| empty pericarp4 encodes a mitochondrion-targeted pentatricopeptide repeat protein necessary for seed development and plant growth in maize. | the pentatricopeptide repeat (ppr) family represents one of the largest gene families in plants, with >440 members annotated in arabidopsis thaliana. ppr proteins are thought to have a major role in the regulation of posttranscriptional processes in organelles. recent studies have shown that arabidopsis ppr proteins play an essential, nonredundant role during embryogenesis. here, we demonstrate that mutations in empty pericarp4 (emp4), a maize (zea mays) ppr-encoding gene, confer a seed-lethal p ... | 2007 | 17259266 |
| arabidopsis wee1 kinase controls cell cycle arrest in response to activation of the dna integrity checkpoint. | upon the incidence of dna stress, the ataxia telangiectasia-mutated (atm) and rad3-related (atr) signaling kinases activate a transient cell cycle arrest that allows cells to repair dna before proceeding into mitosis. although the atm-atr pathway is highly conserved over species, the mechanisms by which plant cells stop their cell cycle in response to the loss of genome integrity are unclear. we demonstrate that the cell cycle regulatory wee1 kinase gene of arabidopsis thaliana is transcriptiona ... | 2007 | 17209125 |
| the kinesin atk5 functions in early spindle assembly in arabidopsis. | during cell division, the mitotic spindle partitions chromosomes into daughter nuclei. in higher plants, the molecular mechanisms governing spindle assembly and function remain largely unexplored. here, live cell imaging of mitosis in arabidopsis thaliana plants lacking a kinesin-14 (atk5) reveals defects during early spindle formation. beginning during prophase and lasting until late prometaphase, spindles of atk5-1 plants become abnormally elongated, are frequently bent, and have splayed poles ... | 2007 | 17220198 |
| the arabidopsis irregular xylem8 mutant is deficient in glucuronoxylan and homogalacturonan, which are essential for secondary cell wall integrity. | the secondary cell wall in higher plants consists mainly of cellulose, lignin, and xylan and is the major component of biomass in many species. the arabidopsis thaliana irregular xylem8 (irx8) mutant is dwarfed and has a significant reduction in secondary cell wall thickness. irx8 belongs to a subgroup of glycosyltransferase family 8 called the gaut1-related gene family, whose members include gaut1, a homogalacturonan galacturonosyltransferase, and gaut12 (irx8). here, we use comparative cell wa ... | 2007 | 17237350 |
| nac transcription factors, nst1 and nst3, are key regulators of the formation of secondary walls in woody tissues of arabidopsis. | wood is formed by the successive addition of secondary xylem, which consists of cells with a conspicuously thickened secondary wall composed mainly of lignin and cellulose. several genes involved in lignin and cellulose biosynthesis have been characterized, but the factors that regulate the formation of secondary walls in woody tissues remain to be identified. in this study, we show that plant-specific transcription factors, designated nac secondary wall thickening promoting factor1 (nst1) and n ... | 2007 | 17237351 |
| arabidopsis pldzeta2 regulates vesicle trafficking and is required for auxin response. | phospholipase d (pld) and its product, phosphatidic acid (pa), play key roles in cellular processes, including stress and hormonal responses, vesicle trafficking, and cytoskeletal rearrangements. we isolated and functionally characterized arabidopsis thaliana pldzeta2, which is expressed in various tissues and enhanced by auxin. a pldzeta2-defective mutant, pldzeta2, and transgenic plants deficient in pldzeta2 were less sensitive to auxin, had reduced root gravitropism, and suppressed auxin-depe ... | 2007 | 17259265 |
| the acyltransferase gpat5 is required for the synthesis of suberin in seed coat and root of arabidopsis. | suberin and cutin are fatty acid- and glycerol-based plant polymers that act as pathogen barriers and function in the control of water and solute transport. however, despite important physiological roles, their biosynthetic pathways, including the acyl transfer reactions, remain hypothetical. we report the characterization of two suberin mutants (gpat5-1 and gpat5-2) of arabidopsis thaliana gpat5, encoding a protein with acyl-coa:glycerol-3-phosphate acyltransferase activity. rt-pcr and beta-glu ... | 2007 | 17259262 |
| a heat-inducible transcription factor, hsfa2, is required for extension of acquired thermotolerance in arabidopsis. | the expression of heat shock proteins (hsps) induced by nonlethal heat treatment confers acquired thermotolerance (at) to organisms against subsequent challenges of otherwise lethal temperature. after the stress signal is removed, at gradually decays, with decreased hsps during recovery. at of sufficient duration is critical for sessile organisms such as plants to survive repeated heat stress in their environment, but little is known regarding its regulation. to identify potential regulatory com ... | 2007 | 17085506 |
| degradation of oxidized proteins by autophagy during oxidative stress in arabidopsis. | upon encountering oxidative stress, proteins are oxidized extensively by highly reactive and toxic reactive oxidative species, and these damaged, oxidized proteins need to be degraded rapidly and effectively. there are two major proteolytic systems for bulk degradation in eukaryotes, the proteasome and vacuolar autophagy. in mammalian cells, the 20s proteasome and a specific type of vacuolar autophagy, chaperone-mediated autophagy, are involved in the degradation of oxidized proteins in mild oxi ... | 2007 | 17098847 |
| mikc* mads-protein complexes bind motifs enriched in the proximal region of late pollen-specific arabidopsis promoters. | the genome of arabidopsis (arabidopsis thaliana) encodes over 100 mads-domain transcription factors, categorized into five phylogenetic subgroups. most research efforts have focused on just one of these subgroups (mikc(c)), whereas the other four remain largely unexplored. here, we report on five members of the so-called mdelta or arabidopsis mikc* (atmikc*) subgroup, which are predominantly expressed during the late stages of pollen development. very few mads-box genes function in mature pollen ... | 2007 | 17071640 |
| tissue specific response of agrobacterium tumefaciens attachment to sorghum bicolor (l) moench. | agrobacterium mediated genetic transformation of plants have advantages over other methods, especially for making single copy transgenic plants with reduced chances of gene silencing and instability. however, monocotyledonous plant species could not utilize the full potential of this system because of possible limitations in agrobacterium interaction with monocot plant cells. agrobacterium attachment as a factor in genetic transformation was studied in the leaf, shoot apex, and leaf derived call ... | 2008 | 23572896 |
| tissue specific response of agrobacterium tumefaciens attachment to sorghum bicolor (l) moench. | agrobacterium mediated genetic transformation of plants have advantages over other methods, especially for making single copy transgenic plants with reduced chances of gene silencing and instability. however, monocotyledonous plant species could not utilize the full potential of this system because of possible limitations in agrobacterium interaction with monocot plant cells. agrobacterium attachment as a factor in genetic transformation was studied in the leaf, shoot apex, and leaf derived call ... | 2008 | 23572896 |
