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Sample records for arabidopsis separase functions

  1. A closed conformation of the Caenorhabditis elegans separase-securin complex.

    Science.gov (United States)

    Bachmann, Gudrun; Richards, Mark W; Winter, Anja; Beuron, Fabienne; Morris, Edward; Bayliss, Richard

    2016-04-01

    The protease separase plays a key role in sister chromatid disjunction and centriole disengagement. To maintain genomic stability, separase activity is strictly regulated by binding of an inhibitory protein, securin. Despite its central role in cell division, the separase and securin complex is poorly understood at the structural level. This is partly owing to the difficulty of generating a sufficient quantity of homogeneous, stable protein. Here, we report the production of Caenorhabditis elegans separase-securin complex, and its characterization using biochemical methods and by negative staining electron microscopy. Single particle analysis generated a density map at a resolution of 21-24 Å that reveals a close, globular structure of complex connectivity harbouring two lobes. One lobe matches closely a homology model of the N-terminal HEAT repeat domain of separase, whereas the second lobe readily accommodates homology models of the separase C-terminal death and caspase-like domains. The globular structure of the C. elegans separase-securin complex contrasts with the more elongated structure previously described for the Homo sapiens complex, which could represent a different functional state of the complex, suggesting a mechanism for the regulation of separase activity through conformational change. PMID:27249343

  2. A closed conformation of the Caenorhabditis elegans separase-securin complex.

    Science.gov (United States)

    Bachmann, Gudrun; Richards, Mark W; Winter, Anja; Beuron, Fabienne; Morris, Edward; Bayliss, Richard

    2016-04-01

    The protease separase plays a key role in sister chromatid disjunction and centriole disengagement. To maintain genomic stability, separase activity is strictly regulated by binding of an inhibitory protein, securin. Despite its central role in cell division, the separase and securin complex is poorly understood at the structural level. This is partly owing to the difficulty of generating a sufficient quantity of homogeneous, stable protein. Here, we report the production of Caenorhabditis elegans separase-securin complex, and its characterization using biochemical methods and by negative staining electron microscopy. Single particle analysis generated a density map at a resolution of 21-24 Å that reveals a close, globular structure of complex connectivity harbouring two lobes. One lobe matches closely a homology model of the N-terminal HEAT repeat domain of separase, whereas the second lobe readily accommodates homology models of the separase C-terminal death and caspase-like domains. The globular structure of the C. elegans separase-securin complex contrasts with the more elongated structure previously described for the Homo sapiens complex, which could represent a different functional state of the complex, suggesting a mechanism for the regulation of separase activity through conformational change.

  3. Synthesis and activity of benzimidazole-1,3-dioxide inhibitors of separase.

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    Do, Ha T; Zhang, Nenggang; Pati, Debananda; Gilbertson, Scott R

    2016-09-15

    Due to the oncogenic activity of cohesin protease, separase in human cancer cells, modulation of separase enzymatic activity could constitute a new therapeutic strategy for targeting resistant, separase-overexpressing aneuploid tumors. Herein, we report the synthesis, structural information, and structure-activity relationship (SAR) of separase inhibitors based on modification of the lead molecule 2,2-dimethyl-5-nitro-2H-benzimidazole-1,3-dioxide, named Sepin-1, (1) identified from a high-throughput-screen. Replacement of -NO2 at C5 with other functional groups reduce the inhibitory activity in separase enzymatic assay. Substitution of the two methyl groups with other alkyl chains at the C2 moderately improves the effects on the inhibitory activity of those compounds. Modifications on 2H-benzimidazole-1,3-dioxide or the skeleton have variable effect on inhibition of separase enzymatic activity. Density-functional theory (DFT) calculations suggest there may be a correlation between the charges on the oxide moieties on these compounds and their activity in inhibiting separase enzyme. PMID:27530289

  4. Processing, localization, and requirement of human separase for normal anaphase progression

    OpenAIRE

    Chestukhin, Anton; Pfeffer, Christian; Milligan, Scott; DeCaprio, James A.; Pellman, David

    2003-01-01

    In all eukaryotes, anaphase is triggered by the activation of a protease called separase. Once activated, separase cleaves a subunit of cohesin, a complex that links replicated chromatids before anaphase. Separase and cohesin are conserved from yeasts to humans. Although the machinery for dissolving sister cohesion is conserved, the regulation of this process appears to be more complex in higher eukaryotes than in yeast. Here we report the cloning of full-length human separase cDNA and the ch...

