogenous and silencing-associated small rnas in plants. | a large set of endogenous small rnas of predominantly 21 to 24 nucleotides was identified in arabidopsis. these small rnas resembled micro-rnas from animals and were similar in size to small interfering rnas that accumulated during rna silencing triggered by multiple types of inducers. among the 125 sequences identified, the vast majority (90%) arose from intergenic regions, although small rnas corresponding to predicted protein-coding genes, transposon-like sequences, and a structural rna gene ... | 2002 | 12119378 |
| the arabidopsis mutant cev1 links cell wall signaling to jasmonate and ethylene responses. | biotic and abiotic stresses stimulate the synthesis of jasmonates and ethylene, which, in turn, induce the expression of genes involved in stress response and enhance defense responses. the cev1 mutant has constitutive expression of stress response genes and has enhanced resistance to fungal pathogens. here, we show that cev1 plants have increased production of jasmonate and ethylene and that its phenotype is suppressed by mutations that interrupt jasmonate and ethylene signaling. genetic mappin ... | 2002 | 12119374 |
| nucleocytoplasmic partitioning of the plant photoreceptors phytochrome a, b, c, d, and e is regulated differentially by light and exhibits a diurnal rhythm. | the phytochrome family of plant photoreceptors has a central role in the adaptation of plant development to changes in ambient light conditions. the individual phytochrome species regulate different or partly overlapping physiological responses. we generated transgenic arabidopsis plants expressing phytochrome a to e:green fluorescent protein (gfp) fusion proteins to assess the biological role of intracellular compartmentation of these photoreceptors in light-regulated signaling. we show that al ... | 2002 | 12119373 |
| homeodomain protein athb6 is a target of the protein phosphatase abi1 and regulates hormone responses in arabidopsis. | abi1, a protein phosphatase 2c, is a key component of signal transduction in arabidopsis. it regulates diverse responses to the phytohormone abscisic acid (aba) such as stomatal closure, seed dormancy and inhibition of vegetative growth. by analysing proteins capable of interacting with abi1, we have identified the homeodomain protein athb6 as a regulator of the aba signal pathway. critical for interaction between athb6 and abi1 is an intact protein phosphatase domain and the n-terminal domain o ... | 2002 | 12065416 |
| a viral protein suppresses rna silencing and binds silencing-generated, 21- to 25-nucleotide double-stranded rnas. | posttranscriptional gene silencing (ptgs) processes double-stranded (ds) rnas into 21-25 nucleotide (nt) rna fragments that direct ribonucleases to target cognate mrnas. in higher plants, ptgs also generates mobile signals conferring sequence-specific silencing in distant organs. since ptgs acts as an antiviral system in plants, successful virus infection requires evasion or suppression of gene silencing. here we report that the 19 kda protein (p19) of tombusviruses is a potent silencing suppres ... | 2002 | 12065420 |
| in the complex family of heat stress transcription factors, hsfa1 has a unique role as master regulator of thermotolerance in tomato. | we generated transgenic tomato plants with altered expression of heat stress transcription factor hsfa1. plants with 10-fold overexpression of hsfa1 (oe plants) were characterized by a single hsfa1 transgene cassette, whereas plants harboring a tandem inverted repeat of the cassette showed cosuppression (cs plants) by posttranscriptional silencing of the hsfa1 gene connected with formation of small interfering rnas. under normal growth conditions, major developmental parameters were similar for ... | 2002 | 12080093 |
| functional analysis of the cellulose synthase genes cesa1, cesa2, and cesa3 in arabidopsis. | polysaccharide analyses of mutants link several of the glycosyltransferases encoded by the 10 cesa genes of arabidopsis to cellulose synthesis. features of those mutant phenotypes point to particular genes depositing cellulose predominantly in either primary or secondary walls. we used transformation with antisense constructs to investigate the functions of cesa2 (atha) and cesa3 (athb), genes for which reduced synthesis mutants are not yet available. plants expressing antisense cesa1 (rsw1) pro ... | 2002 | 12068120 |
| the lateral organ boundaries gene defines a novel, plant-specific gene family. | the lateral organ boundaries (lob) gene in arabidopsis defines a new conserved protein domain. lob is expressed in a band of cells at the adaxial base of all lateral organs formed from the shoot apical meristem and at the base of lateral roots. lob encodes a predicted protein that does not have recognizable functional motifs, but that contains a conserved domain (the lob domain) that is present in 42 other arabidopsis proteins and in proteins from a variety of other plant species. proteins showi ... | 2002 | 12068116 |