| efficient mitochondrial targeting relies on co-operation of multiple protein signals in plants. | to date, the most prevalent model for transport of pre-proteins to plant mitochondria is based on the activity of an n-terminal extension serving as a targeting peptide. whether the efficient delivery of proteins to mitochondria is based exclusively on the action of the n-terminal extension or also on that of other protein determinants has yet to be defined. a novel mechanism is reported here for the targeting of a plant protein, named mits1, to mitochondria. it was found that mits1 contains an ... | 2008 | 19112171 |
| efficient mitochondrial targeting relies on co-operation of multiple protein signals in plants. | to date, the most prevalent model for transport of pre-proteins to plant mitochondria is based on the activity of an n-terminal extension serving as a targeting peptide. whether the efficient delivery of proteins to mitochondria is based exclusively on the action of the n-terminal extension or also on that of other protein determinants has yet to be defined. a novel mechanism is reported here for the targeting of a plant protein, named mits1, to mitochondria. it was found that mits1 contains an ... | 2008 | 19112171 |
| silencing of stkcs6 in potato periderm leads to reduced chain lengths of suberin and wax compounds and increased peridermal transpiration. | very long chain aliphatic compounds occur in the suberin polymer and associated wax. up to now only few genes involved in suberin biosynthesis have been identified. this is a report on the isolation of a potato (solanum tuberosum) 3-ketoacyl-coa synthase (kcs) gene and the study of its molecular and physiological relevance by means of a reverse genetic approach. this gene, called stkcs6, was stably silenced by rna interference (rnai) in potato. analysis of the chemical composition of silenced po ... | 2008 | 19112170 |
| silencing of stkcs6 in potato periderm leads to reduced chain lengths of suberin and wax compounds and increased peridermal transpiration. | very long chain aliphatic compounds occur in the suberin polymer and associated wax. up to now only few genes involved in suberin biosynthesis have been identified. this is a report on the isolation of a potato (solanum tuberosum) 3-ketoacyl-coa synthase (kcs) gene and the study of its molecular and physiological relevance by means of a reverse genetic approach. this gene, called stkcs6, was stably silenced by rna interference (rnai) in potato. analysis of the chemical composition of silenced po ... | 2008 | 19112170 |
| regulated nuclear trafficking of rpl10a mediated by nik1 represents a defense strategy of plant cells against virus. | the nsp-interacting kinase (nik) receptor-mediated defense pathway has been identified recently as a virulence target of the geminivirus nuclear shuttle protein (nsp). however, the nik1-nsp interaction does not fit into the elicitor-receptor model of resistance, and hence the molecular mechanism that links this antiviral response to receptor activation remains obscure. here, we identified a ribosomal protein, rpl10a, as a specific partner and substrate of nik1 that functions as an immediate down ... | 2008 | 19112492 |
| topoisomerase 3alpha and rmi1 suppress somatic crossovers and are essential for resolution of meiotic recombination intermediates in arabidopsis thaliana. | topoisomerases are enzymes with crucial functions in dna metabolism. they are ubiquitously present in prokaryotes and eukaryotes and modify the steady-state level of dna supercoiling. biochemical analyses indicate that topoisomerase 3alpha (top3alpha) functions together with a recq dna helicase and a third partner, rmi1/blap75, in the resolution step of homologous recombination in a process called holliday junction dissolution in eukaryotes. apart from that, little is known about the role of top ... | 2008 | 19096507 |
| arabidopsis myb30 is a direct target of bes1 and cooperates with bes1 to regulate brassinosteroid-induced gene expression. | a paradox of plant hormone biology is how a single small molecule can affect a diverse array of growth and developmental processes. for instance, brassinosteroids (brs) regulate cell elongation, vascular differentiation, senescence and stress responses. brs signal through the bes1/bzr1 (bri1-ethylmethane sulphonate suppressor 1/brassinazole-resistant 1) family of transcription factors, which regulate hundreds of target genes involved in this pathway, yet little is known of this transcriptional n ... | 2008 | 19170933 |
| arabidopsis myb30 is a direct target of bes1 and cooperates with bes1 to regulate brassinosteroid-induced gene expression. | a paradox of plant hormone biology is how a single small molecule can affect a diverse array of growth and developmental processes. for instance, brassinosteroids (brs) regulate cell elongation, vascular differentiation, senescence and stress responses. brs signal through the bes1/bzr1 (bri1-ethylmethane sulphonate suppressor 1/brassinazole-resistant 1) family of transcription factors, which regulate hundreds of target genes involved in this pathway, yet little is known of this transcriptional n ... | 2008 | 19170933 |
| two negative cis-regulatory regions involved in fruit-specific promoter activity from watermelon (citrullus vulgaris s.). | a 1.8 kb 5'-flanking region of the large subunit of adp-glucose pyrophosphorylase, isolated from watermelon (citrullus vulgaris s.), has fruit-specific promoter activity in transgenic tomato plants. two negative regulatory regions, from -986 to -959 and from -472 to -424, were identified in this promoter region by fine deletion analyses. removal of both regions led to constitutive expression in epidermal cells. gain-of-function experiments showed that these two regions were sufficient to inhibit ... | 2008 | 19073962 |
| two negative cis-regulatory regions involved in fruit-specific promoter activity from watermelon (citrullus vulgaris s.). | a 1.8 kb 5'-flanking region of the large subunit of adp-glucose pyrophosphorylase, isolated from watermelon (citrullus vulgaris s.), has fruit-specific promoter activity in transgenic tomato plants. two negative regulatory regions, from -986 to -959 and from -472 to -424, were identified in this promoter region by fine deletion analyses. removal of both regions led to constitutive expression in epidermal cells. gain-of-function experiments showed that these two regions were sufficient to inhibit ... | 2008 | 19073962 |
| calcium-dependent freezing tolerance in arabidopsis involves membrane resealing via synaptotagmin syt1. | plant freezing tolerance involves the prevention of lethal freeze-induced damage to the plasma membrane. we hypothesized that plant freezing tolerance involves membrane resealing, which, in animal cells, is accomplished by calcium-dependent exocytosis following mechanical disruption of the plasma membrane. in arabidopsis thaliana protoplasts, extracellular calcium enhanced not only freezing tolerance but also tolerance to electroporation, which typically punctures the plasma membrane. however, c ... | 2008 | 19088330 |
| truncation of a protein disulfide isomerase, pdil2-1, delays embryo sac maturation and disrupts pollen tube guidance in arabidopsis thaliana. | pollen tubes must navigate through different female tissues to deliver sperm to the embryo sac for fertilization. protein disulfide isomerases play important roles in the maturation of secreted or plasma membrane proteins. here, we show that certain t-dna insertions in arabidopsis thaliana pdil2-1, a protein disulfide isomerase (pdi), have reduced seed set, due to delays in embryo sac maturation. reciprocal crosses indicate that these mutations acted sporophytically, and aniline blue staining an ... | 2008 | 19050167 |
| characterization of tctp, the translationally controlled tumor protein, from arabidopsis thaliana. | the translationally controlled tumor protein (tctp) is an important component of the tor (target of rapamycin) signaling pathway, the major regulator of cell growth in animals and fungi. tctp acts as the guanine nucleotide exchange factor of the ras gtpase rheb that controls tor activity in drosophila melanogaster. we therefore examined the role of arabidopsis thaliana tctp in planta. plant tctps exhibit distinct sequence differences from nonplant homologs but share the key gtpase binding surfac ... | 2008 | 19060111 |
