| roles of arabidopsis wrky18, wrky40 and wrky60 transcription factors in plant responses to abscisic acid and abiotic stress. | wrky transcription factors are involved in plant responses to both biotic and abiotic stresses. arabidopsis wrky18, wrky40, and wrky60 transcription factors interact both physically and functionally in plant defense responses. however, their role in plant abiotic stress response has not been directly analyzed. | 2010 | 21167067 |
| siz1 regulation of phosphate starvation-induced root architecture remodeling involves the control of auxin accumulation. | phosphate (pi) limitation causes plants to modulate the architecture of their root systems to facilitate the acquisition of pi. previously, we reported that the arabidopsis (arabidopsis thaliana) sumo e3 ligase siz1 regulates root architecture remodeling in response to pi limitation; namely, the siz1 mutations cause the inhibition of primary root (pr) elongation and the promotion of lateral root (lr) formation. here, we present evidence that siz1 is involved in the negative regulation of auxin p ... | 2010 | 21156857 |
| siz1 regulation of phosphate starvation-induced root architecture remodeling involves the control of auxin accumulation. | phosphate (pi) limitation causes plants to modulate the architecture of their root systems to facilitate the acquisition of pi. previously, we reported that the arabidopsis (arabidopsis thaliana) sumo e3 ligase siz1 regulates root architecture remodeling in response to pi limitation; namely, the siz1 mutations cause the inhibition of primary root (pr) elongation and the promotion of lateral root (lr) formation. here, we present evidence that siz1 is involved in the negative regulation of auxin p ... | 2010 | 21156857 |
| kinome profiling reveals an interaction between jasmonate, salicylate and light control of hyponastic petiole growth in arabidopsis thaliana. | plants defend themselves against infection by biotic attackers by producing distinct phytohormones. especially jasmonic acid (ja) and salicylic acid (sa) are well known defense-inducing hormones. here, the effects of meja and sa on the arabidopsis thaliana kinome were monitored using pepchip arrays containing kinase substrate peptides to analyze posttranslational interactions in meja and sa signaling pathways and to test if kinome profiling can provide leads to predict posttranslational events i ... | 2010 | 21170386 |
| large-scale chromatin de-compaction induced by low light is not accompanied by nucleosomal displacement. | arabidopsis thaliana is widely used as model to study chromatin compaction dynamics during development and in response to the environment. signals such as prolonged heat treatment, low light and pathogen infestation are known to induce large-scale de-condensation of nuclear chromatin. here we demonstrate that the response to different environments varies at the nucleosomal level. our results show that in contrast to previous reports on heat and biotic infestation, low light intensity signaling d ... | 2010 | 21139439 |
| modulating plant hormones by enzyme action: the gh3 family of acyl acid amido synthetases. | plants respond to developmental cues and environmental stresses by controlling both the level and activity of various hormones. one mechanism of modulating hormone action involves amino acid conjugation. in plants, the gh3 family of enzymes conjugates various amino acids to jasmonates, auxins, and benzoates. the effect of conjugation can lead to activation, inactivation, or degradation of these molecules. although the acyl acid and amino acid specificities of a few gh3 enzymes have been examined ... | 2010 | 21150301 |
| two vacuole-mediated defense strategies in plants. | as plants lack immune cells, each cell has to defend itself against invading pathogens. plant cells have a large central vacuole that accumulates a variety of hydrolytic enzymes and antimicrobial compounds, raising the possibility that vacuoles play a role in plant defense. however, how plants use vacuoles to protect against invading pathogens is poorly understood. recently, we characterized two vacuole-mediated defense strategies associated with programmed cell death (pcd). in one strategy, vac ... | 2010 | 21512325 |
| the role of vacuolar processing enzymes in plant immunity. | proteases play important roles in plant innate immunity. in this mini-review, we describe the current view on the role of a plant protease, vacuolar processing enzyme (vpe), and the first identified plant caspase-1-like protein, in plant immunity. in the past several years, vpes were determined to play important roles in various types of cell death in plants. early studies demonstrated the identification of vpe as a vacuolar hydrolytic protein responsible for maturation of vacuolar proteins. lat ... | 2010 | 21139432 |
| in silico identification of coffee genome expressed sequences potentially associated with resistance to diseases. | sequences potentially associated with coffee resistance to diseases were identified by in silico analyses using the database of the brazilian coffee genome project (bcgp). keywords corresponding to plant resistance mechanisms to pathogens identified in the literature were used as baits for data mining. expressed sequence tags (ests) related to each of these keywords were identified with tools available in the bcgp bioinformatics platform. a total of 11,300 ests were mined. these ests were cluste ... | 2010 | 21637594 |
| the plant apoplasm is an important recipient compartment for nematode secreted proteins. | similarly to microbial pathogens, plant-parasitic nematodes secrete into their host plants proteins that are essential to establish a functional interaction. identifying the destination of nematode secreted proteins within plant cell compartment(s) will provide compelling clues on their molecular functions. here the fine localization of five nematode secreted proteins was analysed throughout parasitism in arabidopsis thaliana. an immunocytochemical method was developed that preserves both the ho ... | 2010 | 21115667 |
| the plant apoplasm is an important recipient compartment for nematode secreted proteins. | similarly to microbial pathogens, plant-parasitic nematodes secrete into their host plants proteins that are essential to establish a functional interaction. identifying the destination of nematode secreted proteins within plant cell compartment(s) will provide compelling clues on their molecular functions. here the fine localization of five nematode secreted proteins was analysed throughout parasitism in arabidopsis thaliana. an immunocytochemical method was developed that preserves both the ho ... | 2010 | 21115667 |
| amino acid homeostasis modulates salicylic acid-associated redox status and defense responses in arabidopsis. | the tight association between nitrogen status and pathogenesis has been broadly documented in plant-pathogen interactions. however, the interface between primary metabolism and disease responses remains largely unclear. here, we show that knockout of a single amino acid transporter, lysine histidine transporter1 (lht1), is sufficient for arabidopsis thaliana plants to confer a broad spectrum of disease resistance in a salicylic acid-dependent manner. we found that redox fine-tuning in photosynth ... | 2010 | 21097712 |