| remodeling of dna methylation and phenotypic and transcriptional changes in synthetic arabidopsis allotetraploids. | the joining of different genomes in allotetraploids played a major role in plant evolution, but the molecular implications of this event are poorly understood. in synthetic allotetraploids of arabidopsis and cardaminopsis arenosa, we previously demonstrated the occurrence of frequent gene silencing. to explore the involvement of epigenetic phenomena, we investigated the occurrence and effects of dna methylation changes. changes in dna methylation patterns were more frequent in synthetic allotetr ... | 2002 | 12068115 |
| raspberry3 gene encodes a novel protein important for embryo development. | we identified a new gene that is interrupted by t-dna in an arabidopsis embryo mutant called raspberry3. raspberry3 has "raspberry-like" cellular protuberances with an enlarged suspensor characteristic of other raspberry embryo mutants, and is arrested morphologically at the globular stage of embryo development. the predicted raspberry3 protein has domains found in proteins present in prokaryotes and algae chloroplasts. computer prediction analysis suggests that the raspberry3protein may be loca ... | 2002 | 12068112 |
| regulation of the cell expansion gene rhd3 during arabidopsis development. | the rhd3 (root hair defective3) gene encodes a putative gtp-binding protein required for appropriate cell enlargement in arabidopsis. to obtain insight into the mechanisms of rhd3 regulation, we conducted a molecular genetic dissection of rhd3 gene expression and function. gene fusion and complementation studies show that the rhd3 gene is highly expressed throughout arabidopsis development and is controlled by two major regulatory regions. one regulatory region is located between -1,500 and -600 ... | 2002 | 12068108 |
| metabolic and environmental regulation of 3-methylcrotonyl-coenzyme a carboxylase expression in arabidopsis. | 3-methylcrotonyl-coenzyme a carboxylase (mccase) is a nuclear-encoded, mitochondrial biotin-containing enzyme composed of two types of subunits: the biotinylated mcc-a subunit (encoded by the gene at1g03090) and the non-biotinylated mcc-b subunit (encoded by the gene at4g34030). the major metabolic role of mccase is in the mitochondrial catabolism of leucine, and it also might function in the catabolism of isoprenoids and the mevalonate shunt. in the work presented herein, the single-copy gene e ... | 2002 | 12068107 |
| spindly is a nuclear-localized repressor of gibberellin signal transduction expressed throughout the plant. | spy (spindly) encodes a putative o-linked n-acetyl-glucosamine transferase that is genetically defined as a negatively acting component of the gibberellin (ga) signal transduction pathway. analysis of arabidopsis plants containing a spy::gus reporter gene reveals that spy is expressed throughout the life of the plant and in most plant organs examined. in addition to being expressed in all organs where phenotypes due to spy mutations have been reported, spy::gus is expressed in the root. examinat ... | 2002 | 12068105 |
| regulation of clv3 expression by two homeobox genes in arabidopsis. | the ability of meristems to continuously produce new organs depends on the activity of their stem cell populations, which are located at the meristem tip. in arabidopsis, the size of the stem cell domain is regulated by two antagonistic activities. the wus (wuschel) gene, encoding a homeodomain protein, promotes the formation and maintenance of stem cells. these stem cells express clv3 (clavata3), and signaling of clv3 through the clv1/clv2 receptor complex restricts wus activity. homeostasis of ... | 2002 | 12068101 |
| the plastidic 2-cysteine peroxiredoxin is a target for a thioredoxin involved in the protection of the photosynthetic apparatus against oxidative damage. | the chloroplastic drought-induced stress protein of 32 kd (cdsp32) is composed of two thioredoxin modules and is induced by environmental and oxidative stress conditions. we investigated whether the plastidic protein bas1, which is related to eubacterial 2-cys peroxiredoxin, is a target for cdsp32. using a cdsp32 active-site mutant, we showed that the bas1 and cdsp32 proteins form a mixed disulfide complex in vitro. moreover, affinity chromatography indicated that bas1 is a major target for cdsp ... | 2002 | 12084836 |
| transparent testa glabra2, a trichome and seed coat development gene of arabidopsis, encodes a wrky transcription factor. | mutants of a new gene, transparent testa glabra2 (ttg2), show disruptions to trichome development and to tannin and mucilage production in the seed coat. the gene was tagged by the endogenous transposon tag1 and shown to encode a wrky transcription factor. it is the first member of this large, plant-specific family known to control morphogenesis. the functions of all other wrky genes revealed to date involve responses to pathogen attack, mechanical stress, and senescence. ttg2 is strongly expres ... | 2002 | 12084832 |