| arabidopsis synaptotagmin 1 is required for the maintenance of plasma membrane integrity and cell viability. | plasma membrane repair in animal cells uses synaptotagmin 7, a ca(2+)-activated membrane fusion protein that mediates delivery of intracellular membranes to wound sites by a mechanism resembling neuronal ca(2+)-regulated exocytosis. here, we show that loss of function of the homologous arabidopsis thaliana synaptotagmin 1 protein (syt1) reduces the viability of cells as a consequence of a decrease in the integrity of the plasma membrane. this reduced integrity is enhanced in the syt1-2 null muta ... | 2008 | 19088329 |
| the c-terminal variable region specifies the dynamic properties of arabidopsis microtubule-associated protein map65 isotypes. | the microtubule-associated protein, map65, is a member of a family of divergent microtubule-associated proteins from different organisms generally involved in maintaining the integrity of the central spindle in mitosis. the dicotyledon arabidopsis thaliana and the monocotyledon rice (oryza sativa) genomes contain 9 and 11 map65 genes, respectively. in this work, we show that the majority of these proteins fall into five phylogenetic clades, with the greatest variation between clades being in the ... | 2008 | 19060108 |
| asymmetric leaves2-like19/lateral organ boundaries domain30 and asl20/lbd18 regulate tracheary element differentiation in arabidopsis. | asymmetric leaves2 (as2)/lateral organ boundaries domain (lbd) family proteins are plant-specific nuclear proteins, and genes encoding several family members have been implicated in plant development. we investigated the function of two members of the arabidopsis thaliana as2/lbd family, as2-like19 (asl19)/lbd30 and asl20/lbd18, which encode homologous proteins. both asl19 and asl20 were expressed in immature tracheary elements (tes), and the expression was dependent on vascular-related nac-doma ... | 2008 | 19088331 |
| unique and overlapping expression patterns among members of photosynthesis-associated nuclear gene families in arabidopsis. | light provides crucial positional information in plant development, and the morphogenetic processes that are orchestrated by light signals are triggered by changes of gene expression in response to variations in light parameters. control of expression of members of the rbcs and lhc families of photosynthesis-associated nuclear genes by light cues is a paradigm for light-regulated gene transcription, but high-resolution expression profiles for these gene families are lacking. in this study, we ha ... | 2008 | 18820083 |
| the deg15 serine protease cleaves peroxisomal targeting signal 2-containing proteins in arabidopsis. | two distinct peroxisomal targeting signals (ptss), the c-terminal pts1 and the n-terminal pts2, are defined. processing of the pts2 on protein import is conserved in higher eukaryotes. recently, candidates for the responsible processing protease were identified from plants (deg15) and mammals (tysnd1). we demonstrate that plants lacking deg15 show an expressed phenotype potentially linked to reduced beta-oxidation, indicating the impact of protein processing on peroxisomal functions in higher eu ... | 2008 | 18952862 |
| characterization of cytokinin and adenine transport in arabidopsis cell cultures. | cytokinins are distributed through the vascular system and trigger responses of target cells via receptor-mediated signal transduction. perception and transduction of the signal can occur at the plasma membrane or in the cytosol. the signal is terminated by the action of extra- or intracellular cytokinin oxidases. while radiotracer studies have been used to study transport and metabolism of cytokinins in plants, little is known about the kinetic properties of cytokinin transport. to provide a re ... | 2008 | 18835995 |
| transcriptome analysis of proliferating arabidopsis endosperm reveals biological implications for the control of syncytial division, cytokinin signaling, and gene expression regulation. | during the early stages of seed development, arabidopsis (arabidopsis thaliana) endosperm is syncytial and proliferates rapidly through repeated rounds of mitosis without cytokinesis. this stage of endosperm development is important in determining final seed size and is a model for studying aspects of cellular and molecular biology, such as the cell cycle and genomic imprinting. however, the small size of the arabidopsis seed makes high-throughput molecular analysis of the early endosperm techni ... | 2008 | 18923020 |
| a novel 2-oxoacid-dependent dioxygenase involved in the formation of the goiterogenic 2-hydroxybut-3-enyl glucosinolate and generalist insect resistance in arabidopsis,. | glucosinolates are secondary metabolites found almost exclusively in the order brassicales. they are synthesized from a variety of amino acids and can have numerous side chain modifications that control biological function. we investigated the biosynthesis of 2-hydroxybut-3-enyl glucosinolate, which has biological activities including toxicity to caenorhabditis elegans, inhibition of seed germination, induction of goiter disease in mammals, and production of bitter flavors in brassica vegetable ... | 2008 | 18945935 |
| the polygalacturonase gene bcmf2 from brassica campestris is associated with intine development. | brassica campestris male fertility 2 (bcmf2) is a putative polygalacturonase (pg) gene previously isolated from the flower bud of chinese cabbage (brassica campestris l. ssp. chinensis makino, syn. b. rapa ssp. chinensis). this gene was found to be expressed specifically in tapetum and pollen after the tetrad stage of anther development. antisense rna technology was used to study the function of bcmf2 in chinese cabbage. scanning and transmission electron microscopy revealed that there were defo ... | 2008 | 19039102 |
| the polygalacturonase gene bcmf2 from brassica campestris is associated with intine development. | brassica campestris male fertility 2 (bcmf2) is a putative polygalacturonase (pg) gene previously isolated from the flower bud of chinese cabbage (brassica campestris l. ssp. chinensis makino, syn. b. rapa ssp. chinensis). this gene was found to be expressed specifically in tapetum and pollen after the tetrad stage of anther development. antisense rna technology was used to study the function of bcmf2 in chinese cabbage. scanning and transmission electron microscopy revealed that there were defo ... | 2008 | 19039102 |
| arabidopsis at5g39790 encodes a chloroplast-localized, carbohydrate-binding, coiled-coil domain-containing putative scaffold protein. | starch accumulation and degradation in chloroplasts is accomplished by a suite of over 30 enzymes. recent work has emphasized the importance of multi-protein complexes amongst the metabolic enzymes, and the action of associated non-enzymatic regulatory proteins. arabidopsis at5g39790 encodes a protein of unknown function whose sequence was previously demonstrated to contain a putative carbohydrate-binding domain. | 2008 | 19038037 |
| gal4 gfp enhancer trap lines for analysis of stomatal guard cell development and gene expression. | to facilitate the monitoring of guard cells during development and isolation, a population of 704 gal4 gfp enhancer trap lines was screened and four single insert lines with guard cell gfp expression and one with developmentally-regulated guard cell gfp expression were identified. the location of the t-dna inserts, the expression of the flanking genes, and the promoter activity of the genomic dna upstream of the t-dna were characterized. the results indicated that the gfp expression pattern in a ... | 2008 | 19033548 |