| herbivore-induced and floral homoterpene volatiles are biosynthesized by a single p450 enzyme (cyp82g1) in arabidopsis. | terpene volatiles play important roles in plant-organism interactions as attractants of pollinators or as defense compounds against herbivores. among the most common plant volatiles are homoterpenes, which are often emitted from night-scented flowers and from aerial tissues upon herbivore attack. homoterpene volatiles released from herbivore-damaged tissue are thought to contribute to indirect plant defense by attracting natural enemies of pests. moreover, homoterpenes have been demonstrated to ... | 2010 | 21088219 |
| ca2+ signaling by plant arabidopsis thaliana pep peptides depends on atpepr1, a receptor with guanylyl cyclase activity, and cgmp-activated ca2+ channels. | a family of peptide signaling molecules (atpeps) and their plasma membrane receptor atpepr1 are known to act in pathogen-defense signaling cascades in plants. little is currently known about the molecular mechanisms that link these signaling peptides and their receptor, a leucine-rich repeat receptor-like kinase, to downstream pathogen-defense responses. we identify some cellular activities of these molecules that provide the context for a model for their action in signaling cascades. atpeps act ... | 2010 | 21088220 |
| cyanide, a coproduct of plant hormone ethylene biosynthesis, contributes to the resistance of rice to blast fungus. | rice (oryza sativa) plants carrying the pi-i resistance gene to blast fungus magnaporthe oryzae restrict invaded fungus in infected tissue via hypersensitive reaction or response (hr), which is accompanied by rapid ethylene production and formation of small hr lesions. ethylene biosynthesis has been implicated to be important for blast resistance; however, the individual roles of ethylene and cyanide, which are produced from the precursor 1-aminocyclopropane-1-carboxylic acid, remain unevaluated ... | 2010 | 21075959 |
| cyanide, a coproduct of plant hormone ethylene biosynthesis, contributes to the resistance of rice to blast fungus. | rice (oryza sativa) plants carrying the pi-i resistance gene to blast fungus magnaporthe oryzae restrict invaded fungus in infected tissue via hypersensitive reaction or response (hr), which is accompanied by rapid ethylene production and formation of small hr lesions. ethylene biosynthesis has been implicated to be important for blast resistance; however, the individual roles of ethylene and cyanide, which are produced from the precursor 1-aminocyclopropane-1-carboxylic acid, remain unevaluated ... | 2010 | 21075959 |
| proline metabolism and its implications for plant-environment interaction. | proline has long been known to accumulate in plants experiencing water limitation and this has driven studies of proline as a beneficial solute allowing plants to increase cellular osmolarity during water limitation. proline metabolism also has roles in redox buffering and energy transfer and is involved in plant pathogen interaction and programmed cell death. some of these unique roles of proline depend on the properties of proline itself, whereas others depend on the "proline cycle" of coordin ... | 2010 | 22303265 |
| snp discovery and linkage map construction in cultivated tomato. | few intraspecific genetic linkage maps have been reported for cultivated tomato, mainly because genetic diversity within solanum lycopersicum is much less than that between tomato species. single nucleotide polymorphisms (snps), the most abundant source of genomic variation, are the most promising source of polymorphisms for the construction of linkage maps for closely related intraspecific lines. in this study, we developed snp markers based on expressed sequence tags for the construction of in ... | 2010 | 21044984 |
| biology by design: from top to bottom and back. | synthetic biology is a nascent technical discipline that seeks to enable the design and construction of novel biological systems to meet pressing societal needs. however, engineering biology still requires much trial and error because we lack effective approaches for connecting basic "parts" into higher-order networks that behave as predicted. developing strategies for improving the performance and sophistication of our designs is informed by two overarching perspectives: "bottom-up" and "top-do ... | 2010 | 21052559 |
| bacterial nanomachines: the flagellum and type iii injectisome. | the bacterial flagellum and the virulence-associated injectisome are complex, structurally related nanomachines that bacteria use for locomotion or the translocation of virulence factors into eukaryotic host cells. the assembly of both structures and the transfer of extracellular proteins is mediated by a unique, multicomponent transport apparatus, the type iii secretion system. here, we discuss the significant progress that has been made in recent years in the visualization and functional chara ... | 2010 | 20926516 |
| computational prediction of type iii and iv secreted effectors in gram-negative bacteria. | in this review, we provide an overview of the methods employed in four recent studies that described novel methods for computational prediction of secreted effectors from type iii and iv secretion systems in gram-negative bacteria. we present the results of these studies in terms of performance at accurately predicting secreted effectors and similarities found between secretion signals that may reflect biologically relevant features for recognition. we discuss the web-based tools for secreted ef ... | 2010 | 20974833 |
| computational prediction of type iii and iv secreted effectors in gram-negative bacteria. | in this review, we provide an overview of the methods employed in four recent studies that described novel methods for computational prediction of secreted effectors from type iii and iv secretion systems in gram-negative bacteria. we present the results of these studies in terms of performance at accurately predicting secreted effectors and similarities found between secretion signals that may reflect biologically relevant features for recognition. we discuss the web-based tools for secreted ef ... | 2010 | 20974833 |
| a computational-based update on micrornas and their targets in barley (hordeum vulgare l.). | many plant species have been investigated in the last years for the identification and characterization of the corresponding mirnas, nevertheless extensive studies are not yet available on barley (at the time of this writing). to extend and to update information on mirnas and their targets in barley and to identify candidate polymorphisms at mirna target sites, the features of previously known plant mirnas have been used to systematically search for barley mirna homologues and targets in the pub ... | 2010 | 20969764 |
| systematizing the generation of missing metabolic knowledge. | genome-scale metabolic network reconstructions are built from all of the known metabolic reactions and genes in a target organism. however, since our knowledge of any organism is incomplete, these network reconstructions contain gaps. reactions may be missing, resulting in dead-ends in pathways, while unknown gene products may catalyze known reactions. new computational methods that analyze data, such as growth phenotypes or gene essentiality, in the context of genome-scale metabolic networks, h ... | 2010 | 20589842 |
