| cell wall integrity: targeted post-synthetic modifications to reveal its role in plant growth and defense against pathogens. | the plant cell wall, a dynamic network of polysaccharides and glycoproteins of significant compositional and structural complexity, functions in plant growth, development and stress responses. in recent years, the existence of plant cell wall integrity (cwi) maintenance mechanisms has been demonstrated, but little is known about the signaling pathways involved, or their components. examination of key mutants has shed light on the relationships between cell wall remodeling and plant cell response ... | 2013 | 23857352 |
| draft genome sequence of the antarctic psychrophilic bacterium pseudomonas syringae strain lz4w. | the psychrophilic bacterium pseudomonas syringae strain lz4w was isolated from soil samples from antarctica to decipher the mechanisms of low-temperature adaptation. we report here the 4.982-mb draft genome sequence of p. syringae lz4w. this sequence will provide insights into the genomic basis of the psychrophilicity of this bacterium. | 2013 | 23788547 |
| powdery mildew resistance in tomato by impairment of slpmr4 and sldmr1. | genetic dissection of disease susceptibility in arabidopsis to powdery and downy mildew has identified multiple susceptibility (s) genes whose impairment results in disease resistance. although several of these s-genes have been cloned and characterized in more detail it is unknown to which degree their function in disease susceptibility is conserved among different plant species. moreover, it is unclear whether impairment of such genes has potential in disease resistance breeding due to possibl ... | 2013 | 23818978 |
| an extracellular subtilase switch for immune priming in arabidopsis. | in higher eukaryotes, induced resistance associates with acquisition of a priming state of the cells for a more effective activation of innate immunity; however, the nature of the components for mounting this type of immunological memory is not well known. we identified an extracellular subtilase from arabidopsis, sbt3.3, the overexpression of which enhances innate immune responses while the loss of function compromises them. sbt3.3 expression initiates a durable autoinduction mechanism that pro ... | 2013 | 23818851 |
| the herbivore elicitor-regulated1 gene enhances abscisic acid levels and defenses against herbivores in nicotiana attenuata plants. | nicotiana attenuata plants can distinguish the damage caused by herbivore feeding from other types of damage by perceiving herbivore-associated elicitors, such as the fatty acid-amino acid conjugates (facs) in oral secretions (os) of manduca sexta larvae, which are introduced into wounds during feeding. however, the transduction of fac signals into downstream plant defense responses is still not well established. we identified a novel fac-regulated protein in n. attenuata (naher1; for herbivore ... | 2013 | 23784463 |
| pepper arginine decarboxylase is required for polyamine and γ-aminobutyric acid signaling in cell death and defense response. | the xanthomonas campestris pv vesicatoria (xcv) effector avrbst induces a hypersensitive cell death in pepper (capsicum annuum). however, the molecular mechanisms underlying avrbst-triggered cell death are not fully understood. here, we identified pepper arginine decarboxylase (caadc1) as an avrbst-interacting protein, which is early and strongly induced in incompatible pepper-xcv interactions. bimolecular fluorescence complementation and coimmunoprecipitation assays showed that the caadc1-avrbs ... | 2013 | 23784462 |
| transient transcriptional regulation of the cys-c1 gene and cyanide accumulation upon pathogen infection in the plant immune response. | cyanide is produced concomitantly with ethylene biosynthesis. arabidopsis (arabidopsis thaliana) detoxifies cyanide primarily through the enzyme β-cyanoalanine synthase, mainly by the mitochondrial cys-c1. cys-c1 loss of function is not toxic for the plant and leads to an increased level of cyanide in cys-c1 mutants as well as a root hairless phenotype. the classification of genes differentially expressed in cys-c1 and wild-type plants reveals that the high endogenous cyanide content of the cys- ... | 2013 | 23784464 |
| study on citrus response to huanglongbing highlights a down-regulation of defense-related proteins in lemon plants upon 'ca. liberibacter asiaticus' infection. | citrus huanglongbing (hlb) is a highly destructive disease of citrus presumably caused by 'candidatus liberibacterasiaticus' (las), a gram-negative, insect-transmitted, phloem-limited α-proteobacterium. although almost all citrus plants are susceptible to hlb, reports have shown reduced susceptibility to las infection in lemon (citrus limon) plants. the aim of this study is to identify intra-species specific molecular mechanisms associated with las-induced responses in lemon plants. to achieve t ... | 2013 | 23922636 |
| a low temperature limit for life on earth. | there is no generally accepted value for the lower temperature limit for life on earth. we present empirical evidence that free-living microbial cells cooling in the presence of external ice will undergo freeze-induced desiccation and a glass transition (vitrification) at a temperature between -10°c and -26°c. in contrast to intracellular freezing, vitrification does not result in death and cells may survive very low temperatures once vitrified. the high internal viscosity following vitrificatio ... | 2013 | 23840425 |
| regulation of astrocyte glutamine synthetase in epilepsy. | astrocytes play a crucial role in regulating and maintaining the extracellular chemical milieu of the central nervous system under physiological conditions. moreover, proliferation of phenotypically altered astrocytes (a.k.a. reactive astrogliosis) has been associated with many neurologic and psychiatric disorders, including mesial temporal lobe epilepsy (mtle). glutamine synthetase (gs), which is found in astrocytes, is the only enzyme known to date that is capable of converting glutamate and a ... | 2013 | 23791709 |
| the acute transcriptional response of the coral acropora millepora to immune challenge: expression of gimap/ian genes links the innate immune responses of corals with those of mammals and plants. | as a step towards understanding coral immunity we present the first whole transcriptome analysis of the acute responses of acropora millepora to challenge with the bacterial cell wall derivative mdp and the viral mimic poly i:c, defined immunogens provoking distinct but well characterised responses in higher animals. | 2013 | 23768317 |
| metabolomic-based study of the leafy gall, the ecological niche of the phytopathogen rhodococcus fascians, as a potential source of bioactive compounds. | leafy gall is a plant hyperplasia induced upon rhodococcus fascians infection. previously, by genomic and transcriptomic analysis, it has been reported that, at the early stage of symptom development, both primary and secondary metabolisms are modified. the present study is based on the hypothesis that fully developed leafy gall, could represent a potential source of new bioactive compounds. therefore, non-targeted metabolomic analysis of aqueous and chloroform extracts of leafy gall and non-inf ... | 2013 | 23771021 |
| release of proteins from intact chloroplasts induced by reactive oxygen species during biotic and abiotic stress. | plastids sustain life on this planet by providing food, feed, essential biomolecules and oxygen. such diverse metabolic and biosynthetic functions require efficient communication between plastids and the nucleus. however, specific factors, especially large molecules, released from plastids that regulate nuclear genes have not yet been fully elucidated. when tobacco and lettuce transplastomic plants expressing gfp within chloroplasts, were challenged with erwinia carotovora (biotic stress) or par ... | 2013 | 23799142 |