| expression of the irt1 metal transporter is controlled by metals at the levels of transcript and protein accumulation. | iron, an essential nutrient, is not readily available to plants because of its low solubility. in addition, iron is toxic in excess, catalyzing the formation of hydroxyl radicals that can damage cellular constituents. consequently, plants must carefully regulate iron uptake so that iron homeostasis is maintained. the arabidopsis irt1 gene is the major transporter responsible for high-affinity iron uptake from the soil. here, we show that the steady state level of irt1 mrna was induced within 24 ... | 2002 | 12084831 |
| a mitochondrial complex i defect impairs cold-regulated nuclear gene expression. | to study low-temperature signaling in plants, we previously screened for cold stress response mutants using bioluminescent arabidopsis plants that express the firefly luciferase reporter gene driven by the stress-responsive rd29a promoter. here, we report on the characterization and cloning of one mutant, frostbite1 (fro1), which shows reduced luminescence induction by cold. fro1 plants display reduced cold induction of stress-responsive genes such as rd29a, kin1, cor15a, and cor47. fro1 leaves ... | 2002 | 12084824 |
| irt1, an arabidopsis transporter essential for iron uptake from the soil and for plant growth. | plants are the principal source of iron in most diets, yet iron availability often limits plant growth. in response to iron deficiency, arabidopsis roots induce the expression of the divalent cation transporter irt1. here, we present genetic evidence that irt1 is essential for the uptake of iron from the soil. an arabidopsis knockout mutant in irt1 is chlorotic and has a severe growth defect in soil, leading to death. this defect is rescued by the exogenous application of iron. the mutant plants ... | 2002 | 12084823 |
| somatic embryogenesis in elm. | we show that isolated zygotic embryos of ulmus minor and u. glabra can produce embryogenic cultures provided they are isolated from immature seeds before storage proteins begin to accumulate. rates of somatic embryogenesis were highest among zygotic embryos collected 6 weeks post-anthesis when they were at the midcotyledonary stage, were about 5 mm long and had a fresh weight of approx. 10 mg. at this time, induction was even possible in murashige and skoog basal medium with no plant growth regu ... | 2002 | 12099539 |
| laccase down-regulation causes alterations in phenolic metabolism and cell wall structure in poplar. | laccases are encoded by multigene families in plants. previously, we reported the cloning and characterization of five divergent laccase genes from poplar (populus trichocarpa) xylem. to investigate the role of individual laccase genes in plant development, and more particularly in lignification, three independent populations of antisense poplar plants, lac3as, lac90as, and lac110as with significantly reduced levels of laccase expression were generated. a repression of laccase gene expression ha ... | 2002 | 12011346 |
| direct interference with rhamnogalacturonan i biosynthesis in golgi vesicles. | pectin is a class of complex cell wall polysaccharides with multiple roles during cell development. assigning specific functions to particular polysaccharides is in its infancy, in part, because of the limited number of mutants and transformants available with modified pectic polymers in their walls. pectins are also important polymers with diverse applications in the food and pharmaceutical industries, which would benefit from technology for producing pectins with specific functional properties ... | 2002 | 12011341 |
| the cell wall hydroxyproline-rich glycoprotein rsh is essential for normal embryo development in arabidopsis. | although a large number of embryo mutants have been studied, mostly at the morphological level, the critical molecular and cellular events responsible for embryogenesis are unknown. here, we report that using an enhancer-trap embryo mutant of arabidopsis, we identified a gene, root-shoot-hypocotyl-defective (rsh), that is essential for the correct positioning of the cell plate during cytokinesis in cells of the developing embryo. we traced the earliest point of influence of rsh to the first asym ... | 2002 | 12034904 |
| an arabidopsis mitogen-activated protein kinase kinase kinase gene family encodes essential positive regulators of cytokinesis. | the signal transduction pathways that control cytokinesis in plants are largely uncharacterized. here, we provide genetic evidence that mitogen-activated protein kinase kinase kinases (mapkkks) play a role in the control of plant cell division. using a reverse-genetic approach, we isolated plants carrying knockout alleles of the arabidopsis mapkkk genes anp1, anp2, and anp3. the resulting single-mutant plants displayed no obvious abnormal phenotypes; two of the three double-mutant combinations d ... | 2002 | 12034900 |
| hydra mutants of arabidopsis are defective in sterol profiles and auxin and ethylene signaling. | the hydra mutants of arabidopsis are characterized by a pleiotropic phenotype that shows defective embryonic and seedling cell patterning, morphogenesis, and root growth. we demonstrate that the hydra1 gene encodes a delta8-delta7 sterol isomerase, whereas hydra2 encodes a sterol c14 reductase, previously identified as the fackel gene product. seedlings mutant for each gene are similarly defective in the concentrations of the three major arabidopsis sterols. promoter::reporter gene analysis show ... | 2002 | 12034894 |