| t3sedb: data warehousing of virulence effectors secreted by the bacterial type iii secretion system. | effectors of type iii secretion system (t3ss) play a pivotal role in establishing and maintaining pathogenicity in the host and therefore the identification of these effectors is important in understanding virulence. however, the effectors display high level of sequence diversity, therefore making the identification a difficult process. there is a need to collate and annotate existing effector sequences in public databases to enable systematic analyses of these sequences for development of model ... | 2010 | 21106126 |
| global transcript profiling of transgenic plants constitutively overexpressing the rna-binding protein atgrp7. | the clock-controlled rna-binding protein atgrp7 influences circadian oscillations of its own transcript at the post-transcriptional level. to identify additional targets that are regulated by atgrp7, transcript profiles of transgenic plants constitutively overexpressing atgrp7 (atgrp7-ox) and wild type plants were compared. | 2010 | 20946635 |
| two putative rna-binding proteins function with unequal genetic redundancy in the mos4-associated complex. | the mos4-associated complex (mac) is a highly conserved nuclear protein complex associated with the spliceosome. we recently purified the mac from arabidopsis (arabidopsis thaliana) nuclei, identified its potential components by mass spectrometry, and showed that at least five core proteins in the mac are required for defense responses in plants. here, we report the characterization of a putative rna-binding protein identified in the mac named mac5a and its close homolog mac5b. we confirmed that ... | 2010 | 20943852 |
| an effector-targeted protease contributes to defense against phytophthora infestans and is under diversifying selection in natural hosts. | since the leaf apoplast is a primary habitat for many plant pathogens, apoplastic proteins are potent, ancient targets for apoplastic effectors secreted by plant pathogens. so far, however, only a few apoplastic effector targets have been identified and characterized. here, we discovered that the papain-like cysteine protease c14 is a new common target of epic1 and epic2b, two apoplastic, cystatin-like proteins secreted by the potato (solanum tuberosum) late blight pathogen phytophthora infestan ... | 2010 | 20940351 |
| photoreceptors crytochrome2 and phytochrome b control chromatin compaction in arabidopsis. | development and acclimation processes to the environment are associated with large-scale changes in chromatin compaction in arabidopsis (arabidopsis thaliana). here, we studied the effects of light signals on chromatin organization. a decrease in light intensity induces a large-scale reduction in chromatin compaction. this low light response is reversible and shows strong natural genetic variation. moreover, the degree of chromatin compaction is affected by light quality signals relevant for nat ... | 2010 | 20935177 |
| autoimmunity in arabidopsis acd11 is mediated by epigenetic regulation of an immune receptor. | certain pathogens deliver effectors into plant cells to modify host protein targets and thereby suppress immunity. these target modifications can be detected by intracellular immune receptors, or resistance (r) proteins, that trigger strong immune responses including localized host cell death. the accelerated cell death 11 (acd11) "lesion mimic" mutant of arabidopsis thaliana exhibits autoimmune phenotypes such as constitutive defense responses and cell death without pathogen perception. acd11 e ... | 2010 | 20949080 |
| jasmonate perception by inositol-phosphate-potentiated coi1-jaz co-receptor. | jasmonates are a family of plant hormones that regulate plant growth, development and responses to stress. the f-box protein coronatine insensitive 1 (coi1) mediates jasmonate signalling by promoting hormone-dependent ubiquitylation and degradation of transcriptional repressor jaz proteins. despite its importance, the mechanism of jasmonate perception remains unclear. here we present structural and pharmacological data to show that the true arabidopsis jasmonate receptor is a complex of both coi ... | 2010 | 20927106 |
| pathogen-associated molecular pattern-triggered immunity: veni, vidi...? | | 2010 | 20921183 |
| control of salicylic acid synthesis and systemic acquired resistance by two members of a plant-specific family of transcription factors. | salicylic acid (sa) is a defense hormone required for both local and systemic acquired resistance (sar) in plants. pathogen infections induce sa synthesis through up-regulating the expression of isochorismate synthase 1 (ics1), which encodes a key enzyme in sa production. here we report that both sar deficient 1 (sard1) and cbp60g are key regulators for ics1 induction and sa synthesis. whereas knocking out sard1 compromises basal resistance and sar, overexpression of sard1 constitutively activat ... | 2010 | 20921422 |
| extracellular atp signaling in plants. | extracellular adenosine-5'-triphosphate (atp) induces a number of cellular responses in plants and animals. some of the molecular components for purinergic signaling in animal cells appear to be lacking in plant cells, although some cellular responses are similar in both systems [e.g. increased levels of cytosolic free calcium, nitric oxide (no), and reactive oxygen species (ros)]. the purpose of this review is to compare and contrast purinergic signaling mechanisms in animal and plant cells. th ... | 2010 | 20817461 |
| sa-aba antagonism in defense responses. | until recently, phytohormones were mostly studied separately. however, recent studies have suggested that the signaling pathways involved are highly interconnected. we recently reported the antagonistic effects of salicylic acid (sa) and abscisic acid (aba) in the lesion mimic mutants, cpr22 and ssi4. after shifting these mutants from high humidity, where the lesion mimic phenotype is suppressed to permissive low humidity condition, both sa and aba pathways were up-regulated. however, the increa ... | 2010 | 20861686 |
| the interplay of lipid acyl hydrolases in inducible plant defense. | lipid acyl hydrolases (lah) have received recently increased attention in the context of plant defense. multiple structurally unrelated gene families have been annotated in arabidopsis as encoding potential lipid deacylating enzymes with numerous members being transcriptionally activated upon biotic stress. confirming in silico predictions, experimental data have illustrated the wide subcellular distribution of lahs indicating they likely interact with distinct membrane systems to initiate speci ... | 2010 | 20861688 |
| studying bacterial transcriptomes using rna-seq. | genome-wide studies of bacterial gene expression are shifting from microarray technology to second generation sequencing platforms. rna-seq has a number of advantages over hybridization-based techniques, such as annotation-independent detection of transcription, improved sensitivity and increased dynamic range. early studies have uncovered a wealth of novel coding sequences and non-coding rna, and are revealing a transcriptional landscape that increasingly mirrors that of eukaryotes. already bas ... | 2010 | 20888288 |
| interaction of 8-hydroxyquinoline with soil environment mediates its ecological function. | allelopathic functions of plant-released chemicals are often studied through growth bioassays assuming that these chemicals will directly impact plant growth. this overlooks the role of soil factors in mediating allelopathic activities of chemicals, particularly non-volatiles. here we examined the allelopathic potential of 8-hydroxyquinoline (hq), a chemical reported to be exuded from the roots of centaurea diffusa. | 2010 | 20877629 |