| export of salicylic acid from the chloroplast requires the multidrug and toxin extrusion-like transporter eds5. | salicylic acid (sa) is central for the defense of plants to pathogens and abiotic stress. sa is synthesized in chloroplasts from chorismic acid by an isochorismate synthase (ics1); sa biosynthesis is negatively regulated by autoinhibitory feedback at ics1. genetic studies indicated that the multidrug and toxin extrusion transporter enhanced disease susceptibility5 (eds5) of arabidopsis (arabidopsis thaliana) is necessary for sa accumulation after biotic and abiotic stress, but so far it is not u ... | 2013 | 23757404 |
| high throughput quantitative phenotyping of plant resistance using chlorophyll fluorescence image analysis. | in order to select for quantitative plant resistance to pathogens, high throughput approaches that can precisely quantify disease severity are needed. automation and use of calibrated image analysis should provide more accurate, objective and faster analyses than visual assessments. in contrast to conventional visible imaging, chlorophyll fluorescence imaging is not sensitive to environmental light variations and provides single-channel images prone to a segmentation analysis by simple threshold ... | 2013 | 23758798 |
| identification and analysis of mkk and mpk gene families in canola (brassica napus l.). | eukaryotic mitogen-activated protein kinase (mapk/mpk) signaling cascades transduce and amplify environmental signals via three types of reversibly phosphorylated kinases to activate defense gene expression. canola (oilseed rape, brassica napus) is a major crop in temperate regions. identification and characterization of mapk and mapk kinases (mapkk/mkk) of canola will help to elucidate their role in responses to abiotic and biotic stresses. | 2013 | 23758924 |
| inferring ancient metabolism using ancestral core metabolic models of enterobacteria. | enterobacteriaceae diversified from an ancestral lineage ~300-500 million years ago (mya) into a wide variety of free-living and host-associated lifestyles. nutrient availability varies across niches, and evolution of metabolic networks likely played a key role in adaptation. | 2013 | 23758866 |
| genome-wide survey of cold stress regulated alternative splicing in arabidopsis thaliana with tiling microarray. | alternative splicing plays a major role in expanding the potential informational content of eukaryotic genomes. it is an important post-transcriptional regulatory mechanism that can increase protein diversity and affect mrna stability. alternative splicing is often regulated in a tissue-specific and stress-responsive manner. cold stress, which adversely affects plant growth and development, regulates the transcription and splicing of plant splicing factors. this can affect the pre-mrna processin ... | 2013 | 23776682 |
| simultaneous application of heat, drought, and virus to arabidopsis plants reveals significant shifts in signaling networks. | considering global climate change, the incidence of combined drought and heat stress is likely to increase in the future and will considerably influence plant-pathogen interactions. until now, little has been known about plants exposed to simultaneously occurring abiotic and biotic stresses. to shed some light on molecular plant responses to multiple stress factors, a versatile multifactorial test system, allowing simultaneous application of heat, drought, and virus stress, was developed in arab ... | 2013 | 23753177 |
| there's more to the picture than meets the eye: nitric oxide cross talk with ca2+ signaling. | calcium and nitric oxide (no) are two important biological messengers. increasing evidence indicates that ca(2+) and no work together in mediating responses to pathogenic microorganisms and microbe-associated molecular patterns. ca(2+) fluxes were recognized to account for no production, whereas evidence gathered from a number of studies highlights that no is one of the key messengers mediating ca(2+) signaling. here, we present a concise description of the current understanding of the molecular ... | 2013 | 23749853 |
| salicylic acid regulates plasmodesmata closure during innate immune responses in arabidopsis. | in plants, mounting an effective innate immune strategy against microbial pathogens involves triggering local cell death within infected cells as well as boosting the immunity of the uninfected neighboring and systemically located cells. although not much is known about this, it is evident that well-coordinated cell-cell signaling is critical in this process to confine infection to local tissue while allowing for the spread of systemic immune signals throughout the whole plant. in support of thi ... | 2013 | 23749844 |
| are we biologically safe with snow precipitation? a case study in beijing. | in this study, the bacterial and fungal abundances, diversities, conductance levels as well as total organic carbon (toc) were investigated in the snow samples collected from five different snow occurrences in beijing between january and march, 2010. the collected snow samples were melted and cultured at three different temperatures (4, 26 and 37°c). the culturable bacterial concentrations were manually counted and the resulting colony forming units (cfus) at 26°c were further studied using v3 r ... | 2013 | 23762327 |
| crosstalk between the circadian clock and innate immunity in arabidopsis. | the circadian clock integrates temporal information with environmental cues in regulating plant development and physiology. recently, the circadian clock has been shown to affect plant responses to biotic cues. to further examine this role of the circadian clock, we tested disease resistance in mutants disrupted in cca1 and lhy, which act synergistically to regulate clock activity. we found that cca1 and lhy mutants also synergistically affect basal and resistance gene-mediated defense against p ... | 2013 | 23754942 |
| multilocus variable-number-tandem-repeats analysis (mlva) distinguishes a clonal complex of clavibacter michiganensis subsp. michiganensis strains isolated from recent outbreaks of bacterial wilt and canker in belgium. | clavibacter michiganensis subsp. michiganensis (cmm) causes bacterial wilt and canker in tomato. cmm is present nearly in all european countries. during the last three years several local outbreaks were detected in belgium. the lack of a convenient high-resolution strain-typing method has hampered the study of the routes of transmission of cmm and epidemiology in tomato cultivation. in this study the genetic relatedness among a worldwide collection of cmm strains and their relatives was approach ... | 2013 | 23738754 |
| quantitative trait loci for partial resistance to pseudomonas syringae pv. maculicola in arabidopsis thaliana. | segregation of partial resistance to pseudomonas syringae pv. maculicola (psm) es4326 was studied in the recombinant inbred population created from accessions (ecotypes) columbia (col-4), the more susceptible parent, and landsberg (ler-0). plants were spray inoculated with lux-transformed bacteria in experiments to measure susceptibility. the amount of disease produced on a range of col × ler lines by spray inoculation was highly correlated with that produced by pressure infiltration of bacteria ... | 2013 | 23724899 |
| overexpression of a citrus ndr1 ortholog increases disease resistance in arabidopsis. | emerging devastating diseases, such as huanglongbing (hlb) and citrus canker, have caused tremendous losses to the citrus industry worldwide. genetic engineering is a powerful approach that could allow us to increase citrus resistance against these diseases. the key to the success of this approach relies on a thorough understanding of defense mechanisms of citrus. studies of arabidopsis and other plants have provided a framework for us to better understand defense mechanisms of citrus. salicylic ... | 2013 | 23761797 |