| gal4 gfp enhancer trap lines for analysis of stomatal guard cell development and gene expression. | to facilitate the monitoring of guard cells during development and isolation, a population of 704 gal4 gfp enhancer trap lines was screened and four single insert lines with guard cell gfp expression and one with developmentally-regulated guard cell gfp expression were identified. the location of the t-dna inserts, the expression of the flanking genes, and the promoter activity of the genomic dna upstream of the t-dna were characterized. the results indicated that the gfp expression pattern in a ... | 2008 | 19033548 |
| morphological and molecular characterization of a spontaneously tuberizing potato mutant: an insight into the regulatory mechanisms of tuber induction. | tuberization in potato (solanum tuberosum l.) represents a morphogenetic transition of stolon growth to tuber formation, which is under complex environmental and endogenous regulation. in the present work, we studied the regulatory mechanisms and the role of different morphogenetic factors in a newly isolated potato mutant, which exhibited spontaneous tuberization (st). the st mutant was characterized in detail at morphological, physiological and biochemical levels. | 2008 | 19025587 |
| multiple plds required for high salinity and water deficit tolerance in plants. | high salinity and drought have received much attention because they severely affect crop production worldwide. analysis and comprehension of the plant's response to excessive salt and dehydration will aid in the development of stress-tolerant crop varieties. signal transduction lies at the basis of the response to these stresses, and numerous signaling pathways have been implicated. here, we provide further evidence for the involvement of phospholipase d (pld) in the plant's response to high sal ... | 2008 | 19017627 |
| multiple plds required for high salinity and water deficit tolerance in plants. | high salinity and drought have received much attention because they severely affect crop production worldwide. analysis and comprehension of the plant's response to excessive salt and dehydration will aid in the development of stress-tolerant crop varieties. signal transduction lies at the basis of the response to these stresses, and numerous signaling pathways have been implicated. here, we provide further evidence for the involvement of phospholipase d (pld) in the plant's response to high sal ... | 2008 | 19017627 |
| highly boron deficiency-tolerant plants generated by enhanced expression of nip5;1, a boric acid channel. | boron (b) is an essential element for plants, and b deficiency is a worldwide agricultural problem. in b-deficient areas, b is often supplied as fertilizer, but excess b can be toxic to both plants and animals. generation of b deficiency-tolerant plants could reduce b fertilizer use. improved fertility under b-limiting conditions in arabidopsis thaliana by overexpression of bor1, a b transporter, has been reported, but the root growth was not improved by the bor1 overexpression. in this study, w ... | 2008 | 19017629 |
| highly boron deficiency-tolerant plants generated by enhanced expression of nip5;1, a boric acid channel. | boron (b) is an essential element for plants, and b deficiency is a worldwide agricultural problem. in b-deficient areas, b is often supplied as fertilizer, but excess b can be toxic to both plants and animals. generation of b deficiency-tolerant plants could reduce b fertilizer use. improved fertility under b-limiting conditions in arabidopsis thaliana by overexpression of bor1, a b transporter, has been reported, but the root growth was not improved by the bor1 overexpression. in this study, w ... | 2008 | 19017629 |
| homologous recombination-mediated cloning and manipulation of genomic dna regions using gateway and recombineering systems. | employing genomic dna clones to characterise gene attributes has several advantages over the use of cdna clones, including the presence of native transcription and translation regulatory sequences as well as a representation of the complete repertoire of potential splice variants encoded by the gene. however, working with genomic dna clones has traditionally been tedious due to their large size relative to cdna clones and the presence, absence or position of particular restriction enzyme sites t ... | 2008 | 19014699 |
| a putative lipase gene extra glume1 regulates both empty-glume fate and spikelet development in rice. | recent studies have shown that molecular control of inner floral organ identity appears to be largely conserved between monocots and dicots, but little is known regarding the molecular mechanism underlying development of the monocot outer floral organ, a unique floral structure in grasses. in this study, we report the cloning of the rice extra glume1 (eg1) gene, a putative lipase gene that specifies empty-glume fate and floral meristem determinacy. in addition to affecting the identity and numbe ... | 2008 | 18980657 |
| a putative lipase gene extra glume1 regulates both empty-glume fate and spikelet development in rice. | recent studies have shown that molecular control of inner floral organ identity appears to be largely conserved between monocots and dicots, but little is known regarding the molecular mechanism underlying development of the monocot outer floral organ, a unique floral structure in grasses. in this study, we report the cloning of the rice extra glume1 (eg1) gene, a putative lipase gene that specifies empty-glume fate and floral meristem determinacy. in addition to affecting the identity and numbe ... | 2008 | 18980657 |
| arginine/lysine residues in the cytoplasmic tail promote er export of plant glycosylation enzymes. | plant n-glycan processing enzymes are arranged along the early secretory pathway, forming an assembly line to facilitate the step-by-step modification of oligosaccharides on glycoproteins. thus, these enzymes provide excellent tools to study signals and mechanisms, promoting their localization and retention in the endoplasmic reticulum (er) and golgi apparatus. herein, we focused on a detailed investigation of amino acid sequence motifs present in their short cytoplasmic tails in respect to er e ... | 2008 | 18939950 |
| arginine/lysine residues in the cytoplasmic tail promote er export of plant glycosylation enzymes. | plant n-glycan processing enzymes are arranged along the early secretory pathway, forming an assembly line to facilitate the step-by-step modification of oligosaccharides on glycoproteins. thus, these enzymes provide excellent tools to study signals and mechanisms, promoting their localization and retention in the endoplasmic reticulum (er) and golgi apparatus. herein, we focused on a detailed investigation of amino acid sequence motifs present in their short cytoplasmic tails in respect to er e ... | 2008 | 18939950 |
| characterization of a new rice glutelin gene glud-1 expressed in the starchy endosperm. | a new glutelin gene, designated glud-1, has been discovered by comparing the seed storage proteins from 48 japonica and indica rice cultivars on sds-page gels. evidence that glud-1 is a member of the glutelin family was provided by western blots using anti-glutelin antiserum and by mapping the gene to the chromosomal glutelin gene cluster. the limited glud-1 size polymorphism among the rice varieties is due to amino acid substitutions rather than to post-transcriptional modification. glud-1 is m ... | 2008 | 18980953 |