| pamp (pathogen-associated molecular pattern)-induced changes in plasma membrane compartmentalization reveal novel components of plant immunity. | plasma membrane compartmentalization spatiotemporally regulates cell-autonomous immune signaling in animal cells. to elucidate immediate early protein dynamics at the plant plasma membrane in response to the bacterial pathogen-associated molecular pattern (pamp) flagellin (flg22) we employed quantitative mass spectrometric analysis on detergent-resistant membranes (drms) of arabidopsis thaliana suspension cells. this approach revealed rapid and profound changes in drm protein composition followi ... | 2010 | 20843791 |
| high-throughput confocal imaging of intact live tissue enables quantification of membrane trafficking in arabidopsis. | membrane compartmentalization and trafficking within and between cells is considered an essential cellular property of higher eukaryotes. we established a high-throughput imaging method suitable for the quantitative detection of membrane compartments at subcellular resolution in intact epidermal tissue. whole arabidopsis (arabidopsis thaliana) cotyledon leaves were subjected to quantitative confocal laser microscopy using automated image acquisition, computational pattern recognition, and quanti ... | 2010 | 20841454 |
| arabidopsis snc2-1d activates receptor-like protein-mediated immunity transduced through wrky70. | plant immune receptors belonging to the receptor-like protein (rlp) family contain extracellular leucine-rich repeats (lrrs) and a short cytoplasmic tail linked by a single transmembrane motif. here, we report the identification of snc2-1d (for suppressor of npr1-1, constitutive 2), a semidominant arabidopsis thaliana mutant with constitutively activated defense responses. map-based cloning of snc2-1d showed that it encodes an rlp. the point mutation in snc2-1d leads to substitution of the secon ... | 2010 | 20841424 |
| aba-dependent amine oxidases-derived h2o2 affects stomata conductance. | recently we showed that aba is at least partly responsible for the induction of the polyamine exodus pathway in vitis vinifera plants. both sensitive and tolerant plants employ this pathway to orchestrate stress responses, differing between stress adaptation and programmed cell death. herein we show that aba is an upstream signal for the induction of the polyamine catabolic pathway in vitis vinifera. thus, amine oxidases are producing h2o2 which signals stomata closure. moreover, the previously ... | 2010 | 21490422 |
| in search of decoy/guardee to r genes: deciphering the role of sugars in defense against fusarium wilt in chickpea. | plant responses are coordinately controlled by both external and internal signals. apt perception of pathogen attack and its appropriate conversion to internal signals ultimately determine the outcome of innate immunity. the present review predicts the involvement of unconventional 'guard/decoy model' in chickpea-fusarium encounter. rapid alkalinization factor is predicted to act as initial 'gatekeeper decoy' counteracting fungal entry. phospholipases and cystatins probably function as 'guardees ... | 2010 | 20855953 |
| plant physiology. on the inside. | | 2010 | 20836252 |
| gene expression browser: large-scale and cross-experiment microarray data integration, management, search & visualization. | in the last decade, a large amount of microarray gene expression data has been accumulated in public repositories. integrating and analyzing high-throughput gene expression data have become key activities for exploring gene functions, gene networks and biological pathways. effectively utilizing these invaluable microarray data remains challenging due to a lack of powerful tools to integrate large-scale gene-expression information across diverse experiments and to search and visualize a large num ... | 2010 | 20727159 |
| nicotiana attenuata nahd20 plays a role in leaf aba accumulation during water stress, benzylacetone emission from flowers, and the timing of bolting and flower transitions. | homeodomain-leucine zipper type i (hd-zip i) proteins are plant-specific transcription factors associated with the regulation of growth and development in response to changes in the environment. nicotiana attenuata nahd20 was identified as an hd-zip i-coding gene whose expression was induced by multiple stress-associated stimuli including drought and wounding. to study the role of nahd20 in the integration of stress responses with changes in growth and development, its expression was silenced by ... | 2010 | 20713465 |
| nicotiana attenuata nahd20 plays a role in leaf aba accumulation during water stress, benzylacetone emission from flowers, and the timing of bolting and flower transitions. | homeodomain-leucine zipper type i (hd-zip i) proteins are plant-specific transcription factors associated with the regulation of growth and development in response to changes in the environment. nicotiana attenuata nahd20 was identified as an hd-zip i-coding gene whose expression was induced by multiple stress-associated stimuli including drought and wounding. to study the role of nahd20 in the integration of stress responses with changes in growth and development, its expression was silenced by ... | 2010 | 20713465 |
| modulation of redox homeostasis under suboptimal conditions by arabidopsis nudix hydrolase 7. | nudix hydrolases play a key role in maintaining cellular homeostasis by hydrolyzing various nuceloside diphosphate derivatives and capped mrnas. several independent studies have demonstrated that arabidopsis nudix hydrolase 7 (atnudt7) hydrolyzes nadh and adp-ribose. loss of function atnudt7-1 mutant plants (salk_046441) exhibit stunted growth, higher levels of reactive oxygen species, enhanced resistance to pathogens. however, using the same t-dna line, two other groups reported that mutant pla ... | 2010 | 20704736 |
| the glabra1 mutation affects cuticle formation and plant responses to microbes. | systemic acquired resistance (sar) is a form of defense that provides resistance against a broad spectrum of pathogens in plants. previous work indicates a role for plastidial glycerolipid biosynthesis in sar. specifically, mutations in fatty acid desaturase7 (fad7), which lead to reduced trienoic fatty acid levels and compromised plastidial lipid biosynthesis, have been associated with defective sar. we show that the defective sar in arabidopsis (arabidopsis thaliana) fad7-1 plants is not assoc ... | 2010 | 20699396 |
| identification and partial characterization of an l-tyrosine aminotransferase (tat) from arabidopsis thaliana. | the aminotransferase gene family in the model plant arabidopsis thaliana consists of 44 genes. twenty six of these enzymes are classified as characterized meaning that the reaction(s) that the enzyme catalyzes are documented using experimental means. the remaining 18 enzymes are uncharacterized and are therefore deemed putative. our laboratory is interested in elucidating the function(s) of the remaining putative aminotransferase enzymes. to this end, we have identified and partially characteriz ... | 2010 | 21188077 |
| root secretion of defense-related proteins is development-dependent and correlated with flowering time. | proteins found in the root exudates are thought to play a role in the interactions between plants and soil organisms. to gain a better understanding of protein secretion by roots, we conducted a systematic proteomic analysis of the root exudates of arabidopsis thaliana at different plant developmental stages. in total, we identified 111 proteins secreted by roots, the majority of which were exuded constitutively during all stages of development. however, defense-related proteins such as chitinas ... | 2010 | 20682788 |