| induction of systemic resistance against cucumber mosaic virus in arabidopsis thaliana by trichoderma asperellum skt-1. | trichoderma asperellum skt-1 is a microbial pesticide that is very effective against various diseases. our study was undertaken to evaluate t. asperellum skt-1 for induction of resistance against yellow strain of cucumber mosaic virus (cmv-y) in arabidopsis plants. disease severity was rated at 2 weeks post inoculation (wpi). cmv titre in arabidopsis leaves was determined by indirect enzyme-linked immunosorbent assay (elisa) at 2 wpi. our results demonstrated that among all arabidopsis plants tr ... | 2013 | 25288946 |
| determinants of plant growth-promoting ochrobactrum lupini kudc1013 involved in induction of systemic resistance against pectobacterium carotovorum subsp. carotovorum in tobacco leaves. | the plant growth-promoting rhizobacterium ochrobactrum lupini kudc1013 elicited induced systemic resistance (isr) in tobacco against soft rot disease caused by pectobacterium carotovorum subsp. carotovorum. we investigated of its factors involved in isr elicitation. to characterize the isr determinants, kudc1013 cell suspension, heat-treated cells, supernatant from a culture medium, crude bacterial lipopolysaccharide (lps) and flagella were tested for their isr activities. both lps and flagella ... | 2013 | 25288944 |
| transcriptome analysis of induced systemic drought tolerance elicited by pseudomonas chlororaphis o6 in arabidopsis thaliana. | root colonization by pseudomonas chlororaphis o6 induces systemic drought tolerance in arabidopsis thaliana. microarray analysis was performed using the 22,800-gene affymetrix genechips to identify differentially-expressed genes from plants colonized with or without p. chlororaphis o6 under drought stressed conditions or normal growth conditions. root colonization in plants grown under regular irrigation condition increased transcript accumulation from genes associated with defense, response to ... | 2013 | 25288948 |
| contribution of small rna pathway components in plant immunity. | small rnas regulate a multitude of cellular processes, including development, stress responses, metabolism, and maintenance of genome integrity, in a sequence-specific manner. accumulating evidence reveals that host endogenous small rnas and small rna pathway components play important roles in plant immune responses against various pathogens, including bacteria, fungi, oomycetes, and viruses. small-rna-mediated defense responses are regulated through diverse pathways and the components of these ... | 2013 | 23489060 |
| functional analysis of arabidopsis mutants points to novel roles for glutathione in coupling h(2)o(2) to activation of salicylic acid accumulation and signaling. | through its interaction with h(2)o(2), glutathione is a candidate for transmission of signals in plant responses to pathogens, but identification of signaling roles is complicated by its antioxidant function. using a genetic approach based on a conditional catalase-deficient arabidopsis mutant, cat2, this study aimed at establishing whether gsh plays an important functional role in the transmission of signals downstream of h(2)o(2). | 2013 | 23148658 |
| the floral transition is not the developmental switch that confers competence for the arabidopsis age-related resistance response to pseudomonas syringae pv. tomato. | age-related resistance (arr) is a plant defense response characterized by enhanced resistance to certain pathogens in mature plants relative to young plants. in arabidopsis thaliana the transition to flowering is associated with arr competence, suggesting that this developmental event is the switch that initiates arr competence in mature plants (rusterucci et al. in physiol mol plant pathol 66:222-231, 2005). the association of arr and the floral transition was examined using flowering-time muta ... | 2013 | 23722504 |
| battle through signaling between wheat and the fungal pathogen septoria tritici revealed by proteomics and phosphoproteomics. | the fungus septoria tritici causes the disease septoria tritici blotch in wheat, one of the most economically devastating foliar diseases in this crop. to investigate signaling events and defense responses in the wheat-s. tritici interaction, we performed a time-course study of s. tritici infection in resistant and susceptible wheat using quantitative proteomics and phosphoproteomics, with special emphasis on the initial biotrophic phase of interactions. our study revealed an accumulation of def ... | 2013 | 23722186 |
| silicon era of carbon-based life: application of genomics and bioinformatics in crop stress research. | abiotic and biotic stresses lead to massive reprogramming of different life processes and are the major limiting factors hampering crop productivity. omics-based research platforms allow for a holistic and comprehensive survey on crop stress responses and hence may bring forth better crop improvement strategies. since high-throughput approaches generate considerable amounts of data, bioinformatics tools will play an essential role in storing, retrieving, sharing, processing, and analyzing them. ... | 2013 | 23759993 |
| system-wide hypersensitive response-associated transcriptome and metabolome reprogramming in tomato. | the hypersensitive response (hr) is considered to be the hallmark of the resistance response of plants to pathogens. to study hr-associated transcriptome and metabolome reprogramming in tomato (solanum lycopersicum), we used plants that express both a resistance gene to cladosporium fulvum and the matching avirulence gene of this pathogen. in these plants, massive reprogramming occurred, and we found that the hr and associated processes are highly energy demanding. ubiquitin-dependent protein de ... | 2013 | 23719893 |
| proteomic survey of the streptomyces coelicolor nucleoid. | nucleoid-associated proteins (naps) are small, highly abundant transcriptional regulators with low sequence specificity which are involved in multiple dna-related processes including gene expression, dna protection, recombination/repair and nucleoid structuring. through these functions they are able to regulate important phenotypic properties including virulence, secondary metabolism and stress resistance. however the set of naps known within the actinobacteria is small and incomplete. the missi ... | 2013 | 23523638 |
| enzyme action in the regulation of plant hormone responses. | plants synthesize a chemically diverse range of hormones that regulate growth, development, and responses to environmental stresses. the major classes of plant hormones are specialized metabolites with exquisitely tailored perception and signaling systems, but equally important are the enzymes that control the dose and exposure to the bioactive forms of these molecules. here, we review new insights into the role of enzyme families, including the sabath methyltransferases, the methylesterases, th ... | 2013 | 23709222 |
| comprehensive investigation of micrornas enhanced by analysis of sequence variants, expression patterns, argonaute loading, and target cleavage. | micrornas (mirnas) are a class of small rnas that typically function by guiding the cleavage of target messenger rnas. they have been shown to play major roles in a variety of plant processes, including development, and responses to pathogens and environmental stresses. to identify new mirnas and regulation in arabidopsis (arabidopsis thaliana), 27 small rna libraries were constructed and sequenced from various tissues, stresses, and small rna biogenesis mutants, resulting in 95 million genome-m ... | 2013 | 23709668 |