| comprehensive resources for tomato functional genomics based on the miniature model tomato micro-tom. | tomato (solanum lycopersicum l., solanaceae) is an excellent model plant for genomic research of solanaceous plants, as well as for studying the development, ripening, and metabolism of fruit. in 2003, the international solanaceae project (sol, www.sgn.cornell.edu ) was initiated by members from more than 30 countries, and the tomato genome-sequencing project is currently underway. genome sequence of tomato obtained by this project will provide a firm foundation for forthcoming genomic studies s ... | 2008 | 19506732 |
| hormonal changes in relation to biomass partitioning and shoot growth impairment in salinized tomato (solanum lycopersicum l.) plants. | following exposure to salinity, the root/shoot ratio is increased (an important adaptive response) due to the rapid inhibition of shoot growth (which limits plant productivity) while root growth is maintained. both processes may be regulated by changes in plant hormone concentrations. tomato plants (solanum lycopersicum l. cv moneymaker) were cultivated hydroponically for 3 weeks under high salinity (100 mm nacl) and five major plant hormones (abscisic acid, aba; the cytokinins zeatin, z, and ze ... | 2008 | 19036841 |
| a snare complex unique to seed plants is required for protein storage vacuole biogenesis and seed development of arabidopsis thaliana. | the snare complex is a key regulator of vesicular traffic, executing membrane fusion between transport vesicles or organelles and target membranes. a functional snare complex consists of four coiled-coil helical bundles, three of which are supplied by q-snares and another from an r-snare. arabidopsis thaliana vamp727 is an r-snare, with homologs only in seed plants. we have found that vamp727 colocalizes with syp22/ vam3, a q-snare, on a subpopulation of prevacuolar compartments/endosomes closel ... | 2008 | 18984676 |
| protein repair l-isoaspartyl methyltransferase 1 is involved in both seed longevity and germination vigor in arabidopsis. | the formation of abnormal amino acid residues is a major source of spontaneous age-related protein damage in cells. the protein l-isoaspartyl methyltransferase (pimt) combats protein misfolding resulting from l-isoaspartyl formation by catalyzing the conversion of abnormal l-isoaspartyl residues to their normal l-aspartyl forms. in this way, the pimt repair enzyme system contributes to longevity and survival in bacterial and animal kingdoms. despite the discovery of pimt activity in plants two d ... | 2008 | 19011119 |
| maternal control of male-gamete delivery in arabidopsis involves a putative gpi-anchored protein encoded by the lorelei gene. | in angiosperms, the male gametes are delivered to the female gametes through the maternal reproductive tissue by the pollen tube. upon arrival, the pollen tube releases the two sperm cells, permitting double fertilization to take place. although the critical role of the female gametophyte in pollen tube reception has been demonstrated, the underlying mechanisms remain poorly understood. here, we describe lorelei, an arabidopsis thaliana mutant impaired in sperm cell release, reminiscent of the f ... | 2008 | 19028964 |
| two leucine-rich repeat receptor kinases mediate signaling, linking cell wall biosynthesis and acc synthase in arabidopsis. | the plant cell wall is a dynamic structure that changes in response to developmental and environmental cues through poorly understood signaling pathways. we identified two leu-rich repeat receptor-like kinases in arabidopsis thaliana that play a role in regulating cell wall function. mutations in these fei1 and fei2 genes (named for the chinese word for fat) disrupt anisotropic expansion and the synthesis of cell wall polymers and act additively with inhibitors or mutations disrupting cellulose ... | 2008 | 19017745 |
| arabidopsis bzip60 is a proteolysis-activated transcription factor involved in the endoplasmic reticulum stress response. | proteins synthesized in the endoplasmic reticulum (er) of eukaryotic cells must be folded correctly before translocation out of the er. disruption of protein folding results in the induction of genes for er-resident chaperones, for example, bip. this phenomenon is known as the er stress response. we report here that bzip60, an arabidopsis thaliana basic leucine zipper (bzip) transcription factor with a transmembrane domain, is involved in the er stress response. when compared with wild-type arab ... | 2008 | 19017746 |
| a heterocomplex of iron superoxide dismutases defends chloroplast nucleoids against oxidative stress and is essential for chloroplast development in arabidopsis. | there are three iron superoxide dismutases in arabidopsis thaliana: fe superoxide dismutase1 (fsd1), fsd2, and fsd3. their biological roles in chloroplast development are unknown. here, we show that fsd2 and fsd3 play essential roles in early chloroplast development, whereas fsd1, which is found in the cytoplasm, does not. an fsd2-1 fsd3-1 double mutant had a severe albino phenotype on agar plates, whereas fsd2 and fsd3 single knockout mutants had pale green phenotypes. chloroplast development w ... | 2008 | 18996978 |
| exportin1 genes are essential for development and function of the gametophytes in arabidopsis thaliana. | gametes are produced in plants through mitotic divisions in the haploid gametophytes. we investigated the role of exportin1 (xpo1) genes during the development of both female and male gametophytes of arabidopsis. exportins exclude target proteins from the nucleus and are also part of a complex recruited at the kinetochores during mitosis. here we show that double mutants in arabidopsis xpo1a and xpo1b are gametophytic defective. in homozygous-heterozygous plants, 50% of the ovules were arrested ... | 2008 | 18791220 |
| functional analysis of the cellulose synthase-like genes csld1, csld2, and csld4 in tip-growing arabidopsis cells. | a reverse genetic approach was used to investigate the functions of three members of the cellulose synthase superfamily in arabidopsis (arabidopsis thaliana), cellulose synthase-like d1 (csld1), csld2, and csld4. csld2 is required for normal root hair growth but has a different role from that previously described for csld3 (kojak). csld2 is required during a later stage of hair development than csld3, and csld2 mutants produce root hairs with a range of abnormalities, with many root hairs ruptur ... | 2008 | 18768911 |
| subclade of flavin-monooxygenases involved in aliphatic glucosinolate biosynthesis. | glucosinolates (gsls) are amino acid-derived secondary metabolites with diverse biological activities dependent on chemical modifications of the side chain. we previously identified the flavin-monooxygenase fmo(gs-ox1) as an enzyme in the biosynthesis of aliphatic gsls in arabidopsis (arabidopsis thaliana) that catalyzes the s-oxygenation of methylthioalkyl to methylsulfinylalkyl gsls. here, we report the fine mapping of a quantitative trait locus for the s-oxygenating activity in arabidopsis. i ... | 2008 | 18799661 |
| the pollen receptor kinase leprk2 mediates growth-promoting signals and positively regulates pollen germination and tube growth. | in flowering plants, the process of pollen germination and tube growth is required for successful fertilization. a pollen receptor kinase from tomato (solanum lycopersicum), leprk2, has been implicated in signaling during pollen germination and tube growth as well as in mediating pollen (tube)-pistil communication. here we show that reduced expression of leprk2 affects four aspects of pollen germination and tube growth. first, the percentage of pollen that germinates is reduced, and the time win ... | 2008 | 18799662 |
| comparative analyses of arabidopsis complex glycan1 mutants and genetic interaction with staurosporin and temperature sensitive3a. | we compare three arabidopsis (arabidopsis thaliana) complex glycan1 (cgl1) alleles and report on genetic interaction with staurosporin and temperature sensitive3a (stt3a). stt3a encodes a subunit of oligosaccharyltransferase that affects efficiency of n-glycan transfer to nascent secretory proteins in the endoplasmic reticulum; cgl1 mutants lack n-acetyl-glucosaminyltransferase i activity and are unable to form complex n-glycans in the golgi apparatus. by studying cgl1-green fluorescent protein ... | 2008 | 18768906 |