| direct transcriptional control of the arabidopsis immune receptor fls2 by the ethylene-dependent transcription factors ein3 and eil1. | in plant innate immunity, the leucine-rich repeat receptor kinase fls2 recognizes the bacterial pathogen-associated molecular pattern (pamp) flagellin. the molecular mechanisms underlying pamp perception are not fully understood. here, we reveal that the gaseous phytohormone ethylene is an integral part of pamp-triggered immunity. plants mutated in the key ethylene-signaling protein ein2 are impaired in all fls2-mediated responses, correlating with reduced fls2 transcription and protein accumula ... | 2010 | 20663954 |
| arabidopsis resistance protein snc1 activates immune responses through association with a transcriptional corepressor. | in both plants and animals, nucleotide-binding (nb) domain and leucine-rich repeat (lrr)-containing proteins (nlr) function as sensors of pathogen-derived molecules and trigger immune responses. although nlr resistance (r) proteins were first reported as plant immune receptors more than 15 years ago, how these proteins activate downstream defense responses is still unclear. here we report that the toll-like/interleukin-1 receptor (tir)-nb-lrr r protein, suppressor of npr1-1, constitutive 1 (snc1 ... | 2010 | 20647385 |
| evidence for light wavelength-specific photoelectrophysiological signaling and memory of excess light episodes in arabidopsis. | although light is essential for photosynthesis, excess light can damage the photosynthetic apparatus and deregulate other cellular processes. thus, protective integrated regulatory responses that can dissipate excess of absorbed light energy and simultaneously optimize photosynthesis and other cellular processes under variable light conditions can prove highly adaptive. here, we show that the local and systemic responses to an excess light episode are associated with photoelectrophysiological si ... | 2010 | 20639446 |
| sirnas from mirna sites mediate dna methylation of target genes. | arabidopsis microrna (mirna) genes (mir) give rise to 20- to 22-nt mirnas that are generated predominantly by the type iii endoribonuclease dicer-like 1 (dcl1) but do not require any rna-dependent rna polymerases (rdrs) or rna polymerase iv (pol iv). here, we identify a novel class of non-conserved mir genes that give rise to two small rna species, a 20- to 22-nt species and a 23- to 27-nt species, at the same site. genetic analysis using small rna pathway mutants reveals that the 20- to 22-nt s ... | 2010 | 20621980 |
| tossed salads. | | 2010 | 21327036 |
| overexpression of the epidermis-specific homeodomain-leucine zipper iv transcription factor outer cell layer1 in maize identifies target genes involved in lipid metabolism and cuticle biosynthesis. | transcription factors of the homeodomain-leucine zipper iv (hd-zip iv) family play crucial roles in epidermis-related processes. to gain further insight into the molecular function of outer cell layer1 (ocl1), 14 target genes up- or down-regulated in transgenic maize (zea mays) plants overexpressing ocl1 were identified. the 14 genes all showed partial coexpression with ocl1 in maize organs, and several of them shared preferential expression in the epidermis with ocl1. they encoded proteins invo ... | 2010 | 20605912 |
| towards elucidating the differential regulation of floral and extrafloral nectar secretion. | nectar is a rich source of sugars that serves the attraction of pollinators (floral nectar) or predatory arthropods (extrafloral nectar). we just begin to understand the similarities and differences that underlie the secretory control of these two important types of plant secretions. jasmonates are phytohormones, which are well documented to be involved in plant developmental processes and plant defence responses against herbivores, including the secretion of extrafloral nectar. recently, jasmon ... | 2010 | 20622524 |
| investigating the function of caf1 deadenylases during plant stress responses. | alteration of gene expression plays a central role in the transmission of developmental and environmental signals. the steady-state transcript level within a cell is determined by the combination of the rate synthesis and the rate of degradation. while altering the rate of mrna turnover is known to provide a rapid mechanism to reprogram transcript levels, research has largely focused on changes in transcriptional regulation as a mechanism to control mrna levels. however, recent studies have begu ... | 2010 | 20421740 |
| differential expression of maize chitinases in the presence or absence of trichoderma harzianum strain t22 and indications of a novel exo- endo-heterodimeric chitinase activity. | the interaction of plants with endophytic symbiotic fungi in the genus trichoderma alters the plant proteome and transcriptome and results in enhanced plant growth and resistance to diseases. in a previous study, we identified the numerous chitinolytic enzyme families and individual enzymes in maize which are implicated in plant disease resistance and other plant responses. | 2010 | 20594307 |
| on the possible role of robustness in the evolution of infectious diseases. | robustness describes the capacity for a biological system to remain canalized despite perturbation. genetic robustness affords maintenance of phenotype despite mutational input, necessarily involving the role of epistasis. environmental robustness is phenotypic constancy in the face of environmental variation, where epistasis may be uninvolved. here we discuss genetic and environmental robustness, from the standpoint of infectious disease evolution, and suggest that robustness may be a unifying ... | 2010 | 20590337 |
| rna-seq analysis of sulfur-deprived chlamydomonas cells reveals aspects of acclimation critical for cell survival. | the chlamydomonas reinhardtii transcriptome was characterized from nutrient-replete and sulfur-depleted wild-type and snrk2.1 mutant cells. this mutant is null for the regulatory ser-thr kinase snrk2.1, which is required for acclimation of the alga to sulfur deprivation. the transcriptome analyses used microarray hybridization and rna-seq technology. quantitative rt-pcr evaluation of the results obtained by these techniques showed that rna-seq reports a larger dynamic range of expression levels ... | 2010 | 20587772 |
| sopra: scaffolding algorithm for paired reads via statistical optimization. | high throughput sequencing (hts) platforms produce gigabases of short read (<100 bp) data per run. while these short reads are adequate for resequencing applications, de novo assembly of moderate size genomes from such reads remains a significant challenge. these limitations could be partially overcome by utilizing mate pair technology, which provides pairs of short reads separated by a known distance along the genome. | 2010 | 20576136 |
| plant stomata: a checkpoint of host immunity and pathogen virulence. | stomata are microscopic pores formed by pairs of guard cells in the epidermis of terrestrial plants; they are essential for gas exchange with the environment and controlling water loss. accordingly, plants regulate stomatal aperture in response to environmental conditions, such as relative humidity, co(2) concentration, and light intensity. stomatal openings are also a major route of pathogen entry into the plant and plants have evolved mechanisms to regulate stomatal aperture as an immune respo ... | 2010 | 20573499 |