  5. Cut1/separase-dependent roles of multiple phosphorylation of fission yeast cohesion subunit Rad21 in post-replicative damage repair and mitosis.

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    Adachi, Yoh; Kokubu, Aya; Ebe, Masahiro; Nagao, Koji; Yanagida, Mitsuhiro

    2008-03-15

    Cohesin is a multiprotein complex essential for sister-chromatid cohesion. It plays a pivotal role in proper chromosome segregation and DNA damage repair. The mitotic behavior of cohesin is controlled through its phosphorylation, which possibly induces the dissociation of cohesin from chromosomes and enhances its susceptibility to separase. Here, we report using mass spectrometry and anti-phospho antibodies that the central domain of Rad21, the separase-target subunit of Schizosaccharomyces pombe cohesin, is regulated by various kinase-induced phosphorylation at nine residues, indicating the multiple roles for S. pombe cohesin. In vegetative and non-dividing G(0) cells, Rad21 is phosphorylated by unknown S/TP-consensus kinases, in mitotic and non-mitotic cells by polo/Plo1 and CDK, and in DNA-damaged cells by Rad3/ATR. While mitotic phosphorylation is implicated in the dissociation of Rad21 and its cleavage by separase in anaphase, the Rad3/ATR-dependent damage-induced phosphorylation occurs intensively at the time of repair completion, and only in post-replicative cells. This damage-induced Rad21 phosphorylation is involved in the recovery process of cells from checkpoint arrest, and needed for the removal of cohesin by separase after the completion of damage repair. These complex phospho-regulations of Rad21 indicate the functional significance of cohesin in cell adaptation to a variety of cellular conditions.

  6. Separase Cleaves the N-Tail of the CENP-A Related Protein CPAR-1 at the Meiosis I Metaphase-Anaphase Transition in C. elegans.

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    Joost Monen

    Full Text Available Centromeres are defined epigenetically in the majority of eukaryotes by the presence of chromatin containing the centromeric histone H3 variant CENP-A. Most species have a single gene encoding a centromeric histone variant whereas C. elegans has two: HCP-3 (also known as CeCENP-A and CPAR-1. Prior RNAi replacement experiments showed that HCP-3 is the functionally dominant isoform, consistent with CPAR-1 not being detectable in embryos. GFP::CPAR-1 is loaded onto meiotic chromosomes in diakinesis and is enriched on bivalents until meiosis I. Here we show that GFP::CPAR-1 signal loss from chromosomes precisely coincides with homolog segregation during anaphase I. This loss of GFP::CPAR-1 signal reflects proteolytic cleavage between GFP and the histone fold of CPAR-1, as CPAR-1::GFP, in which GFP is fused to the C-terminus of CPAR-1, does not exhibit any loss of GFP signal. A focused candidate screen implicated separase, the protease that initiates anaphase by cleaving the kleisin subunit of cohesin, in this cleavage reaction. Examination of the N-terminal tail sequence of CPAR-1 revealed a putative separase cleavage site and mutation of the signature residues in this site eliminated the cleavage reaction, as visualized by retention of GFP::CPAR-1 signal on separating homologous chromosomes at the metaphase-anaphase transition of meiosis I. Neither cleaved nor uncleavable CPAR-1 were centromere-localized in mitosis and instead localized throughout chromatin, indicating that centromere activity has not been retained in CPAR-1. Although the functions of CPAR-1 and of its separase-dependent cleavage remain to be elucidated, this effort reveals a new substrate of separase and provides an in vivo biosensor to monitor separase activity at the onset of meiosis I anaphase.