| exo70a1-mediated vesicle trafficking is critical for tracheary element development in arabidopsis. | exocysts are highly conserved octameric complexes that play an essential role in the tethering of golgi-derived vesicles to target membranes in eukaryotic organisms. genes encoding the exo70 subunit are highly duplicated in plants. based on expression analyses, we proposed previously that individual exo70 members may provide the exocyst with functional specificity to regulate cell type- or cargo-specific exocytosis, although direct evidence is not available. here, we show that, as a gene express ... | 2013 | 23709627 |
| plant immune responses against viruses: how does a virus cause disease? | plants respond to pathogens using elaborate networks of genetic interactions. recently, significant progress has been made in understanding rna silencing and how viruses counter this apparently ubiquitous antiviral defense. in addition, plants also induce hypersensitive and systemic acquired resistance responses, which together limit the virus to infected cells and impart resistance to the noninfected tissues. molecular processes such as the ubiquitin proteasome system and dna methylation are al ... | 2013 | 23709626 |
| members of the xb3 family from diverse plant species induce programmed cell death in nicotiana benthamiana. | programmed cell death has been associated with plant immunity and senescence. the receptor kinase xa21 confers resistance to bacterial blight disease of rice (oryza sativa) caused by xanthomonas oryzae pv. oryzae (xoo). here we show that the xa21 binding protein 3 (xb3) is capable of inducing cell death when overexpressed in nicotiana benthamiana. xb3 is a ring finger-containing e3 ubiquitin ligase that has been positively implicated in xa21-mediated resistance. mutation abolishing the xb3 e3 ac ... | 2013 | 23717500 |
| fatty acid-and retinol-binding protein, mj-far-1 induces tomato host susceptibility to root-knot nematodes. | plant-parasitic nematodes produce at least one structurally unique class of small helix-rich retinol- and fatty-acid-binding proteins that have no counterparts in their plant hosts. herein we describe a protein of the plant-parasitic root-knot nematode meloidogyne javanica, which is a member of the nematode-specific fatty-acid- and retinol-binding (mj-far-1) family of proteins. the mj-far-1 mrna was detected through m. javanica pre-parasitic j2s, migratory and sedentary parasitic stages by quant ... | 2013 | 23717636 |
| jasmonates trigger prey-induced formation of 'outer stomach' in carnivorous sundew plants. | it has been widely accepted that the growth-related phytohormone auxin is the endogenous signal that initiates bending movements of plant organs. in 1875, charles darwin described how the bending movement of leaves in carnivorous sundew species formed an 'outer stomach' that allowed the plants to enclose and digest captured insect prey. about 100 years later, auxin was suggested to be the factor responsible for this movement. we report that prey capture induces both leaf bending and the accumula ... | 2013 | 23516244 |
| deletion of a tandem gene family in arabidopsis: increased mekk2 abundance triggers autoimmunity when the mekk1-mkk1/2-mpk4 signaling cascade is disrupted. | an arabidopsis thaliana mitogen-activated protein (map) kinase cascade composed of mekk1, mkk1/mkk2, and mpk4 was previously described as a negative regulator of defense response. mekk1 encodes a map kinase kinase kinase and is a member of a tandemly duplicated gene family with mekk2 and mekk3. using t-dna insertion lines, we isolated a novel deletion mutant disrupting this gene family and found it to be phenotypically wild-type, in contrast with the mekk1 dwarf phenotype. follow-up genetic anal ... | 2013 | 23695980 |
| bsk1, a receptor-like cytoplasmic kinase, involved in both br signaling and innate immunity in arabidopsis. | molecular interaction between powdery mildew fungi and arabidopsis has been widely used as a model system to study plant immunity. arabidopsis edr2 (enhanced disease resistance 2) is a well characterized negative regulator in powdery mildew resistance and mildew-induced cell death. recently, we showed that a mutation in bsk1 (br-signaling kinase 1), suppressed edr2-mediated disease resistance. (1) and the bsk1-1 single mutant displayed enhanced susceptibility to multiple pathogens, indicating th ... | 2013 | 23733062 |
| regulation of transcription of nucleotide-binding leucine-rich repeat-encoding genes snc1 and rpp4 via h3k4 trimethylation. | plant nucleotide-binding leucine-rich repeat (nb-lrr) proteins serve as intracellular sensors to detect pathogen effectors and trigger immune responses. transcription of the nb-lrr-encoding resistance (r) genes needs to be tightly controlled to avoid inappropriate defense activation. how the expression of the nb-lrr r genes is regulated is poorly understood. the arabidopsis (arabidopsis thaliana) suppressor of npr1-1, constitutive 1 (snc1) mutant carries a gain-of-function mutation in a toll/int ... | 2013 | 23690534 |
| root exudates from grafted-root watermelon showed a certain contribution in inhibiting fusarium oxysporum f. sp. niveum. | grafting watermelon onto bottle gourd rootstock is commonly used method to generate resistance to fusarium oxysporum f. sp. niveum (fon), but knowledge of the effect of the root exudates of grafted watermelon on this soil-borne pathogen in rhizosphere remains limited. to investigate the root exudate profiles of the own-root bottle gourd, grafted-root watermelon and own-root watermelon, recirculating hydroponic culture system was developed to continuously trap these root exudates. both conidial g ... | 2013 | 23700421 |
| introns of plant pri-mirnas enhance mirna biogenesis. | plant mir genes are independent transcription units that encode long primary mirna precursors, which usually contain introns. for two mirna genes, mir163 and mir161, we show that introns are crucial for the accumulation of proper levels of mature mirna. removal of the intron in both cases led to a drop-off in the level of mature mirnas. we demonstrate that the stimulating effects of the intron mostly reside in the 5'ss rather than on a genuine splicing event. our findings are biologically signif ... | 2013 | 23681439 |
| plant defense against insect herbivores. | plants have been interacting with insects for several hundred million years, leading to complex defense approaches against various insect feeding strategies. some defenses are constitutive while others are induced, although the insecticidal defense compound or protein classes are often similar. insect herbivory induce several internal signals from the wounded tissues, including calcium ion fluxes, phosphorylation cascades and systemic- and jasmonate signaling. these are perceived in undamaged ti ... | 2013 | 23681010 |
| multiple classes of immune-related proteases associated with the cell death response in pepper plants. | proteases regulate a large number of biological processes in plants, such as metabolism, physiology, growth, and defense. in this study, we carried out virus-induced gene silencing assays with pepper cdna clones to elucidate the biological roles of protease superfamilies. a total of 153 representative protease genes from pepper cdna were selected and cloned into a tobacco rattle virus-ligation independent cloning vector in a loss-of-function study. silencing of 61 proteases resulted in altered p ... | 2013 | 23696830 |
| nicotiana attenuata mpk4 suppresses a novel jasmonic acid (ja) signaling-independent defense pathway against the specialist insect manduca sexta, but is not required for the resistance to the generalist spodoptera littoralis. | how plants tailor their defense responses to attack from different insects remains largely unknown. here, we studied the role of a mitogen-activated protein kinase (mapk), mpk4, in the resistance of a wild tobacco nicotiana attenuata to two herbivores, the specialist manduca sexta and the generalist spodoptera littoralis. stably transformed n. attenuata plants silenced in mpk4 (irmpk4) were generated and characterized for traits important for defense against herbivores. only the oral secretions ... | 2013 | 23672856 |