| what's in a name? the semantics of quorum sensing. | the expression of many bacterial phenotypes is regulated according to the concentration of chemical cues that they or other bacteria produce, a process often termed quorum sensing (qs). many aspects of the environment can affect cue concentration. thus these molecules might be indirect proxies for any one or combination of environmental factors. recent research suggests that the adaptive significance of qs varies depending on its evolutionary and ecological context. consequently, some researcher ... | 2010 | 20573513 |
| short signalling distances make plant communication a soliloquy. | plants respond to attack by herbivores or pathogens with the release of volatile organic compounds. neighbouring plants can receive these volatiles and consecutively induce their own defence arsenal. this 'plant communication', however, appears counterintuitive when it benefits independent and genetically unrelated receivers, which may compete with the emitter. as a solution to this problem, a role for volatile compounds in within-plant signalling has been predicted. we used wild-type lima bean ... | 2010 | 20554558 |
| do apicomplexan parasites hijack the host cell microrna pathway for their intracellular development? | rna silencing plays an important role in development through the action of micrornas, which fine tune the expression of a large portion of the genome. it is also very important in innate immune responses, especially in antiviral and antibacterial defenses in plants, insects, and animals. two recent papers now indicate that apicomplexan parasites display the ability to interfere with host microrna populations. | 2010 | 20948791 |
| an mrna blueprint for c4 photosynthesis derived from comparative transcriptomics of closely related c3 and c4 species. | c(4) photosynthesis involves alterations to the biochemistry, cell biology, and development of leaves. together, these modifications increase the efficiency of photosynthesis, and despite the apparent complexity of the pathway, it has evolved at least 45 times independently within the angiosperms. to provide insight into the extent to which gene expression is altered between c(3) and c(4) leaves, and to identify candidates associated with the c(4) pathway, we used massively parallel mrna sequenc ... | 2010 | 20543093 |
| an mrna blueprint for c4 photosynthesis derived from comparative transcriptomics of closely related c3 and c4 species. | c(4) photosynthesis involves alterations to the biochemistry, cell biology, and development of leaves. together, these modifications increase the efficiency of photosynthesis, and despite the apparent complexity of the pathway, it has evolved at least 45 times independently within the angiosperms. to provide insight into the extent to which gene expression is altered between c(3) and c(4) leaves, and to identify candidates associated with the c(4) pathway, we used massively parallel mrna sequenc ... | 2010 | 20543093 |
| accumulation of isochorismate-derived 2,3-dihydroxybenzoic 3-o-beta-d-xyloside in arabidopsis resistance to pathogens and ageing of leaves. | an intricate network of hormone signals regulates plant development and responses to biotic and abiotic stress. salicylic acid (sa), derived from the shikimate/isochorismate pathway, is a key hormone in resistance to biotrophic pathogens. several sa derivatives and associated modifying enzymes have been identified and implicated in the storage and channeling of benzoic acid intermediates or as bioactive molecules. however, the range and modes of action of sa-related metabolites remain elusive. i ... | 2010 | 20538606 |
| cryo-electron tomography of bacteriophage phi6 procapsids shows random occupancy of the binding sites for rna polymerase and packaging ntpase. | assembly of dsrna bacteriophage phi6 involves packaging of the three mrna strands of the segmented genome into the procapsid, an icosahedrally symmetric particle with recessed vertices. the hexameric packaging ntpase (p4) overlies these vertices, and the monomeric rna-dependent rna polymerase (rdrp, p2) binds at sites inside the shell. p2 and p4 are present in substoichiometric amounts, raising the questions of whether they are recruited to the nascent procapsid in defined amounts and at specifi ... | 2010 | 20538059 |
| natural allelic variation underlying a major fitness trade-off in arabidopsis thaliana. | plants can defend themselves against a wide array of enemies, from microbes to large animals, yet there is great variability in the effectiveness of such defences, both within and between species. some of this variation can be explained by conflicting pressures from pathogens with different modes of attack. a second explanation comes from an evolutionary 'tug of war', in which pathogens adapt to evade detection, until the plant has evolved new recognition capabilities for pathogen invasion. if s ... | 2010 | 20520716 |
| mediation of the transition from biotrophy to necrotrophy in hemibiotrophic plant pathogens by secreted effector proteins. | hemibiotrophs, such as phytophthora infestans, exhibit distinct phases of their life cycle: an early asymptomatic biotrophic phase and a late necrotrophic stage that is characterized by tissue degradation and disease symptoms. to date, little is known of the molecular mechanisms that promote each distinct phase, nor those that mediate the transition between the two. we hypothesized that these phytopathogens might secrete distinct classes of effector proteins that first suppress plant defense res ... | 2010 | 20400849 |
| nonhost resistance to magnaporthe oryzae in arabidopsis thaliana. | rice blast, caused by magnaporthe oryzae, is a devastating disease of rice (oryza sativa). the mechanisms involved in resistance of rice to blast have been studied extensively and the rice--m. oryzae pathosystem has become a model for plant--microbe interaction studies. however, the mechanisms involved in nonhost resistance (nhr) of other plants to rice blast are still poorly understood. we have recently demonstrated that agb1 and pmr5 contribute to pen2-mediated preinvasion resistance to m. ory ... | 2010 | 20404515 |
| physiological regulation and functional significance of shade avoidance responses to neighbors. | plants growing in dense vegetations compete with their neighbors for resources such as water, nutrients and light. the competition for light has been particularly well studied, both for its fitness consequences as well as the adaptive behaviors that plants display to win the battle for light interception. aboveground, plants detect their competitors through photosensory cues, notably the red:far-red light ratio (r:fr). the r:fr is a very reliable indicator of future competition as it decreases i ... | 2010 | 20404496 |
| defensin-like zmes4 mediates pollen tube burst in maize via opening of the potassium channel kzm1. | in contrast to animals and lower plant species, sperm cells of flowering plants are non-motile and are transported to the female gametes via the pollen tube, i.e. the male gametophyte. upon arrival at the female gametophyte two sperm cells are discharged into the receptive synergid cell to execute double fertilization. the first players involved in inter-gametophyte signaling to attract pollen tubes and to arrest their growth have been recently identified. in contrast the physiological mechanism ... | 2010 | 20532241 |