  7. Measurement of separase proteolytic activity in single living cells by a fluorogenic flow cytometry assay.

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    Wiltrud Haaß

    Full Text Available ESPL1/Separase, an endopeptidase, is required for centrosome duplication and separation of sister-chromatides in anaphase of mitosis. Overexpression and deregulated proteolytic activity of Separase as frequently observed in human cancers is associated with the occurrence of supernumerary centrosomes, chromosomal missegregation and aneuploidy. Recently, we have hypothesized that increased Separase proteolytic activity in a small subpopulation of tumor cells may serve as driver of tumor heterogeneity and clonal evolution in chronic myeloid leukemia (CML. Currently, there is no quantitative assay to measure Separase activity levels in single cells. Therefore, we have designed a flow cytometry-based assay that utilizes a Cy5- and rhodamine 110 (Rh110-biconjugated Rad21 cleavage site peptide ([Cy5-D-R-E-I-M-R]2-Rh110 as smart probe and intracellular substrate for detection of Separase enzyme activity in living cells. As measured by Cy5 fluorescence the cellular uptake of the fluorogenic peptide was fast and reached saturation after 210 min of incubation in human histiocytic lymphoma U937 cells. Separase activity was recorded as the intensity of Rh110 fluorescence released after intracellular peptide cleavage providing a linear signal gain within a 90-180 min time slot. Compared to conventional cell extract-based methods the flow cytometric assay delivers equivalent results but is more reliable, bypasses the problem of vague loading controls and unspecific proteolysis associated with whole cell extracts. Especially suited for the investigaton of blood- and bone marrow-derived hematopoietic cells the flow cytometric Separase assay allows generation of Separase activity profiles that tell about the number of Separase positive cells within a sample i.e. cells that currently progress through mitosis and about the range of intercellular variation in Separase activity levels within a cell population. The assay was used to quantify Separase proteolytic

  8. Functional Analysis of Arabidopsis Sucrose Transporters

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    John M. Ward

    2009-03-31

    Sucrose is the main photosynthetic product that is transported in the vasculature of plants. The long-distance transport of carbohydrates is required to support the growth and development of net-importing (sink) tissues such as fruit, seeds and roots. This project is focused on understanding the transport mechanism sucrose transporters (SUTs). These are proton-coupled sucrose uptake transporters (membrane proteins) that are required for transport of sucrose in the vasculature and uptake into sink tissues. The accomplishments of this project included: 1) the first analysis of substrate specificity for any SUT. This was accomplished using electrophysiology to analyze AtSUC2, a sucrose transporter from companion cells in Arabidopsis. 2) the first analysis of the transport activity for a monocot SUT. The transport kinetics and substrate specificity of HvSUT1 from barley were studied. 3) the first analysis of a sucrose transporter from sugarcane. and 4) the first analysis of transport activity of a sugar alcohol transporter homolog from plants, AtPLT5. During this period four primary research papers, funded directly by the project, were published in refereed journals. The characterization of several sucrose transporters was essential for the current effort in the analysis of structure/function for this gene family. In particular, the demonstration of strong differences in substrate specificity between type I and II SUTs was important to identify targets for site-directed mutagenesis.

  9. Separase phosphosite mutation leads to genome instability and primordial germ cell depletion during oogenesis.

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    Juan Xu

    Full Text Available To ensure equal chromosome segregation and the stability of the genome during cell division, Separase is strictly regulated primarily by Securin binding and inhibitory phosphorylation. By generating a mouse model that contained a mutation to the inhibitory phosphosite of Separase, we demonstrated that mice of both sexes are infertile. We showed that Separase deregulation leads to chromosome mis-segregation, genome instability, and eventually apoptosis of primordial germ cells (PGCs during embryonic oogenesis. Although the PGCs of mutant male mice were completely depleted, a population of PGCs from mutant females survived Separase deregulation. The surviving PGCs completed oogenesis but produced deficient initial follicles. These results indicate a sexual dimorphism effect on PGCs from Separase deregulation, which may be correlated with a gender-specific discrepancy of Securin. Our results reveal that Separase phospho-regulation is critical for genome stability in oogenesis. Furthermore, we provided the first evidence of a pre-zygotic mitotic chromosome segregation error resulting from Separase deregulation, whose sex-specific differences may be a reason for the sexual dimorphism of aneuploidy in gametogenesis.