| the use of arabidopsis to study interactions between parasitic angiosperms and their plant hosts. | parasitic plants invade host plants in order to rob them of water, minerals and nutrients. the consequences to the infected hosts can be debilitating and some of the world's most pernicious agricultural weeds are parasitic. parasitic genera of the scrophulariaceae and orobanchaceae directly invade roots of neighboring plants via underground structures called haustoria. the mechanisms by which these parasites identify and associate with host plants present unsurpassed opportunities for studying c ... | 2002 | 22303205 |
| green fluorescent protein as a visual marker in somatic hybridization. | using a transgenic citrus plant expressing green fluorescent protein (gfp) as a parent in somatic fusion experiments, we investigated the suitability of gfp as an in vivo marker to follow the processes of protoplast fusion, regeneration and selection of hybrid plants. a high level of gfp expression was detected in transgenic citrus protoplasts, hybrid callus, embryos and plants. it is demonstrated that gfp can be used for the continuous monitoring of the fusion process, localization of hybrid co ... | 2002 | 12096810 |
| mutational analysis of the ethylene receptor etr1. role of the histidine kinase domain in dominant ethylene insensitivity. | the ethylene receptor family of arabidopsis consists of five members, one of these being etr1. the n-terminal half of etr1 contains a hydrophobic domain responsible for ethylene binding and membrane localization. the c-terminal half of the polypeptide contains domains with homology to histidine (his) kinases and response regulators, signaling motifs originally identified in bacteria. the role of the his kinase domain in ethylene signaling was examined in planta. for this purpose, site-directed m ... | 2002 | 11950991 |
| functional properties and regulatory complexity of a minimal rbcs light-responsive unit activated by phytochrome, cryptochrome, and plastid signals. | light-inducible promoters are able to respond to a wide spectrum of light through multiple photoreceptor systems. several cis-acting elements have been identified as components of light-responsive promoter elements; however, none of these regulatory elements by itself appears to be sufficient to confer light responsiveness; rather, the combination of at least two elements seems to be required. using phylogenetic structural analysis, we have identified conserved dna modular arrays (cmas) associat ... | 2002 | 11950971 |
| spreading of rna targeting and dna methylation in rna silencing requires transcription of the target gene and a putative rna-dependent rna polymerase. | rna silencing is a sequence-specific rna degradation process that follows the recognition of double-stranded rna. here, we show that virus vectors carrying parts of a green fluorescent protein (gfp) transgene targeted rna silencing in nicotiana benthamiana and arabidopsis against the entire gfp rna. these results indicate that there was spreading of rna targeting from the initiator region into the adjacent 5' and 3' regions of the target gene. spreading was accompanied by methylation of the corr ... | 2002 | 11971140 |
| the arabidopsis rop2 gtpase is a positive regulator of both root hair initiation and tip growth. | root hairs provide a model system for the study of cell polarity. we examined the possibility that one or more members of the distinct plant subfamily of rho monomeric gtpases, termed rop, may function as molecular switches regulating root hair growth. specific rops are known to control polar growth in pollen tubes. overexpressing rop2 (rop2 ox) resulted in a strong root hair phenotype, whereas overexpressing rop7 appeared to inhibit root hair tip growth. overexpressing rops from other phylogene ... | 2002 | 11971133 |
| the family-3 glycoside hydrolases: from housekeeping functions to host-microbe interactions. | | 2002 | 11916659 |
| cytokinins. | | 2002 | 22303214 |
| the homeobox gene brevipedicellus is a key regulator of inflorescence architecture in arabidopsis. | flowering plants display a remarkable range of inflorescence architecture, and pedicel characteristics are one of the key contributors to this diversity. however, very little is known about the genes or the pathways that regulate pedicel development. the brevipedicellus (bp) mutant of arabidopsis thaliana displays a unique phenotype with defects in pedicel development causing downward-pointing flowers and a compact inflorescence architecture. cloning and molecular analysis of two independent mut ... | 2002 | 11917137 |