| lym2-dependent chitin perception limits molecular flux via plasmodesmata. | chitin acts as a pathogen-associated molecular pattern from fungal pathogens whose perception triggers a range of defense responses. we show that lysin motif domain-containing glycosylphosphatidylinositol-anchored protein 2 (lym2), the arabidopsis homolog of a rice chitin receptor-like protein, mediates a reduction in molecular flux via plasmodesmata in the presence of chitin. for this response, lym2-1 mutants are insensitive to the presence of chitin, but not to the flagellin derivative flg22. ... | 2013 | 23674687 |
| the cell morphogenesis angustifolia (an) gene, a plant homolog of ctbp/bars, is involved in abiotic and biotic stress response in higher plants. | angustifolia (an), one of the ctbp family proteins, plays a major role in microtubule-dependent cell morphogenesis. microarray analysis of mammalian an homologs suggests that an might function as a transcriptional activator and regulator of a wide range of genes. genetic characterization of an mutants suggests that an might be involved in multiple biological processes beyond cell morphology regulation. | 2013 | 23672620 |
| nitric oxide-based protein modification: formation and site-specificity of protein s-nitrosylation. | nitric oxide (no) is a reactive free radical with pleiotropic functions that participates in diverse biological processes in plants, such as germination, root development, stomatal closing, abiotic stress, and defense responses. it acts mainly through redox-based modification of cysteine residue(s) of target proteins, called protein s-nitrosylation.in this way no regulates numerous cellular functions and signaling events in plants. identification of s-nitrosylated substrates and their exact targ ... | 2013 | 23717319 |
| the moss physcomitrella patens reproductive organ development is highly organized, affected by the two shi/sty genes and by the level of active auxin in the shi/sty expression domain. | in order to establish a reference for analysis of the function of auxin and the auxin biosynthesis regulators short internode/stylish (shi/sty) during physcomitrella patens reproductive development, we have described male (antheridial) and female(archegonial) development in detail, including temporal and positional information of organ initiation. this has allowed us to define discrete stages of organ morphogenesis and to show that reproductive organ development in p. patens is highly organized ... | 2013 | 23669745 |
| cyclophilin 20-3 relays a 12-oxo-phytodienoic acid signal during stress responsive regulation of cellular redox homeostasis. | the jasmonate family of phytohormones plays central roles in plant development and stress acclimation. however, the architecture of their signaling circuits remains largely unknown. here we describe a jasmonate family binding protein, cyclophilin 20-3 (cyp20-3), which regulates stress-responsive cellular redox homeostasis. (+)-12-oxo-phytodienoic acid (opda) binding promotes cyp20-3 to form a complex with serine acetyltransferase 1, which triggers the formation of a hetero-oligomeric cysteine sy ... | 2013 | 23671085 |
| structural determinants at the interface of the arc2 and leucine-rich repeat domains control the activation of the plant immune receptors rx1 and gpa2. | many plant and animal immune receptors have a modular nucleotide-binding-leucine-rich repeat (nb-lrr) architecture in which a nucleotide-binding switch domain, nb-arc, is tethered to a lrr sensor domain. the cooperation between the switch and sensor domains, which regulates the activation of these proteins, is poorly understood. here, we report structural determinants governing the interaction between the nb-arc and lrr in the highly homologous plant immune receptors gpa2 and rx1, which recogniz ... | 2013 | 23660837 |
| requirement of vesicle-associated membrane protein 721 and 722 for sustained growth during immune responses in arabidopsis. | extracellular immune responses to ascomycete and oomycete pathogens in arabidopsis are dependent on vesicle-associated secretion mediated by the snare proteins pen1 syntaxin, snap33 and endomembrane-resident vamp721/722. continuous movement of functional gfp-vamp722 to and from the plasma membrane in non-stimulated cells reflects the second proposed function of vamp721/722 in constitutive secretion during plant growth and development. application of the bacterium-derived elicitor flg22 stabilize ... | 2013 | 23661365 |
| glutamate receptor-like channel3.3 is involved in mediating glutathione-triggered cytosolic calcium transients, transcriptional changes, and innate immunity responses in arabidopsis. | the tripeptide reduced glutathione (gsh; γ-glutamate [glu]-cysteine [cys]-glycine) is a major endogenous antioxidant in both animal and plant cells. it also functions as a neurotransmitter mediating communication among neurons in the central nervous system of animals through modulating specific ionotropic glu receptors (glrs) in the membrane. little is known about such signaling roles in plant cells. here, we report that transient rises in cytosolic calcium triggered by exogenous gsh in arabidop ... | 2013 | 23656893 |
| two volatile organic compounds trigger plant self-defense against a bacterial pathogen and a sucking insect in cucumber under open field conditions. | systemic acquired resistance (sar) is a plant self-defense mechanism against a broad-range of pathogens and insect pests. among chemical sar triggers, plant and bacterial volatiles are promising candidates for use in pest management, as these volatiles are highly effective, inexpensive, and can be employed at relatively low concentrations compared with agrochemicals. however, such volatiles have some drawbacks, including the high evaporation rate of these compounds after application in the open ... | 2013 | 23698768 |
| identification of ta-sirnas and cis-nat-sirnas in cassava and their roles in response to cassava bacterial blight. | trans-acting small interfering rnas (ta-sirnas) and natural cis-antisense sirnas (cis-nat-sirnas) are recently discovered small rnas (srnas) involved in post-transcriptional gene silencing. ta-sirnas are transcribed from genomic loci and require processing by micrornas (mirnas). cis-nat-sirnas are derived from antisense rnas produced by the simultaneous transcription of overlapping antisense genes. their roles in many plant processes, including pathogen response, are mostly unknown. in this work ... | 2013 | 23665476 |
| lectin receptor kinases in plant innate immunity. | a key feature of innate immunity is the ability to recognize and respond to potential pathogens in a highly sensitive and specific manner. in plants, the first layer of defense is induced after recognition by pattern recognition receptors of microbe-associated molecular patterns. this recognition elicits a defense program known as pattern-triggered immunity. pathogen entry into host tissue is a critical early step in causing infection. for foliar bacterial pathogens, natural surface openings suc ... | 2013 | 23675375 |
| calcium-dependent protein kinase/nadph oxidase activation circuit is required for rapid defense signal propagation. | in animals and plants, pathogen recognition triggers the local activation of intracellular signaling that is prerequisite for mounting systemic defenses in the whole organism. we identified that arabidopsis thaliana isoform cpk5 of the plant calcium-dependent protein kinase family becomes rapidly biochemically activated in response to pathogen-associated molecular pattern (pamp) stimulation. cpk5 signaling resulted in enhanced salicylic acid-mediated resistance to the bacterial pathogen pst dc30 ... | 2013 | 23650383 |