  10. Gene Discovery and Functional Analyses in the Model Plant Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Cai-Ping Feng; John Mundy

    2006-01-01

    The present mini-review describes newer methods and strategies, including transposon and T-DNA insertions,TILLING, Deleteagene, and RNA interference, to functionally analyze genes of interest in the model plant Arabidopsis. The relative advantages and disadvantages of the systems are also discussed.

  11. Gene Discovery and Functional Analyses in the Model Plant Arabidopsis

    DEFF Research Database (Denmark)

    Feng, Cai-ping; Mundy, J.

    2006-01-01

    The present mini-review describes newer methods and strategies, including transposon and T-DNA insertions, TILLING, Deleteagene, and RNA interference, to functionally analyze genes of interest in the model plant Arabidopsis. The relative advantages and disadvantages of the systems are also...

  12. Glutamate functions in stomatal closure in Arabidopsis and fava bean.

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    Yoshida, Riichiro; Mori, Izumi C; Kamizono, Nobuto; Shichiri, Yudai; Shimatani, Tetsuo; Miyata, Fumika; Honda, Kenji; Iwai, Sumio

    2016-01-01

    Guard cells are indispensable for higher plants because they control gas exchange and water balance to maintain photosynthetic activity. The signaling processes that govern their movement are controlled by several factors, such as abscisic acid (ABA), blue light, pathogen-associated molecular patterns (PAMPs), and carbon dioxide. Herein, we demonstrated that the amino acid glutamate (Glu), a well-known mammalian neurotransmitter, functions as a novel signaling molecule in stomatal closure in both Arabidopsis and fava bean (Vicia faba L.). Pharmacological and electrophysiological analyses provided important clues for the participation of Glu-receptors, Ca(2+), and protein phosphorylation during the signaling process. Genetic analyses using Arabidopsis ABA-deficient (aba2-1) and ABA-insensitive (abi1-1 and abi2-1) mutants showed that ABA is not required for Glu signaling. However, loss-of-function of the Arabidopsis gene encoding Slow Anion Channel-Associated 1 (SLAC1) and Calcium-Dependent Protein Kinase 6 (CPK6) impaired the Glu response. Moreover, T-DNA knockout mutations of the Arabidopsis Glu receptor-like gene (GLR), GLR3.5, lost their sensitivity to Glu-dependent stomatal closure. Our results strongly support functional Glu-signaling in stomatal closure and the crucial roles of GLRs in this signaling process. PMID:26586261

  13. A Genetic Pathway for Tapetum Development and Function in Arabidopsis

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    Jun Zhu; Yue Lou; Xiaofeng Xu; Zhong-Nan Yang

    2011-01-01

    In anther development,tapetal cells take part in complex processes,including endomitosis and apoptosis (programmed cell death).The tapetum provides many of the proteins,lipids,polysaccharides and other molecules necessary for pollen development.Several transcription factors,including DYT1,TDF1,AMS,MS188 and MS1,have been reported to be essential for tapetum development and function in Arabidopsis thaliana.Here,we present a detailed cytological analysis of knockout mutants for these genes,along with an in situ RNA hybridization experiment and double mutant analysis showing that these transcription factors form a genetic pathway in tapetum development.DYT1,TDF1 and AMS function in early tapetum development,while MS188 and MS1 are important for late tapetum development.The genetic pathway revealed in this work facilitates further investigation of the function and molecular mechanisms of tapetum development in Arabidopsis.