| atkc1, a silent arabidopsis potassium channel alpha -subunit modulates root hair k+ influx. | ion channels in roots allow the plant to gain access to nutrients. the composition of the individual ion channels and the functional contribution of different alpha-subunits is largely unknown. focusing on k(+)-selective ion channels, we have characterized atkc1, a new alpha-subunit from the arabidopsis shaker-like ion channel family. promoter-beta-glucuronidase (gus) studies identified atkc1 expression predominantly in root hairs and root endodermis. specific antibodies recognized atkc1 at the ... | 2002 | 11904452 |
| floozy of petunia is a flavin mono-oxygenase-like protein required for the specification of leaf and flower architecture. | the mechanisms that determine the relative positions of floral organs, and thereby their numbers, is a poorly understood aspect of flower development. we isolated a petunia mutant, floozy (fzy), in which the formation of floral organ primordia in the outermost three floral whorls and one of the two bracts at the base of the flower is blocked at an early stage. in addition, fzy mutants fail to generate secondary veins in leaves and bracts and display a decreased apical dominance in the infloresce ... | 2002 | 11914280 |
| control of proliferation, endoreduplication and differentiation by the arabidopsis e2fa-dpa transcription factor. | new plant cells arise at the meristems, where they divide a few times before they leave the cell-cycle program and start to differentiate. here we show that the e2fa-dpa transcription factor of arabidopsis thaliana is a key regulator determining the proliferative status of plant cells. ectopic expression of e2fa induced sustained cell proliferation in normally differentiated cotyledon and hypocotyl cells. the phenotype was enhanced strongly by the co-expression of e2fa with its dimerization part ... | 2002 | 11889041 |
| leaf urea metabolism in potato. urease activity profile and patterns of recovery and distribution of (15)n after foliar urea application in wild-type and urease-antisense transgenics. | the influence of urease activity on n distribution and losses after foliar urea application was investigated using wild-type and transgenic potato (solanum tuberosum cv désirée) plants in which urease activity was down-regulated. a good correlation between urease activity and (15)n urea metabolism (nh(3) accumulation) was found. the general accumulation of ammonium in leaves treated with urea indicated that urease activity is not rate limiting, at least initially, for the assimilation of urea n ... | 2002 | 11891267 |
| simultaneous visualization of peroxisomes and cytoskeletal elements reveals actin and not microtubule-based peroxisome motility in plants. | peroxisomes were visualized in living plant cells using a yellow fluorescent protein tagged with a peroxisomal targeting signal consisting of the skl motif. simultaneous visualization of peroxisomes and microfilaments/microtubules was accomplished in onion (allium cepa) epidermal cells transiently expressing the yellow fluorescent protein-peroxi construct, a green fluorescent protein-mtalin construct that labels filamentous-actin filaments, and a green fluorescent protein-microtubule-binding dom ... | 2002 | 11891258 |
| delayed abscission and shorter internodes correlate with a reduction in the ethylene receptor leetr1 transcript in transgenic tomato. | stable transformation of tomato (lycopersicon esculentum cv ailsa craig) plants with a construct containing the antisense sequence for the receiver domain and 3'-untranslated portion of the tomato ethylene receptor (leetr1) under the control of an enhanced cauliflower mosaic virus 35s promoter resulted in some expected and unexpected phenotypes. in addition to reduced leetr1 transcript levels, the two most consistently observed phenotypes in the transgenic lines were delayed abscission and reduc ... | 2002 | 11891253 |
| adenosine kinase deficiency is associated with developmental abnormalities and reduced transmethylation. | adenosine (ado) kinase (adk; atp:ado 5' phosphotransferase, ec 2.7.1.20) catalyzes the salvage synthesis of adenine monophosphate from ado and atp. in arabidopsis, adk is encoded by two cdnas that share 89% nucleotide identity and are constitutively, yet differentially, expressed in leaves, stems, roots, and flowers. to investigate the role of adk in plant metabolism, lines deficient in this enzyme activity have been created by sense and antisense expression of the adk1 cdna. the levels of adk a ... | 2002 | 11891238 |
| in vivo analysis of the role of attic20 in protein import into chloroplasts. | the import of nucleus-encoded preproteins into plastids requires the coordinated activities of membrane protein complexes that facilitate the translocation of polypeptides across the envelope double membrane. tic20 was identified previously as a component of the import machinery of the inner envelope membrane by covalent cross-linking studies with trapped preprotein import intermediates. to investigate the role of tic20 in preprotein import, we altered the expression of the arabidopsis tic20 ort ... | 2002 | 11910011 |