| characterization of arabidopsis lines deficient in gapc-1, a cytosolic nad-dependent glyceraldehyde-3-phosphate dehydrogenase. | phosphorylating glyceraldehyde-3-p dehydrogenase (gapc-1) is a highly conserved cytosolic enzyme that catalyzes the conversion of glyceraldehyde-3-p to 1,3-bis-phosphoglycerate; besides its participation in glycolysis, it is thought to be involved in additional cellular functions. to reach an integrative view on the many roles played by this enzyme, we characterized a homozygous gapc-1 null mutant and an as-gapc1 line of arabidopsis (arabidopsis thaliana). both mutant plant lines show a delay in ... | 2008 | 18820081 |
| hfr1 is crucial for transcriptome regulation in the cryptochrome 1-mediated early response to blue light in arabidopsis thaliana. | cryptochromes are blue light photoreceptors involved in development and circadian clock regulation. they are found in both eukaryotes and prokaryotes as light sensors. long hypocotyl in far-red 1 (hfr1) has been identified as a positive regulator and a possible transcription factor in both blue and far-red light signaling in plants. however, the gene targets that are regulated by hfr1 in cryptochrome 1 (cry1)-mediated blue light signaling have not been globally addressed. we examined the transcr ... | 2008 | 18974779 |
| do transgenic plants affect rhizobacteria populations? | plant genetic manipulation has led to the development of genetically modified plants (gmps) expressing various traits. since their first commercial use in 1996, gmps have been increasingly used, reaching a global cultivating production area of 114.3 million hectares in 2007. the rapid development of agricultural biotechnology and release of gmps have provided many agronomic and economic benefits, but has also raised concerns over the potential impact these plants might have on the environment. a ... | 2008 | 21261867 |
| mutants of gaba transaminase (pop2) suppress the severe phenotype of succinic semialdehyde dehydrogenase (ssadh) mutants in arabidopsis. | the gamma-aminubutyrate (gaba) shunt bypasses two steps of the tricarboxylic acid cycle, and is present in both prokaryotes and eukaryotes. in plants, the pathway is composed of the calcium/calmodulin-regulated cytosolic enzyme glutamate decarboxylase (gad), the mitochondrial enzymes gaba transaminase (gaba-t; pop2) and succinic semialdehyde dehydrogenase (ssadh). we have previously shown that compromising the function of the gaba-shunt, by disrupting the ssadh gene of arabidopsis, causes enhanc ... | 2008 | 18846220 |
| antibody-mediated prevention of fusarium mycotoxins in the field. | fusarium mycotoxins directly accumulated in grains during the infection of wheat and other cereal crops by fusarium head blight (fhb) pathogens are detrimental to humans and domesticated animals. prevention of the mycotoxins via the development of fhb-resistant varieties has been a challenge due to the scarcity of natural resistance against fhb pathogens. various antibodies specific to fusarium fungi and mycotoxins are widely used in immunoassays and antibody-mediated resistance in planta agains ... | 2008 | 19325726 |
| overexpression of sos (salt overly sensitive) genes increases salt tolerance in transgenic arabidopsis. | soil salinity is a major abiotic stress that decreases plant growth and productivity. recently, it was reported that plants overexpressing atnhx1 or sos1 have significantly increased salt tolerance. to test whether overexpression of multiple genes can improve plant salt tolerance even more, we produced six different transgenic arabidopsis plants that overexpress atnhx1, sos3, atnhx1+sos3, sos1, sos2+sos3, or sos1+sos2+sos3. northern blot analyses confirmed the presence of high levels of the rele ... | 2008 | 19529826 |
| overexpression of sos (salt overly sensitive) genes increases salt tolerance in transgenic arabidopsis. | soil salinity is a major abiotic stress that decreases plant growth and productivity. recently, it was reported that plants overexpressing atnhx1 or sos1 have significantly increased salt tolerance. to test whether overexpression of multiple genes can improve plant salt tolerance even more, we produced six different transgenic arabidopsis plants that overexpress atnhx1, sos3, atnhx1+sos3, sos1, sos2+sos3, or sos1+sos2+sos3. northern blot analyses confirmed the presence of high levels of the rele ... | 2008 | 19529826 |
| biogenesis of cytoplasmic membranous vesicles for plant potyvirus replication occurs at endoplasmic reticulum exit sites in a copi- and copii-dependent manner. | single-stranded positive-sense rna viruses induce the biogenesis of cytoplasmic membranous vesicles, where viral replication takes place. however, the mechanism underlying this characteristic vesicular proliferation remains poorly understood. previously, a 6-kda potyvirus membrane protein (6k) was shown to interact with the endoplasmic reticulum (er) and to induce the formation of the membranous vesicles. in this study, the involvement of the early secretory pathway in the formation of the 6k-in ... | 2008 | 18842721 |
| the role of gtp binding and hydrolysis at the attoc159 preprotein receptor during protein import into chloroplasts. | the majority of nucleus-encoded chloroplast proteins are targeted to the organelle by direct binding to two membrane-bound gtpase receptors, toc34 and toc159. the gtpase activities of the receptors are implicated in two key import activities, preprotein binding and driving membrane translocation, but their precise functions have not been defined. we use a combination of in vivo and in vitro approaches to study the role of the toc159 receptor in the import reaction. we show that attoc159-a864r, a ... | 2008 | 18824565 |
| refinement of light-responsive transcript lists using rice oligonucleotide arrays: evaluation of gene-redundancy. | studies of gene function are often hampered by gene-redundancy, especially in organisms with large genomes such as rice (oryza sativa). we present an approach for using transcriptomics data to focus functional studies and address redundancy. to this end, we have constructed and validated an inexpensive and publicly available rice oligonucleotide near-whole genome array, called the rice nsf45k array. we generated expression profiles for light- vs. dark-grown rice leaf tissue and validated the bio ... | 2008 | 18836531 |
| differential expression and phylogenetic analysis suggest specialization of plastid-localized members of the pht4 phosphate transporter family for photosynthetic and heterotrophic tissues. | plastids rely on multiple phosphate (pi) transport activities to support and control a wide range of metabolic processes, including photosynthesis and carbon partitioning. five of the six members of the pht4 family of pi transporters in arabidopsis thaliana (pht4;1-pht4;5) are confirmed or predicted plastid proteins. as a step towards identifying the roles of individual pht4 pi transporters in chloroplast and non-photosynthetic plastid pi dynamics, we used promoter-reporter gene fusions and quan ... | 2008 | 19513231 |
| f-actin organization and pollen tube tip growth in arabidopsis are dependent on the gametophyte-specific armadillo repeat protein aro1. | the signal-mediated and spatially controlled assembly and dynamics of actin are crucial for maintaining shape, motility, and tip growth of eukaryotic cells. we report that a novel armadillo repeat protein in arabidopsis thaliana, armadillo repeat only1 (aro1), is of fundamental importance for polar growth and f-actin organization in tip-growing pollen tubes. aro1 is specifically expressed in the vegetative cell of pollen as well as in the egg cell. aro1-gfp (for green fluorescent protein) fusion ... | 2008 | 18931021 |