  14. Developmentally distinct MYB genes encode functionally equivalent proteins in Arabidopsis.

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    Lee, M M; Schiefelbein, J

    2001-05-01

    The duplication and divergence of developmental control genes is thought to have driven morphological diversification during the evolution of multicellular organisms. To examine the molecular basis of this process, we analyzed the functional relationship between two paralogous MYB transcription factor genes, WEREWOLF (WER) and GLABROUS1 (GL1), in Arabidopsis. The WER and GL1 genes specify distinct cell types and exhibit non-overlapping expression patterns during Arabidopsis development. Nevertheless, reciprocal complementation experiments with a series of gene fusions showed that WER and GL1 encode functionally equivalent proteins, and their unique roles in plant development are entirely due to differences in their cis-regulatory sequences. Similar experiments with a distantly related MYB gene (MYB2) showed that its product cannot functionally substitute for WER or GL1. Furthermore, an analysis of the WER and GL1 proteins shows that conserved sequences correspond to specific functional domains. These results provide new insights into the evolution of the MYB gene family in Arabidopsis, and, more generally, they demonstrate that novel developmental gene function may arise solely by the modification of cis-regulatory sequences.

  15. Composition and function of P bodies in Arabidopsis thaliana

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    Luis David Maldonado-Bonilla

    2014-05-01

    Full Text Available mRNA accumulation is tightly regulated by diverse molecular pathways. The identification and characterization of enzymes and regulatory proteins involved in controlling the fate of mRNA offers the possibility to broaden our understanding of posttranscriptional gene regulation. Processing bodies (P bodies, PB are cytoplasmic protein complexes involved in degradation and translational arrest of mRNA. Composition and dynamics of these subcellular structures have been studied in animal systems, yeasts and in the model plant Arabidopsis. Their assembly implies the aggregation of specific factors related to decapping, deadenylation and exoribonucleases that operate synchronously to regulate certain mRNA targets during development and adaptation to stress. Although the general function of PB along with the flow of genetic information is understood, several questions still remain open. This review summarizes data on the composition, potential molecular roles, and biological significance of PB and potentially related proteins in Arabidopsis.

  16. Positive feedback promotes mitotic exit via the APC/C-Cdh1-separase-Cdc14 axis in budding yeast.

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    Hatano, Yuhki; Naoki, Koike; Suzuki, Asuka; Ushimaru, Takashi

    2016-10-01

    The mitotic inhibitor securin is degraded via the ubiquitin ligase anaphase-promoting complex/cyclosome (APC/C)-Cdc20 after anaphase onset. This triggers activation of the mitotic protease separase and thereby sister chromatid separation. However, only a proportion of securin molecules are degraded at metaphase-anaphase transition and the remaining molecules are still present in anaphase. The roles of securin and separase in late mitosis remain elusive. Here, we show that securin still inhibits separase to repress mitotic exit in anaphase in budding yeast. APC/C-Cdh1-mediated securin degradation at telophase further liberated separase, which promotes Cdc14 release and mitotic exit. Separase executed these events via its proteolytic action and that in the Cdc14 early release (FEAR) network. Cdc14 release further activated APC/C-Cdh1 in the manner of a positive feedback loop. Thus, the positive feedback promotes mitotic exit via the APC/C-Cdh1-separase-Cdc14 axis. This study shows the importance of the two-step degradation mode of securin and the role of separase in mitotic exit.

  17. Positive feedback promotes mitotic exit via the APC/C-Cdh1-separase-Cdc14 axis in budding yeast.

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    Hatano, Yuhki; Naoki, Koike; Suzuki, Asuka; Ushimaru, Takashi

    2016-10-01

    The mitotic inhibitor securin is degraded via the ubiquitin ligase anaphase-promoting complex/cyclosome (APC/C)-Cdc20 after anaphase onset. This triggers activation of the mitotic protease separase and thereby sister chromatid separation. However, only a proportion of securin molecules are degraded at metaphase-anaphase transition and the remaining molecules are still present in anaphase. The roles of securin and separase in late mitosis remain elusive. Here, we show that securin still inhibits separase to repress mitotic exit in anaphase in budding yeast. APC/C-Cdh1-mediated securin degradation at telophase further liberated separase, which promotes Cdc14 release and mitotic exit. Separase executed these events via its proteolytic action and that in the Cdc14 early release (FEAR) network. Cdc14 release further activated APC/C-Cdh1 in the manner of a positive feedback loop. Thus, the positive feedback promotes mitotic exit via the APC/C-Cdh1-separase-Cdc14 axis. This study shows the importance of the two-step degradation mode of securin and the role of separase in mitotic exit. PMID:27418100