| knat1 and erecta regulate inflorescence architecture in arabidopsis. | plant architecture is dictated by morphogenetic factors that specify the number and symmetry of lateral organs as well as their positions relative to the primary axis. mutants defective in the patterning of leaves and floral organs have provided new insights on the signaling pathways involved, but there is comparatively little information regarding aspects of the patterning of stems, which play a dominant role in architecture. to this end, we have characterized five alleles of the brevipedicellu ... | 2002 | 11910003 |
| complete inhibition of tobamovirus multiplication by simultaneous mutations in two homologous host genes. | the tom1 gene of arabidopsis thaliana encodes a putative multipass transmembrane protein which is necessary for the efficient multiplication of tobamoviruses. we have previously shown that mutations severely destructive to the tom1 gene reduce tobamovirus multiplication to low levels but do not impair it completely. in this report, we subjected one of the tom1 mutants (tom1-1) to another round of mutagenesis and isolated a new mutant which did not permit a detectable level of tobamovirus multipl ... | 2002 | 11836427 |
| shepherd is the arabidopsis grp94 responsible for the formation of functional clavata proteins. | the arabidopsis shepherd (shd) mutant shows expanded shoot apical meristems (sam) and floral meristems (fm), disorganized root apical meristems, and defects in pollen tube elongation. we have discovered that shd encodes an ortholog of grp94, an er-resident hsp90-like protein. since the shd phenotypes in sam and fm are similar to those of the clavata (clv) mutants, we have explored the possibility that clv complex members could be shd targets. the sam and fm morphology of shd clv double mutants a ... | 2002 | 11867518 |
| the mur2 mutant of arabidopsis thaliana lacks fucosylated xyloglucan because of a lesion in fucosyltransferase atfut1. | cell walls of the arabidopsis mutant mur2 contain less than 2% of the wild-type amount of fucosylated xyloglucan because of a point mutation in the fucosyltransferase atfut1. the mur2 mutation eliminates xyloglucan fucosylation in all major plant organs, indicating that arabidopsis thaliana fucosyltransferase 1 (atfut1) accounts for all of the xyloglucan fucosyltransferase activity in arabidopsis. despite this alteration in structure, mur2 plants show a normal growth habit and wall strength. in ... | 2002 | 11854459 |
| light modulation of rubisco in arabidopsis requires a capacity for redox regulation of the larger rubisco activase isoform. | the light activation of ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco) in vivo requires the presence of rubisco activase, a nuclear-encoded chloroplast protein that consists of two isoforms arising from alternative splicing in most plants. we examined the function of each isoform by characterizing rubisco activation in transgenic arabidopsis plants that express only one or both isoforms, as compared with the wild type. in plants expressing only the shorter isoform, rubisco activity wa ... | 2002 | 11854454 |
| constitutive expression of a single antimicrobial peptide can restore wild-type resistance to infection in immunodeficient drosophila mutants. | one of the characteristics of the host defense of insects is the rapid synthesis of a variety of potent antibacterial and antifungal peptides. to date, seven types of inducible antimicrobial peptides (amps) have been characterized in drosophila. the importance of these peptides in host defense is supported by the observation that flies deficient for the toll or immune deficiency (imd) pathway, which affects amp gene expression, are extremely susceptible to microbial infection. here we have devel ... | 2002 | 11854512 |
| pollen tube development and competitive ability are impaired by disruption of a shaker k(+) channel in arabidopsis. | sexual reproduction in plants requires elongation of the pollen tube through the transmitting tissues toward the ovary. tube growth rate is a major determinant of pollen competitive ability. we report that a k(+) channel of the shaker family in arabidopsis, spik, plays an important role in pollen tube development. spik was found to be specifically expressed in pollen. when spik was heterologously expressed in cos cells, its product formed hyperpolarization-activated k(+) channels. disruption (t- ... | 2002 | 11825875 |
| axr1-ecr1-dependent conjugation of rub1 to the arabidopsis cullin atcul1 is required for auxin response. | mutations in the axr1 gene result in a reduction in auxin response and diverse defects in auxin-regulated growth and development. in a previous study, we showed that axr1 forms a heterodimer with the ecr1 protein. this enzyme activates the ubiquitin-related protein rub1 in vitro. furthermore, we showed that the skp1-cul1/cdc53-f-box (scf) subunit atcul1 is modified by rub1 in vivo. in this report, we demonstrate that the formation of rub-atcul1 is dependent on axr1 and ecr1 in vivo. the expressi ... | 2002 | 11884684 |