| wrky8 transcription factor functions in the tmv-cg defense response by mediating both abscisic acid and ethylene signaling in arabidopsis. | wrky transcription factors are key players in the plant immune response, but less is known about their involvement in antiviral defense than about their roles in defense against bacterial or fungi pathogens. here, we report that arabidopsis thaliana wrky dna-binding protein 8 (wrky8) has a role in mediating the long-distance movement of crucifer-infecting tobacco mosaic virus (tmv-cg). the expression of wrky8 was inhibited by tmv-cg infection, and mutation of wrky8 accelerated the accumulation o ... | 2013 | 23650359 |
| combined effect of a peptide-morpholino oligonucleotide conjugate and a cell-penetrating peptide as an antibiotic. | a cell-penetrating peptide (cpp)-morpholino oligonucleotide (mo) conjugate (pmo) that has an antibiotic effect in culture had some contaminating cpps in earlier preparations. the mixed conjugate had gene-specific and gene-nonspecific effects. an improved purification procedure separates the pmo from the free cpp and mo. the gene-specific effects are a result of the pmo, and the nonspecific effects are a result of the unlinked, unreacted cpp. the pmo and the cpp can be mixed together, as has been ... | 2013 | 23650357 |
| induced resistance in tomato by sar activators during predisposing salinity stress. | plant activators are chemicals that induce disease resistance. the phytohormone salicylic acid (sa) is a crucial signal for systemic acquired resistance (sar), and sa-mediated resistance is a target of several commercial plant activators, including actigard (1,2,3-benzothiadiazole-7-thiocarboxylic acid-s-methyl-ester, bth) and tiadinil [n-(3-chloro-4-methylphenyl)-4-methyl-1,2,3-thiadiazole-5-carboxamide, tdl]. bth and tdl were examined for their impact on abscisic acid (aba)-mediated, salt-indu ... | 2013 | 23653630 |
| genome-wide organization and expression profiling of the nac transcription factor family in potato (solanum tuberosum l.). | nac [no apical meristem (nam), arabidopsis thaliana transcription activation factor [ataf1/2] and cup-shaped cotyledon (cuc2)] proteins belong to one of the largest plant-specific transcription factor (tf) families and play important roles in plant development processes, response to biotic and abiotic cues and hormone signalling. our genome-wide analysis identified 110 stnac genes in potato encoding for 136 proteins, including 14 membrane-bound tfs. the physical map positions of stnac genes on 1 ... | 2013 | 23649897 |
| high cytokinin levels induce a hypersensitive-like response in tobacco. | cytokinins are positive regulators of shoot development. however, it has previously been demonstrated that efficient activation of the cytokinin biosynthesis gene ipt can cause necrotic lesions and wilting in tobacco leaves. some plant pathogens reportedly use their ability to produce cytokinins in disease development. in response to pathogen attacks, plants can trigger a hypersensitive response that rapidly kills cells near the infection site, depriving the pathogen of nutrients and preventing ... | 2013 | 23644362 |
| ubiquitin-specific proteases ubp12 and ubp13 act in circadian clock and photoperiodic flowering regulation in arabidopsis. | protein ubiquitination is involved in most cellular processes. in arabidopsis (arabidopsis thaliana), ubiquitin-mediated protein degradation regulates the stability of key components of the circadian clock feedback loops and the photoperiodic flowering pathway. here, we identified two ubiquitin-specific proteases, ubp12 and ubp13, involved in circadian clock and photoperiodic flowering regulation. double mutants of ubp12 and ubp13 display pleiotropic phenotypes, including early flowering and sho ... | 2013 | 23645632 |
| drought stress acclimation imparts tolerance to sclerotinia sclerotiorum and pseudomonas syringae in nicotiana benthamiana. | acclimation of plants with an abiotic stress can impart tolerance to some biotic stresses. such a priming response has not been widely studied. in particular, little is known about enhanced defense capacity of drought stress acclimated plants to fungal and bacterial pathogens. here we show that prior drought acclimation in nicotiana benthamiana plants imparts tolerance to necrotrophic fungus, sclerotinia sclerotiorum, and also to hemi-biotrophic bacterial pathogen, pseudomonas syringae pv. tabac ... | 2013 | 23644883 |
| exploitation of eukaryotic subcellular targeting mechanisms by bacterial effectors. | several bacterial species have evolved specialized secretion systems to deliver bacterial effector proteins into eukaryotic cells. these effectors have the capacity to modulate host cell pathways in order to promote bacterial survival and replication. the spatial and temporal context in which the effectors exert their biochemical activities is crucial for their function. to fully understand effector function in the context of infection, we need to understand the mechanisms that lead to the preci ... | 2013 | 23588250 |
| glycine betaine catabolism contributes to pseudomonas syringae tolerance to hyperosmotic stress by relieving betaine-mediated suppression of compatible solute synthesis. | many bacteria can accumulate glycine betaine for osmoprotection and catabolize it as a growth substrate, but how they regulate these opposing roles is poorly understood. in pseudomonas syringae b728a, expression of the betaine catabolism genes was reduced by an osmotic upshift to an intermediate stress level, consistent with betaine accumulation, but was increased by an upshift to a high stress level, as confirmed by an accompanying increase in degradation of radiolabeled betaine. deletion of th ... | 2013 | 23524610 |
| peln is a new pectate lyase of dickeya dadantii with unusual characteristics. | the plant-pathogenic bacterium dickeya dadantii produces several pectinolytic enzymes that play a major role in the soft-rot disease. eight characterized endopectate lyases are secreted in the extracellular medium by the type ii secretion system, out. they cleave internal glycosidic bonds of pectin, leading to plant tissue maceration. the d. dadantii pectate lyases belong to different families, namely, pl1, pl2, pl3, and pl9. analysis of the d. dadantii 3937 genome revealed a gene encoding a new ... | 2013 | 23475966 |
| oxylipin biosynthesis genes positively regulate programmed cell death during compatible infections with the synergistic pair potato virus x-potato virus y and tomato spotted wilt virus. | one of the most severe symptoms caused by compatible plant-virus interactions is systemic necrosis, which shares common attributes with the hypersensitive response to incompatible pathogens. although several studies have identified viral symptom determinants responsible for systemic necrosis, mechanistic models of how they contribute to necrosis in infected plants remain scarce. here, we examined the involvement of different branches of the oxylipin biosynthesis pathway in the systemic necrosis ... | 2013 | 23487466 |
| prospects for advancing defense to cereal rusts through genetical genomics. | rusts are one of the most severe threats to cereal crops because new pathogen races emerge regularly, resulting in infestations that lead to large yield losses. in 1999, a new race of stem rust, puccinia graminis f. sp. tritici (pgt ttksk or ug99), was discovered in uganda. most of the wheat and barley cultivars grown currently worldwide are susceptible to this new race. pgt ttksk has already spread northward into iran and will likely spread eastward throughout the indian subcontinent in the nea ... | 2013 | 23641250 |