  18. Arabidopsis gene co-expression network and its functional modules

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    Dash Sudhansu

    2009-10-01

    Full Text Available Abstract Background Biological networks characterize the interactions of biomolecules at a systems-level. One important property of biological networks is the modular structure, in which nodes are densely connected with each other, but between which there are only sparse connections. In this report, we attempted to find the relationship between the network topology and formation of modular structure by comparing gene co-expression networks with random networks. The organization of gene functional modules was also investigated. Results We constructed a genome-wide Arabidopsis gene co-expression network (AGCN by using 1094 microarrays. We then analyzed the topological properties of AGCN and partitioned the network into modules by using an efficient graph clustering algorithm. In the AGCN, 382 hub genes formed a clique, and they were densely connected only to a small subset of the network. At the module level, the network clustering results provide a systems-level understanding of the gene modules that coordinate multiple biological processes to carry out specific biological functions. For instance, the photosynthesis module in AGCN involves a very large number (> 1000 of genes which participate in various biological processes including photosynthesis, electron transport, pigment metabolism, chloroplast organization and biogenesis, cofactor metabolism, protein biosynthesis, and vitamin metabolism. The cell cycle module orchestrated the coordinated expression of hundreds of genes involved in cell cycle, DNA metabolism, and cytoskeleton organization and biogenesis. We also compared the AGCN constructed in this study with a graphical Gaussian model (GGM based Arabidopsis gene network. The photosynthesis, protein biosynthesis, and cell cycle modules identified from the GGM network had much smaller module sizes compared with the modules found in the AGCN, respectively. Conclusion This study reveals new insight into the topological properties of

  19. A Mitochondrial Magnesium Transporter Functions in Arabidopsis Pollen Development

    Institute of Scientific and Technical Information of China (English)

    Le-Gong Li; Lubomir N.Sokolov; Yong-Hua Yang; Dong-Ping Li; Julie Ting; Girdhar K.Pandy; Sheng Luan

    2008-01-01

    Magnesium is an abundant divalent cation in plant cells and plays a critical role in many physiological processes.We have previously described the jdentification of a 10-member Arabidopsis gene family encoding putative magnesium transport(MGT)proteins.Here,we report that a member of the MGT family,AtMGT5, functions as a dual-functional Mg-transporter that operates in a concentration-dependent manner, namely it serves as a Mg-importer at micromolar levels and facilitates the efflux in the millimolar range.The AtMGT5 protein is localized in the mitochondria,suggesting that AtMGT5 mediates Mg-trafficking between the cytosol and mitochondria.The AtMGT5 gene was exclusively expressed in anthers at early stages of flower development.Examination of two independent T-DNA insertional mutants of AtMGT5 gene demonstrated that AtMG7-5 played an essential role for pollen development and male fertility.This study suggests a critical role for Mg2+ transport between cytosol and mitochondria in male gametogenesis in plants.