| activation of plant immune responses by a gain-of-function mutation in an atypical receptor-like kinase. | arabidopsis (arabidopsis thaliana) suppressor of npr1-1, constitutive1 (snc1) contains a gain-of-function mutation in a toll/interleukin receptor-nucleotide binding site-leucine-rich repeat resistance (r) protein and it has been a useful tool for dissecting r-protein-mediated immunity. here we report the identification and characterization of snc4-1d, a semidominant mutant with snc1-like phenotypes. snc4-1d constitutively expresses defense marker genes pr1, pr2, and pdf1.2, and displays enhanced ... | 2010 | 20508139 |
| transcriptional regulation of the crk/duf26 group of receptor-like protein kinases by ozone and plant hormones in arabidopsis. | plant receptor-like/pelle kinases (rlk) are a group of conserved signalling components that regulate developmental programs and responses to biotic and abiotic stresses. one of the largest rlk groups is formed by the domain of unknown function 26 (duf26) rlks, also called cysteine-rich receptor-like kinases (crks), which have been suggested to play important roles in the regulation of pathogen defence and programmed cell death. despite the vast number of rlks present in plants, however, only a f ... | 2010 | 20500828 |
| arabidopsis glutathione reductase1 plays a crucial role in leaf responses to intracellular hydrogen peroxide and in ensuring appropriate gene expression through both salicylic acid and jasmonic acid signaling pathways. | glutathione is a major cellular thiol that is maintained in the reduced state by glutathione reductase (gr), which is encoded by two genes in arabidopsis (arabidopsis thaliana; gr1 and gr2). this study addressed the role of gr1 in hydrogen peroxide (h(2)o(2)) responses through a combined genetic, transcriptomic, and redox profiling approach. to identify the potential role of changes in glutathione status in h(2)o(2) signaling, gr1 mutants, which show a constitutive increase in oxidized glutathio ... | 2010 | 20488891 |
| the biosynthetic pathways for shikimate and aromatic amino acids in arabidopsis thaliana. | the aromatic amino acids phenylalanine, tyrosine and tryptophan in plants are not only essential components of protein synthesis, but also serve as precursors for a wide range of secondary metabolites that are important for plant growth as well as for human nutrition and health. the aromatic amino acids are synthesized via the shikimate pathway followed by the branched aromatic amino acid metabolic pathway, with chorismate serving as a major branch point intermediate metabolite. yet, the regulat ... | 2010 | 22303258 |
| from perception to activation: the molecular-genetic and biochemical landscape of disease resistance signaling in plants. | more than 60 years ago, h.h. flor proposed the "gene-for-gene" hypothesis, which described the genetic relationship between host plants and pathogens. in the decades that followed flor's seminal work, our understanding of the plant-pathogen interaction has evolved into a sophisticated model, detailing the molecular genetic and biochemical processes that control host-range, disease resistance signaling and susceptibility. the interaction between plants and microbes is an intimate exchange of sign ... | 2010 | 22303251 |
| variation of herbivore-induced volatile terpenes among arabidopsis ecotypes depends on allelic differences and subcellular targeting of two terpene synthases, tps02 and tps03. | when attacked by insects, plants release mixtures of volatile compounds that are beneficial for direct or indirect defense. natural variation of volatile emissions frequently occurs between and within plant species, but knowledge of the underlying molecular mechanisms is limited. we investigated intraspecific differences of volatile emissions induced from rosette leaves of 27 accessions of arabidopsis (arabidopsis thaliana) upon treatment with coronalon, a jasmonate mimic eliciting responses sim ... | 2010 | 20463089 |
| phytophthora infestans effector avr3a is essential for virulence and manipulates plant immunity by stabilizing host e3 ligase cmpg1. | fungal and oomycete plant pathogens translocate effector proteins into host cells to establish infection. however, virulence targets and modes of action of their effectors are unknown. effector avr3a from potato blight pathogen phytophthora infestans is translocated into host cells and occurs in two forms: avr3a(ki), which is detected by potato resistance protein r3a, strongly suppresses infestin 1 (inf1)-triggered cell death (icd), whereas avr3a(em), which evades recognition by r3a, weakly supp ... | 2010 | 20457921 |
| glutathione transferases. | the 55 arabidopsis glutathione transferases (gsts) are, with one microsomal exception, a monophyletic group of soluble enzymes that can be divided into phi, tau, theta, zeta, lambda, dehydroascorbate reductase (dhar) and tchqd classes. the populous phi and tau classes are often highly stress inducible and regularly crop up in proteomic and transcriptomic studies. despite much study on their xenobiotic-detoxifying activities their natural roles are unclear, although roles in defence-related secon ... | 2010 | 22303257 |
| regulation of the expression of plant resistance gene snc1 by a protein with a conserved bat2 domain. | plant resistance (r) genes encode immune receptors that recognize pathogens and activate defense responses. because of fitness costs associated with maintaining r protein-mediated resistance, expression levels of r genes have to be tightly regulated. however, mechanisms on how r-gene expression is regulated are poorly understood. here we show that modifier of snc1, 1 (mos1) regulates the expression of suppressor of npr1-1, constitutive1 (snc1), which encodes a toll/interleukin receptor-nucleotid ... | 2010 | 20439546 |
| phosphorylation of receptor-like cytoplasmic kinases by bacterial flagellin. | molecular mechanisms that distinguish self and non-self are fundamental in innate immunity to prevent infections in plants and animals. recognition of the conserved microbial components triggers immune responses against a broad spectrum of potential pathogens. in arabidopsis, bacterial flagellin was perceived by a leucine-rich repeat-receptor-like kinase (lrr-rlk) fls2. upon flagellin perception, fls2 forms a complex with another lrr-rlk bak1. the intracellular signaling events downstream of fls ... | 2010 | 20404519 |
| jasmonate and phytochrome a signaling in arabidopsis wound and shade responses are integrated through jaz1 stability. | jasmonate (ja) activates plant defense, promotes pollen maturation, and suppresses plant growth. an emerging theme in ja biology is its involvement in light responses; here, we examine the interdependence of the ja- and light-signaling pathways in arabidopsis thaliana. we demonstrate that mutants deficient in ja biosynthesis and signaling are deficient in a subset of high irradiance responses in far-red (fr) light. these mutants display exaggerated shade responses to low, but not high, r/fr rati ... | 2010 | 20435902 |
| changes in external ph rapidly alter plant gene expression and modulate auxin and elicitor responses. | ph is a highly variable environmental factor for the root, and plant cells can modify apoplastic ph for nutrient acquisition and in response to extracellular signals. nevertheless, surprisingly few effects of external ph on plant gene expression have been reported. we have used microarrays to investigate whether external ph affects global gene expression. in arabidopsis thaliana roots, 881 genes displayed at least twofold changes in transcript abundance 8 h after shifting medium ph from 6.0 to 4 ... | 2010 | 20444216 |