| a battery of transcription factors involved in the regulation of secondary cell wall biosynthesis in arabidopsis. | secondary wall-associated nac domain protein1 (snd1) is a master transcriptional switch activating the developmental program of secondary wall biosynthesis. here, we demonstrate that a battery of snd1-regulated transcription factors is required for normal secondary wall biosynthesis in arabidopsis thaliana. the expression of 11 snd1-regulated transcription factors, namely, snd2, snd3, myb103, myb85, myb52, myb54, myb69, myb42, myb43, myb20, and knat7 (a knotted1-like homeodomain protein), was de ... | 2008 | 18952777 |
| nac family proteins nars1/nac2 and nars2/nam in the outer integument regulate embryogenesis in arabidopsis. | seed morphogenesis consists of embryogenesis and the development of maternal tissues such as the inner and outer integuments, both of which give rise to seed coats. we show that expression of chimeric repressors derived from nac-regulated seed morphology1 and -2 (nars1 and nars2, also known as nac2 and nam, respectively) caused aberrant seed shapes in arabidopsis thaliana. double knockout mutant nars1 nars2 exhibited abnormally shaped seeds; moreover, neither nars1 nor nars2 produced abnormal se ... | 2008 | 18849494 |
| a novel class of gibberellin 2-oxidases control semidwarfism, tillering, and root development in rice. | gibberellin 2-oxidases (ga2oxs) regulate plant growth by inactivating endogenous bioactive gibberellins (gas). two classes of ga2oxs inactivate gas through 2beta-hydroxylation: a larger class of c(19) ga2oxs and a smaller class of c(20) ga2oxs. in this study, we show that members of the rice (oryza sativa) ga2ox family are differentially regulated and act in concert or individually to control ga levels during flowering, tillering, and seed germination. using mutant and transgenic analysis, c(20) ... | 2008 | 18952778 |
| the arabidopsis cop9 signalosome subunit 7 is a model pci domain protein with subdomains involved in cop9 signalosome assembly. | the cop9 signalosome (csn) is a multiprotein complex that was originally identified in arabidopsis thaliana as a negative regulator of photomorphogenesis and subsequently shown to be a general eukaryotic regulator of developmental signaling. the csn plays various roles, but it has been most often implicated in regulating protein degradation pathways. six of eight csn subunits bear a sequence motif called pci. here, we report studies of subunit 7 (csn7) from arabidopsis, which contains such a mot ... | 2008 | 18854373 |
| transgenic arabidopsis plants expressing the type 1 inositol 5-phosphatase exhibit increased drought tolerance and altered abscisic acid signaling. | the phosphoinositide pathway and inositol-1,4,5-trisphosphate (insp(3)) are implicated in plant responses to stress. to determine the downstream consequences of altered insp(3)-mediated signaling, we generated transgenic arabidopsis thaliana plants expressing the mammalian type i inositol polyphosphate 5-phosphatase (insp 5-ptase), which specifically hydrolyzes soluble inositol phosphates and terminates the signal. rapid transient ca(2+) responses to a cold or salt stimulus were reduced by appro ... | 2008 | 18849493 |
| the gibberellic acid signaling repressor rgl2 inhibits arabidopsis seed germination by stimulating abscisic acid synthesis and abi5 activity. | seed germination is antagonistically controlled by the phytohormones gibberellic acid (ga) and abscisic acid (aba). ga promotes seed germination by enhancing the proteasome-mediated destruction of rgl2 (for rga-like2), a key della factor repressing germination. by contrast, aba blocks germination by inducing abi5 (for aba-insensitive5), a basic domain/leucine zipper transcription factor repressing germination. decreased ga synthesis leads to an increase in endogenous aba levels through a stabili ... | 2008 | 18941053 |
| isoprenylcysteine methylation and demethylation regulate abscisic acid signaling in arabidopsis. | isoprenylated proteins bear an isoprenylcysteine methyl ester at the c terminus. although isoprenylated proteins have been implicated in meristem development and negative regulation of abscisic acid (aba) signaling, the functional role of the terminal methyl group has not been described. here, we show that transgenic arabidopsis thaliana plants overproducing isoprenylcysteine methyltransferase (icmt) exhibit aba insensitivity in stomatal closure and seed germination assays, establishing icmt as ... | 2008 | 18957507 |
| the r2r3 myb transcription factor ghmyb109 is required for cotton fiber development. | cotton (gossypium hirsutum l.) fibers are single highly elongated cells derived from the outer epidermis of ovules. a large number of genes are required for fiber differentiation and development, but so far, little is known about how these genes control and regulate the process of fiber development. here we examine the role of the cotton-fiber-specific r2r3 myb gene ghmyb109 in cotton fiber development. transgenic reporter gene analysis revealed that a 2-kb ghmyb109 promoter was sufficient to co ... | 2008 | 18780729 |
| fluorescent co-localization of pts1 and pts2 and its application in analysis of the gene function and the peroxisomal dynamic in magnaporthe oryzae. | the peroxisomal matrix proteins involved in many important biological metabolism pathways in eukaryotic cells are encoded by nucleal genes, synthesized in the cytoplasm and then transported into the organelles. targeting and import of these proteins depend on their two peroxisomal targeting signals (pts1 and pts2) in sequence as we have known so far. the vectors of the fluorescent fusions with pts, i.e., green fluorescence protein (gfp)-pts1, gfp-pts2 and red fluorescence protein (rfp)-pts1, wer ... | 2008 | 18837108 |
| discrete and essential roles of the multiple domains of arabidopsis fhy3 in mediating phytochrome a signal transduction. | phytochrome a is the primary photoreceptor for mediating various far-red light-induced responses in higher plants. we recently showed that arabidopsis (arabidopsis thaliana) far-red elongated hypocotyl3 (fhy3) and far-red-impaired response1 (far1), a pair of homologous proteins sharing significant sequence homology to mutator-like transposases, act as novel transcription factors essential for activating the expression of fhy1 and fhl (for fhy1-like), whose products are required for light-induced ... | 2008 | 18715961 |
| leafy cotyledon1 is a key regulator of fatty acid biosynthesis in arabidopsis. | in plants, fatty acids are de novo synthesized predominantly in plastids from acetyl-coenzyme a. although fatty acid biosynthesis has been biochemically well studied, little is known about the regulatory mechanisms of the pathway. here, we show that overexpression of the arabidopsis (arabidopsis thaliana) leafy cotyledon1 (lec1) gene causes globally increased expression of fatty acid biosynthetic genes, which are involved in key reactions of condensation, chain elongation, and desaturation of fa ... | 2008 | 18689444 |
| chloroplast outer envelope protein chup1 is essential for chloroplast anchorage to the plasma membrane and chloroplast movement. | chloroplasts change their intracellular distribution in response to light intensity. previously, we isolated the chloroplast unusual positioning1 (chup1) mutant of arabidopsis (arabidopsis thaliana). this mutant is defective in normal chloroplast relocation movement and shows aggregation of chloroplasts at the bottom of palisade mesophyll cells. the isolated gene encodes a protein with an actin-binding motif. here, we used biochemical analyses to determine the subcellular localization of full-le ... | 2008 | 18715957 |