| characterization of the achromobactin iron acquisition operon in sodalis glossinidius. | sodalis glossinidius is a facultative, extra- and intracellular symbiont found in most tissues of the tsetse fly (glossinia sp.). sodalis has a putative achromobactin siderophore iron acquisition system on the psg1 plasmid. reverse transcription (rt)-pcr analysis revealed that the achromobactin operon is transcribed as a single polycistronic molecule and is expressed when sodalis is within the tsetse fly. expression of the achromobactin operon was repressed under iron-replete conditions; in a mu ... | 2013 | 23435882 |
| the pseudomonas syringae type iii effector avrrpt2 promotes pathogen virulence via stimulating arabidopsis auxin/indole acetic acid protein turnover. | to accomplish successful infection, pathogens deploy complex strategies to interfere with host defense systems and subvert host physiology to favor pathogen survival and multiplication. modulation of plant auxin physiology and signaling is emerging as a common virulence strategy for phytobacteria to cause diseases. however, the underlying mechanisms remain largely elusive. we have previously shown that the pseudomonas syringae type iii effector avrrpt2 alters arabidopsis (arabidopsis thaliana) a ... | 2013 | 23632856 |
| identification of lens culinaris defense genes responsive to the anthracnose pathogen colletotrichum truncatum. | anthracnose of lentil, caused by the hemibiotrophic fungal pathogen colletotrichum truncatum is a serious threat to lentil production in western canada. colletotrichum truncatum employs a bi-phasic infection strategy characterized by initial symptomless biotrophic and subsequent destructive necrotrophic colonization of its host. the transition from biotrophy to necrotrophy (known as the biotrophy-necrotrophy switch [bns]) is critical in anthracnose development. understanding plant responses duri ... | 2013 | 23631759 |
| quantitative proteomics of tomato defense against pseudomonas syringae infection. | genetic and microarray analyses have provided useful information in the area of plant and pathogen interactions. pseudomonas syringae pv. tomato dc3000 (pst) causes bacterial speck disease in tomato. previous studies have shown that changes in response to pathogen infection at transcript level are variable at different time points. this study provides information not only on proteomic changes between a resistant and a susceptible genotype, but also information on changes between an early and a l ... | 2013 | 23533086 |
| myb transcription factor genes as regulators for plant responses: an overview. | regulation of gene expression at the level of transcription controls many crucial biological processes. transcription factors (tfs) play a great role in controlling cellular processes and myb tf family is large and involved in controlling various processes like responses to biotic and abiotic stresses, development, differentiation, metabolism, defense etc. here, we review myb tfs with particular emphasis on their role in controlling different biological processes. this will provide valuable insi ... | 2013 | 24431500 |
| exopolymer diversity and the role of levan in bacillus subtilis biofilms. | exopolymeric substances (eps) are important for biofilm formation and their chemical composition may influence biofilm properties. to explore these relationships the chemical composition of eps from bacillus subtilis ncib 3610 biofilms grown in sucrose-rich (sym) and sucrose-poor (msgg and czapek) media was studied. we observed marked differences in composition of eps polymers isolated from all three biofilms or from spent media below the biofilms. the polysaccharide levan dominated the eps of s ... | 2013 | 23637960 |
| ectopic expression of atpad4 broadens resistance of soybean to soybean cyst and root-knot nematodes. | the gene encoding pad4 (phytoalexin-deficient4) is required in arabidopsis for expression of several genes involved in the defense response to pseudomonas syringae pv. maculicola. atpad4 (arabidopsis thaliana pad4) encodes a lipase-like protein that plays a regulatory role mediating salicylic acid signaling. | 2013 | 23617694 |
| genetic requirements for signaling from an autoactive plant nb-lrr intracellular innate immune receptor. | plants react to pathogen attack via recognition of, and response to, pathogen-specific molecules at the cell surface and inside the cell. pathogen effectors (virulence factors) are monitored by intracellular nucleotide-binding leucine-rich repeat (nb-lrr) sensor proteins in plants and mammals. here, we study the genetic requirements for defense responses of an autoactive mutant of adr1-l2, an arabidopsis coiled-coil (cc)-nb-lrr protein. adr1-l2 functions upstream of salicylic acid (sa) accumulat ... | 2013 | 23633962 |
| the brassinosteroid signaling pathway-new key players and interconnections with other signaling networks crucial for plant development and stress tolerance. | brassinosteroids (brs) are a class of steroid hormones regulating a wide range of physiological processes during the plant life cycle from seed development to the modulation of flowering and senescence. the last decades, and recent years in particular, have witnessed a significant advance in the elucidation of the molecular mechanisms of br signaling from perception by the transmembrane receptor complex to the regulation of transcription factors influencing expression of the target genes. applic ... | 2013 | 23615468 |
| binding protein is a master regulator of the endoplasmic reticulum stress sensor/transducer bzip28 in arabidopsis. | binding protein (bip) is a major chaperone in the endoplasmic reticulum (er) lumen, and this study shows that bip binds to the c-terminal tail of the stress sensor/transducer bzip28, a membrane-associated transcription factor, retaining it in the er under unstressed conditions. in response to er stress, bip dissociates from bzip28, allowing it to be mobilized from the er to the golgi where it is proteolytically processed and released to enter the nucleus. under unstressed conditions, bip binds t ... | 2013 | 23624714 |
| novel α-msh peptide analogues with broad spectrum antimicrobial activity. | previous investigations indicate that α-melanocyte-stimulating hormone (α-msh) and certain synthetic analogues of it exert antimicrobial effects against bacteria and yeasts. however, these molecules have weak activity in standard microbiology conditions and this hampers a realistic clinical use. the aim in the present study was to identify novel peptides with broad-spectrum antimicrobial activity in growth medium. to this purpose, the gly10 residue in the [dnal(2')-7, phe-12]-msh(6-13) sequence ... | 2013 | 23626703 |
| reducing asa leads to leaf lesion and defence response in knock-down of the asa biosynthetic enzyme gdp-d-mannose pyrophosphorylase gene in tomato plant. | as a vital antioxidant, l-ascorbic acid (asa) affects diverse biological processes in higher plants. lack of asa in cell impairs plant development. in the present study, we manipulated a gene of gdp-mannose pyrophosphorylase which catalyzes the conversion of d-mannose-1-p to gdp-d-mannose in asa biosynthetic pathway and found out the phenotype alteration of tomato. in the tomato genome, there are four members of gmp gene family and they constitutively expressed in various tissues in distinct exp ... | 2013 | 23626761 |
| sensing temperature. | temperature is an omnipresent physical variable reflecting the rotational, vibrational and translational motion of matter, what richard feynman called the "jiggling" of atoms. temperature varies across space and time, and this variation has dramatic effects on the physiology of living cells. it changes the rate and nature of chemical reactions, and it alters the configuration of the atoms that make up nucleic acids, proteins, lipids and other biomolecules, significantly affecting their activity. ... | 2013 | 23618661 |