| information processing without brains--the power of intercellular regulators in plants. | plants exhibit different developmental strategies than animals; these are characterized by a tight linkage between environmental conditions and development. as plants have neither specialized sensory organs nor a nervous system, intercellular regulators are essential for their development. recently, major advances have been made in understanding how intercellular regulation is achieved in plants on a molecular level. plants use a variety of molecules for intercellular regulation: hormones are us ... | 2010 | 20332147 |
| the genuine ligand of a jasmonic acid receptor: improved analysis of jasmonates is now required. | jasmonic acid (ja), its metabolites, such as the methyl ester or amino acid conjugates as well as its precursor 12-oxophytodienoic acid (opda) are lipid-derived signals. ja, opda and ja-amino acid conjugates are known to function as signals in plant stress responses and development. more recently, formation of ja-amino acid conjugates and high biological activity of ja-isoleucine (ja-ile) were found to be essential in ja signaling. a breakthrough was the identification of jaz proteins which inte ... | 2010 | 20404483 |
| auto-luminescent genetically-encoded ratiometric indicator for real-time ca2+ imaging at the single cell level. | efficient bioluminescence resonance energy transfer (bret) from a bioluminescent protein to a fluorescent protein with high fluorescent quantum yield has been utilized to enhance luminescence intensity, allowing single-cell imaging in near real time without external light illumination. | 2010 | 20376337 |
| calcium signals: the lead currency of plant information processing. | ca(2+) signals are core transducers and regulators in many adaptation and developmental processes of plants. ca(2+) signals are represented by stimulus-specific signatures that result from the concerted action of channels, pumps, and carriers that shape temporally and spatially defined ca(2+) elevations. cellular ca(2+) signals are decoded and transmitted by a toolkit of ca(2+) binding proteins that relay this information into downstream responses. major transduction routes of ca(2+) signaling i ... | 2010 | 20354197 |
| large-scale analysis of full-length cdnas from the tomato (solanum lycopersicum) cultivar micro-tom, a reference system for the solanaceae genomics. | the solanaceae family includes several economically important vegetable crops. the tomato (solanum lycopersicum) is regarded as a model plant of the solanaceae family. recently, a number of tomato resources have been developed in parallel with the ongoing tomato genome sequencing project. in particular, a miniature cultivar, micro-tom, is regarded as a model system in tomato genomics, and a number of genomics resources in the micro-tom-background, such as ests and mutagenized lines, have been es ... | 2010 | 20350329 |
| transcriptional profiling of an fd-gogat1/glu1 mutant in arabidopsis thaliana reveals a multiple stress response and extensive reprogramming of the transcriptome. | glutamate plays a central position in the synthesis of a variety of organic molecules in plants and is synthesised from nitrate through a series of enzymatic reactions. glutamate synthases catalyse the last step in this pathway and two types are present in plants: nadh- or ferredoxin-dependent. here we report a genome wide microarray analysis of the transcriptional reprogramming that occurs in leaves and roots of the a. thaliana mutant glu1-2 knocked-down in the expression of fd-gogat1 (glu1; at ... | 2010 | 20307264 |
| the rst and parp-like domain containing sro protein family: analysis of protein structure, function and conservation in land plants. | the sros (similar to rcd-one) are a group of plant-specific proteins which have important functions in stress adaptation and development. they contain the catalytic core of the poly(adp-ribose) polymerase (parp) domain and a c-terminal rst (rcd-sro-taf4) domain. in addition to these domains, several, but not all, sros contain an n-terminal wwe domain. | 2010 | 20226034 |
| assembly algorithms for next-generation sequencing data. | the emergence of next-generation sequencing platforms led to resurgence of research in whole-genome shotgun assembly algorithms and software. dna sequencing data from the roche 454, illumina/solexa, and abi solid platforms typically present shorter read lengths, higher coverage, and different error profiles compared with sanger sequencing data. since 2005, several assembly software packages have been created or revised specifically for de novo assembly of next-generation sequencing data. this re ... | 2010 | 20211242 |
| natural products version 2.0: connecting genes to molecules. | natural products have played a prominent role in the history of organic chemistry, and they continue to be important as drugs, biological probes, and targets of study for synthetic and analytical chemists. in this perspective, we explore how connecting nature's small molecules to the genes that encode them has sparked a renaissance in natural product research, focusing primarily on the biosynthesis of polyketides and non-ribosomal peptides. we survey monomer biogenesis, coupling chemistries from ... | 2010 | 20121095 |
| control of colletotrichum gloeosporioides (penz.) sacc. in yellow passion fruit using cymbopogon citratus essential oil. | the use of antibiotics in agriculture is limited when compared to their applications in human and veterinary medicine. on the other hand, the use of antimicrobials in agriculture contributes to the drug resistance of human pathogens and has stimulated the search for new antibiotics from natural products. essential oils have been shown to exert several biological activities including antibacterial and antifungal actions. the aim of this study was to determine the activity of 28 essential oils fro ... | 2010 | 24031465 |
| bacterial effectors target bak1-associated receptor complexes: one stone two birds. | the long-standing association between hosts and microbes has generated some of most intricate relationships. the studies on molecular mechanisms of host-microbe interaction have been revealing many fascinating stories. here we zoom in on a specific topic on the interplay between bacterial effectors and plant innate immune signaling. in particular, we will summarize our recent discovery that bacterial effector proteins, avrpto and avrptob, target plant immune signaling receptor complexes to inter ... | 2010 | 20585495 |
| the lesion-mimic mutant cpr22 shows alterations in abscisic acid signaling and abscisic acid insensitivity in a salicylic acid-dependent manner. | a number of arabidopsis (arabidopsis thaliana) lesion-mimic mutants exhibit alterations in both abiotic stress responses and pathogen resistance. one of these mutants, constitutive expresser of pr genes22 (cpr22), which has a mutation in two cyclic nucleotide-gated ion channels, is a typical lesion-mimic mutant exhibiting elevated levels of salicylic acid (sa), spontaneous cell death, constitutive expression of defense-related genes, and enhanced resistance to various pathogens; the majority of ... | 2010 | 20164209 |