| rh-pip2;1, a rose aquaporin gene, is involved in ethylene-regulated petal expansion. | aquaporins are water channel proteins that facilitate the passage of water through biological membranes and play a crucial role in plant growth. we showed that ethylene treatment significantly reduced petal size, inhibited expansion of petal abaxial subepidermal cells, and decreased petal water content in rose (rosa hybrida 'samantha'). here, we report the isolation of a plasma membrane aquaporin (pip) gene, rh-pip2;1, and characterized its potential role in ethylene-inhibited petal expansion. r ... | 2008 | 18715962 |
| generation of hydrogen peroxide in chloroplasts of arabidopsis overexpressing glycolate oxidase as an inducible system to study oxidative stress. | arabidopsis (arabidopsis thaliana) overexpressing glycolate oxidase (go) in chloroplasts accumulates both hydrogen peroxide (h(2)o(2)) and glyoxylate. go-overexpressing lines (go plants) grown at 75 micromol quanta m(-2) s(-1) show retarded development, yellowish rosettes, and impaired photosynthetic performance, while at 30 micromol quanta m(-2) s(-1), this phenotype virtually disappears. the go plants develop oxidative stress lesions under photorespiratory conditions but grow like wild-type pl ... | 2008 | 18685041 |
| mitochondrial serine acetyltransferase functions as a pacemaker of cysteine synthesis in plant cells. | cysteine (cys) synthesis in plants is carried out by two sequential reactions catalyzed by the rate-limiting enzyme serine acetyltransferase (sat) and excess amounts of o-acetylserine(thiol)lyase. why these reactions occur in plastids, mitochondria, and cytosol of plants remained unclear. expression of artificial microrna (amirna) against sat3 encoding mitochondrial sat3 in transgenic arabidopsis (arabidopsis thaliana) plants demonstrates that mitochondria are the most important compartment for ... | 2008 | 18753283 |
| two cap-binding proteins cbp20 and cbp80 are involved in processing primary micrornas. | micrornas (mirnas) are 21 nt rnas that regulate many biological processes in plants by mediating translational inhibition or cleavage of target transcripts. arabidopsis mutants defective in mirna biogenesis have overlapping and highly pleiotropic phenotypes including serrated leaves and aba hypersensitivity. recent evidence indicates that mirna genes are transcribed by rna polymerase ii (pol ii). since pol ii transcripts are capped, we hypothesized that cbp (cap-binding protein) 20 and 80 may bi ... | 2008 | 18829588 |
| cloning, characterisation and comparative analysis of a starch synthase iv gene in wheat: functional and evolutionary implications. | starch is of great importance to humans as a food and biomaterial, and the amount and structure of starch made in plants is determined in part by starch synthase (ss) activity. five ss isoforms, ssi, ii, iii, iv and granule bound ssi, have been identified, each with a unique catalytic role in starch synthesis. the basic mode of action of sss is known; however our knowledge of several aspects of ss enzymology at the structural and mechanistic level is incomplete. to gain a better understanding of ... | 2008 | 18826586 |
| stress goes far east: meeting report of the sixth international workshop on the molecular biology of stress responses. | | 2008 | 18815896 |
| stress goes far east: meeting report of the sixth international workshop on the molecular biology of stress responses. | | 2008 | 18815896 |
| regulation of root elongation by histone acetylation in arabidopsis. | transcriptional repression by histone modification represents a universal mechanism that underlies critical biological processes, such as neurogenesis and hematopoietic differentiation, in animals. in plants, however, the extent to which these regulatory pathways are involved in development and morphogenesis is not well defined. swp1/ldl1 is a component of a plant corepressor complex that is involved in regulation of flower timing. here, we report that swp1 also plays a role in the regulation of ... | 2008 | 18835563 |
| regulation of root elongation by histone acetylation in arabidopsis. | transcriptional repression by histone modification represents a universal mechanism that underlies critical biological processes, such as neurogenesis and hematopoietic differentiation, in animals. in plants, however, the extent to which these regulatory pathways are involved in development and morphogenesis is not well defined. swp1/ldl1 is a component of a plant corepressor complex that is involved in regulation of flower timing. here, we report that swp1 also plays a role in the regulation of ... | 2008 | 18835563 |
| non-cell-autonomous control of vascular stem cell fate by a cle peptide/receptor system. | land plants evolved a long-distance transport system of water and nutrients composed of the xylem and phloem, both of which are generated from the procambium- and cambium-comprising vascular stem cells. however, little is known about the molecular mechanism of cell communication governing xylem-phloem patterning. here, we show that a dodecapeptide (hevhypsghypnpisn; hyp, 4-hydroxyproline), tdif (tracheary element differentiation inhibitory factor), is secreted from the phloem and suppresses the ... | 2008 | 18812507 |
| a novel pathway of cytochrome c biogenesis is involved in the assembly of the cytochrome b6f complex in arabidopsis chloroplasts. | we recently characterized a novel heme biogenesis pathway required for heme c(i)' covalent binding to cytochrome b6 in chlamydomonas named system iv or ccb (cofactor assembly, complex c (b6f), subunit b (petb)). to find out whether this ccb pathway also operates in higher plants and extend the knowledge of the c-type cytochrome biogenesis, we studied arabidopsis insertion mutants in the orthologs of the ccb genes. the ccb1, ccb2, and ccb4 mutants show a phenotype characterized by a deficiency in ... | 2008 | 18593701 |
| experimental evidence for splicing of intron-containing transcripts of plant ltr retrotransposon ogre. | ogre elements are a distinct group of plant ty3/gypsy-like retrotransposons characterized by several specific features, one of which is a separation of the gag-pol region into two non-overlapping open reading frames: orf2 coding for gag-pro, and orf3 coding for rt/rh-int proteins. previous characterization of ogre elements from several plant species revealed that part of their transcripts lacks the region between orf2 and orf3, carrying one uninterrupted orf instead. in this work, we investigate ... | 2008 | 18762986 |
| biochemical characterization of arabidopsis complexes containing constitutively photomorphogenic1 and suppressor of phya proteins in light control of plant development. | cop1 (for constitutively photomorphogenic1) and the four partially redundant spa (for suppressor of phya) proteins work in concert to repress photomorphogenesis in arabidopsis thaliana by targeting key transcription factors and phytochrome a for degradation via the 26s proteasome. here, we report a detailed biochemical characterization of the spa-cop1 complexes. the four endogenous spa proteins can form stable complexes with cop1 in vivo regardless of light conditions but exhibit distinct expres ... | 2008 | 18812498 |
| nai2 is an endoplasmic reticulum body component that enables er body formation in arabidopsis thaliana. | plants develop various endoplasmic reticulum (er)-derived structures, each of which has specific functions. the er body found in arabidopsis thaliana is a spindle-shaped structure that specifically accumulates high levels of pyk10/bglu23, a beta-glucosidase that bears an er-retention signal. the molecular mechanisms underlying the formation of the er body remain obscure. we isolated an er body-deficient mutant in arabidopsis seedlings that we termed nai2. the nai2 gene (at3g15950) encodes a memb ... | 2008 | 18780803 |