| just in time: circadian defense patterns and the optimal defense hypothesis. | the optimal defense hypothesis (odh) provides a functional explanation for the inhomogeneous distribution of defensive structures and defense metabolites throughout a plant's body: tissues that are most valuable in terms of fitness and have the highest probability of attack are generally the best defended. in a previous review, we argue that ontogenically-controlled accumulations of defense metabolites are likely regulated through an integration of developmental and defense signaling pathways. i ... | 2013 | 23603968 |
| one shot-two pathogens blocked: exposure of arabidopsis to hexadecane, a long chain volatile organic compound, confers induced resistance against both pectobacterium carotovorum and pseudomonas syringae. | bacteria and plant derived volatile organic compounds have been reported as the chemical triggers that elicit induced resistance in plants. previously, volatile organic compounds (vocs), including acetoin and 2,3-butanediol, were found to be emitted from plant growth-promoting rhizobacteria (pgpr) bacillus subtilis gb03, which had been shown to elicit isr and plant growth promotion. more recently, we reported data that stronger induced resistance could be elicited against pseudomonas syringae pv ... | 2013 | 23603940 |
| evolution and variability of solanum rangap2, a cofactor in the incompatible interaction between the resistance protein gpa2 and the globodera pallida effector gp-rbp-1. | the ran gtpase activating protein 2 (rangap2) was first described as a regulator of mitosis and nucleocytoplasmic trafficking. it was then found to interact with the coiled-coil domain of the rx and gpa2 resistance proteins, which confer resistance to potato virus x (pvx) and potato cyst nematode globodera pallida, respectively. rangap2 is thought to mediate recognition of the avirulence protein gp-rbp-1 by gpa2. however, the gpa2-induced hypersensitive response appears to be relatively weak and ... | 2013 | 23601377 |
| dual action of bpc194: a membrane active peptide killing bacterial cells. | membrane active peptides can perturb the lipid bilayer in several ways, such as poration and fusion of the target cell membrane, and thereby efficiently kill bacterial cells. we probe here the mechanistic basis of membrane poration and fusion caused by membrane-active, antimicrobial peptides. we show that the cyclic antimicrobial peptide, bpc194, inhibits growth of gram-negative bacteria and ruptures the outer and inner membrane at the onset of killing, suggesting that not just poration is takin ... | 2013 | 23620763 |
| suppression of plant defense responses by extracellular metabolites from pseudomonas syringae pv. tabaci in nicotiana benthamiana. | pseudomonas syringae pv. tabaci (pstab) is the causal agent of wildfire disease in tobacco plants. several pathovars of pseudomonas syringae produce a phytotoxic extracellular metabolite called coronatine (cor). cor has been shown to suppress plant defense responses. interestingly, pstab does not produce cor but still actively suppresses early plant defense responses. it is not clear if pstab produces any extracellular metabolites that actively suppress early defense during bacterial pathogenesi ... | 2013 | 23597256 |
| mutations in fls2 ser-938 dissect signaling activation in fls2-mediated arabidopsis immunity. | flagellin-sensing 2 (fls2) is a leucine-rich repeat/transmembrane domain/protein kinase (lrr-rlk) that is the plant receptor for bacterial flagellin or the flagellin-derived flg22 peptide. previous work has shown that after flg22 binding, fls2 releases bik1 kinase and homologs and associates with bak1 kinase, and that fls2 kinase activity is critical for fls2 function. however, the detailed mechanisms for activation of fls2 signaling remain unclear. the present study initially identified multipl ... | 2013 | 23637603 |
| functional redundancy and divergence within the arabidopsis reticulata-related gene family. | a number of arabidopsis (arabidopsis thaliana) mutants exhibit leaf reticulation, having green veins that stand out against paler interveinal tissues, fewer cells in the interveinal mesophyll, and normal perivascular bundle sheath cells. here, to examine the basis of leaf reticulation, we analyzed the arabidopsis reticulata-related (rer) gene family, several members of which cause leaf reticulation when mutated. although transcripts of re, rer1, and rer3 were mainly detected in the bundle sheath ... | 2013 | 23596191 |
| light-induced acclimation of the arabidopsis chlorina1 mutant to singlet oxygen. | singlet oxygen (¹o₂) is a reactive oxygen species that can function as a stress signal in plant leaves leading to programmed cell death. in microalgae, ¹o₂-induced transcriptomic changes result in acclimation to ¹o₂. here, using a chlorophyll b-less arabidopsis thaliana mutant (chlorina1 [ch1]), we show that this phenomenon can also occur in vascular plants. the ch1 mutant is highly photosensitive due to a selective increase in the release of ¹o₂ by photosystem ii. under photooxidative stress co ... | 2013 | 23590883 |
| arabidopsis phospholipase dβ1 modulates defense responses to bacterial and fungal pathogens. | pathogen infection of higher plants often induces rapid production of phosphatidic acid (pa) and changes in lipid profiles, but the enzymatic basis and the function of the lipid change in pathogen-plant interactions are not well understood. infection of phospholipase d β1 (pldβ1)-deficient plants by pseudomonas syringae tomato pv dc3000 (pst dc30000) resulted in less bacterial growth than in wild-type plants, and the effect was more profound in virulent pst dc3000 than avirulent pst dc3000 (carr ... | 2013 | 23577648 |
| role of homeodomain leucine zipper (hd-zip) iv transcription factors in plant development and plant protection from deleterious environmental factors. | homeobox genes comprise an important group of genes that are responsible for regulation of developmental processes. these genes determine cell differentiation and cell fate in all eukaryotic organisms, starting from the early stages of embryo development. homeodomain leucine zipper (hd-zip) transcription factors are unique to the plant kingdom. members of the hd-zip iv subfamily have a complex domain topology and can bind several cis-elements with overlapping sequences. many of the reported hd-z ... | 2013 | 23584027 |
| candidatus liberibacter americanus induces significant reprogramming of the transcriptome of the susceptible citrus genotype. | citrus huanglongbing (hlb) disease is caused by endogenous, phloem-restricted, gram negative, uncultured bacteria named candidatus liberibacter africanus (calaf), ca. l. asiaticus (calas), and ca. l. americanus (calam), depending on the continent where the bacteria were first detected. the asian citrus psyllid vector, diaphorina citri, transmits calas and calam and both liberibacter species are present in brazil. several studies of the transcriptional response of citrus plants manifesting hlb sy ... | 2013 | 23586643 |
| plant systemic induced responses mediate interactions between root parasitic nematodes and aboveground herbivorous insects. | insects and nematodes are the most diverse and abundant groups of multicellular animals feeding on plants on either side of the soil-air interface. several herbivore-induced responses are systemic, and hence can influence the preference and performance of organisms in other plant organs. recent studies show that plants mediate interactions between belowground plant parasitic nematodes (ppns) and aboveground herbivorous insects. based on the knowledge of plant responses to pathogens, we review th ... | 2013 | 23630532 |