| arabidopsis basic leucine zipper proteins that mediate stress-responsive abscisic acid signaling. | the phytohormone abscisic acid (aba) plays an essential role in adaptive stress responses. the hormone regulates, among others, the expression of numerous stress-responsive genes. from various promoter analyses, aba-responsive elements (abres) have been determined and a number of abre binding factors have been isolated, although their in vivo roles are not known. here we report that the abre binding factors abf3 and abf4 function in aba signaling. the constitutive overexpression of abf3 or abf4 ... | 2002 | 11884679 |
| antisense rna-mediated suppression of benzophenanthridine alkaloid biosynthesis in transgenic cell cultures of california poppy. | california poppy (eschscholzia californica cham.) cell cultures produce several benzophenanthridine alkaloids, such as sanguinarine, chelirubine, and macarpine, with potent pharmacological activity. antisense constructs of genes encoding two enzymes involved in benzophenanthridine alkaloid biosynthesis, the berberine bridge enzyme (bbe) and n-methylcoclaurine 3'-hydroxylase (cyp80b1), were introduced separately into california poppy cell cultures. transformed cell lines expressing antisense bbe ... | 2002 | 11842172 |
| temporal and spatial expression of a polygalacturonase during leaf and flower abscission in oilseed rape and arabidopsis. | during leaf abscission in oilseed rape (brassica napus), cell wall degradation is brought about by the action of several hydrolytic enzymes. one of these is thought to be polygalacturonase (pg). degenerate primers were used to isolate a pg cdna fragment by reverse transcriptase-polymerase chain reaction from rna extracted from ethylene-promoted leaf abscission zones (azs), and in turn a full-length clone (caw471) from an oilseed rape az cdna library. the highest homology of this cdna (82%) was t ... | 2002 | 11842157 |
| the plastidic pentose phosphate translocator represents a link between the cytosolic and the plastidic pentose phosphate pathways in plants. | plastids are the site of the reductive and the oxidative pentose phosphate pathways, which both generate pentose phosphates as intermediates. a plastidic transporter from arabidopsis has been identified that is able to transport, in exchange with inorganic phosphate or triose phosphates, xylulose 5-phosphate (xul-5-p) and, to a lesser extent, also ribulose 5-phosphate, but does not accept ribose 5-phosphate or hexose phosphates as substrates. under physiological conditions, xul-5-p would be the ... | 2002 | 11842155 |
| resistance against herbicide isoxaben and cellulose deficiency caused by distinct mutations in same cellulose synthase isoform cesa6. | isoxaben is a pre-emergence herbicide that inhibits cellulose biosynthesis in higher plants. two loci identified by isoxaben-resistant mutants (ixr1-1, ixr1-2, and ixr2-1) in arabidopsis have been reported previously. ixr1 was recently shown to encode the cellulose synthase catalytic subunit cesa3 (w.-r. scheible, r. eshed, t. richmond, d. delmer, and c. somerville [2001] proc natl acad sci usa 98: 10079-10084). here, we report on the cloning of ixr2, and show that it encodes another cellulose s ... | 2002 | 11842152 |
| 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 |
| molecular biology of stress responses. | | 2002 | 11892981 |
| all we are saying is give plants a chance! | | 2002 | 12488573 |
| a. thaliana transparent testa 1 is involved in seed coat development and defines the wip subfamily of plant zinc finger proteins. | seeds of the arabidopsis thaliana transparent testa 1 mutant (tt1) appear yellow, due to the lack of condensed tannin pigments in the seed coat. the tt1 gene was isolated by reverse genetics using an en-1 transposon mutagenized a. thaliana population. tt1 gene expression was detected in developing ovules and young seeds only, and the gene was shown to encode a nuclear protein. mutant seeds displayed altered morphology of the seed endothelium in which brown tannin pigments accumulate in wild-type ... | 2002 | 11782451 |
| rna silencing and the mobile silencing signal. | | 2002 | 12045284 |
| mutation of a chitinase-like gene causes ectopic deposition of lignin, aberrant cell shapes, and overproduction of ethylene. | chitinase-like proteins have long been proposed to play roles in normal plant growth and development, but no mutations in chitinase-like genes have been obtained previously to support this hypothesis. in this study, we have shown that the gene responsible for the elp1 mutation in arabidopsis encodes a chitinase-like protein (atctl1). mutation of this chitinase-like gene caused ectopic deposition of lignin and aberrant shapes of cells with incomplete cell walls in the pith of inflorescence stems. ... | 2002 | 11826306 |
| the arabidopsis spike1 gene is required for normal cell shape control and tissue development. | regulated growth and cell shape control are fundamentally important to the function of plant cells, tissues, and organs. the signal transduction cascades that control localized growth and cell shape, however, are not known. to better understand the relationship between cytoskeletal organization, organelle positioning, and regulated vesicle transport, we conducted a forward genetic screen to identify genes that regulate cytoskeletal organization in plants. because of the distinct requirements for ... | 2002 | 11826302 |
| arabidopsis rgl1 encodes a negative regulator of gibberellin responses. | in arabidopsis, the della subfamily of gras regulatory genes consists of gai, rga, rga-like1 (rgl1), rgl2, and rgl3. gai and rga are known to be negative regulators of gibberellin (ga) responses. we found that rgl1 is a similar repressor of ga responses, as revealed by rgl1 gain-of-function and loss-of-function phenotypes. repression of ga responses in arabidopsis was conferred by a dominant 35s-rgl1 transgene carrying a della domain deletion analogous to the ga-insensitive gai-1 mutation. as in ... | 2002 | 11826301 |
| the gibberellin signaling pathway is regulated by the appearance and disappearance of slender rice1 in nuclei. | the slender rice1 mutant (slr1) shows a constitutive gibberellin (ga) response phenotype. to investigate the mode of action of slr1, we generated transgenic rice expressing a fusion protein consisting of slr1 and green fluorescent protein (slr1-gfp) and analyzed the phenotype of the transformants and the subcellular localization of gfp in vivo. slr1-gfp worked in nuclei to repress the ga signaling pathway; its overproduction caused a dwarf phenotype. application of ga(3) to slr1-gfp overproducer ... | 2002 | 11826299 |
| differential regulation of mrna levels of acyl carrier protein isoforms in arabidopsis. | all higher plants express several different acyl carrier protein (acp) isoforms in a tissue-specific manner. we provide evidence that expression of mrna for the most abundant acp isoform in arabidopsis leaves (acp4) is increased severalfold by light, whereas mrna levels for acp isoforms 2 and 3 are independent of light. the presence of gata-like motifs in the upstream region of the acl1.4 gene (encoding for acp4) and the similarity in light-mediated induction to ferredoxin-a mrna suggests a dire ... | 2002 | 11788768 |
| distinct but conserved functions for two chloroplastic nadp-malic enzyme isoforms in c3 and c4 flaveria species. | in the most common c4 pathway for carbon fixation, an nadp-malic enzyme (nadp-me) decarboxylates malate in the chloroplasts of bundle sheath cells. isoforms of plastidic nadp-me are encoded by two genes in all species of flaveria, including c3, c3-c4 intermediate, and c4 types. however, only one of these genes, chlme1, encodes the enzyme that functions in the c4 pathway. we compared the expression patterns of the chlme1 and chlme2 genes in developing leaves of flaveria pringlei (c3) and flaveria ... | 2002 | 11788758 |
| constitutive overexpression of cystathionine gamma-synthase in arabidopsis leads to accumulation of soluble methionine and s-methylmethionine. | the committing step in met and s-adenosyl-l-met (sam) synthesis is catalyzed by cystathionine gamma-synthase (cgs). transgenic arabidopsis plants overexpressing cgs under control of the cauliflower mosaic virus 35s promoter show increased soluble met and its metabolite s-methyl-met, but only at specific stages of development. the highest level of met and s-methyl-met was observed in seedling tissues and in flowers, siliques, and roots of mature plants where they accumulate 8- to 20-fold above wi ... | 2002 | 11788756 |
| altered levels of proline dehydrogenase cause hypersensitivity to proline and its analogs in arabidopsis. | pro dehydrogenase (pdh) catalyzes the first and rate-limiting step in the pro catabolic pathway. in arabidopsis, this enzyme is encoded by at-pdh. to investigate the role of pro catabolism in plants, we generated transgenic arabidopsis plants with altered levels of pdh by sense (pdh-s plants) and antisense (pdh-as plants) strategies. free pro levels were reduced by up to 50% in pdh-s plants under stress and recovery conditions and enhanced by a maximum of 25% in pdh-as plants, despite large modi ... | 2002 | 11788754 |
| flagdb/fst: a database of mapped flanking insertion sites (fsts) of arabidopsis thaliana t-dna transformants. | a large collection of t-dna insertion transformants of arabidopsis thaliana has been generated at the institute of agronomic research, versailles, france. the molecular characterisation of the insertion sites is currently performed by sequencing genomic regions flanking the inserted t-dna (fst). the almost complete sequence of the nuclear genome of a.thaliana provides the framework for organising fsts in a genome oriented database, flagdb/fst (http://genoplante-info.infobiogen.fr). the main scop ... | 2002 | 11752264 |
| genbank. | the genbank sequence database incorporates publicly available dna sequences of more than 105 000 different organisms, primarily through direct submission of sequence data from individual laboratories and large-scale sequencing projects. most submissions are made using the bankit (web) or sequin programs and accession numbers are assigned by genbank staff upon receipt. data exchange with the embl data library and the dna data bank of japan helps ensure comprehensive worldwide coverage. genbank da ... | 2002 | 11752243 |