  20. Arabidopsis thaliana mTERF proteins: evolution and functional classification

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    Tatjana eKleine

    2012-10-01

    Full Text Available Organellar gene expression (OGE is crucial for plant development, photosynthesis and respiration, but our understanding of the mechanisms that control it is still relatively poor. Thus, OGE requires various nucleus-encoded proteins that promote transcription, splicing, trimming and editing of organellar RNAs, and regulate translation. In metazoans, proteins of the mitochondrial Transcription tERmination Factor (mTERF family interact with the mitochondrial chromosome and regulate transcriptional initiation and termination. Sequencing of the Arabidopsis thaliana genome led to the identification of a diversified MTERF gene family but, in contrast to mammalian mTERFs, knowledge about the function of these proteins in photosynthetic organisms is scarce. In this hypothesis article, I show that tandem duplications and one block duplication contributed to the large number of MTERF genes in A. thaliana, and propose that the expansion of the family is related to the evolution of land plants. The MTERF genes - especially the duplicated genes - display a number of distinct mRNA accumulation patterns, suggesting functional diversification of mTERF proteins to increase adaptability to environmental changes. Indeed, hypothetical functions for the different mTERF proteins can be predicted using co-expression analysis and gene ontology annotations. On this basis, mTERF proteins can be sorted into five groups. Members of the chloroplast and chloroplast-associated clusters are principally involved in chloroplast gene expression, embryogenesis and protein catabolism, while representatives of the mitochondrial cluster seem to participate in DNA and RNA metabolism in that organelle. Moreover, members of the mitochondrion-associated cluster and the low expression group may act in the nucleus and/or the cytosol. As proteins involved in OGE and presumably nuclear gene expression, mTERFs are ideal candidates for the coordination of the expression of organelle and nuclear

  1. Different subcellular localizations and functions of Arabidopsis myosin VIII

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    Belausov Eduard

    2008-01-01

    Full Text Available Abstract Background Myosins are actin-activated ATPases that use energy to generate force and move along actin filaments, dragging with their tails different cargos. Plant myosins belong to the group of unconventional myosins and Arabidopsis myosin VIII gene family contains four members: ATM1, ATM2, myosin VIIIA and myosin VIIIB. Results In transgenic plants expressing GFP fusions with ATM1 (IQ-tail truncation, lacking the head domain, fluorescence was differentially distributed: while in epidermis cells at the root cap GFP-ATM1 equally distributed all over the cell, in epidermal cells right above this region it accumulated in dots. Further up, in cells of the elongation zone, GFP-ATM1 was preferentially positioned at the sides of transversal cell walls. Interestingly, the punctate pattern was insensitive to brefeldin A (BFA while in some cells closer to the root cap, ATM1 was found in BFA bodies. With the use of different markers and transient expression in Nicotiana benthamiana leaves, it was found that myosin VIII co-localized to the plasmodesmata and ER, colocalized with internalized FM4-64, and partially overlapped with the endosomal markers ARA6, and rarely with ARA7 and FYVE. Motility of ARA6 labeled organelles was inhibited whenever associated with truncated ATM1 but motility of FYVE labeled organelles was inhibited only when associated with large excess of ATM1. Furthermore, GFP-ATM1 and RFP-ATM2 (IQ-tail domain co-localized to the same spots on the plasma membrane, indicating a specific composition at these sites for myosin binding. Conclusion Taken together, our data suggest that myosin VIII functions differently in different root cells and can be involved in different steps of endocytosis, BFA-sensitive and insensitive pathways, ER tethering and plasmodesmatal activity.

  2. Evolutionary Fates and Dynamic Functionalization of Young Duplicate Genes in Arabidopsis Genomes1[OPEN

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    Wang, Jun; Tao, Feng; Marowsky, Nicholas C.; Fan, Chuanzhu

    2016-01-01

    Gene duplication is a primary means to generate genomic novelties, playing an essential role in speciation and adaptation. Particularly in plants, a high abundance of duplicate genes has been maintained for significantly long periods of evolutionary time. To address the manner in which young duplicate genes were derived primarily from small-scale gene duplication and preserved in plant genomes and to determine the underlying driving mechanisms, we generated transcriptomes to produce the expression profiles of five tissues in Arabidopsis thaliana and the closely related species Arabidopsis lyrata and Capsella rubella. Based on the quantitative analysis metrics, we investigated the evolutionary processes of young duplicate genes in Arabidopsis. We determined that conservation, neofunctionalization, and specialization are three main evolutionary processes for Arabidopsis young duplicate genes. We explicitly demonstrated the dynamic functionalization of duplicate genes along the evolutionary time scale. Upon origination, duplicates tend to maintain their ancestral functions; but as they survive longer, they might be likely to develop distinct and novel functions. The temporal evolutionary processes and functionalization of plant duplicate genes are associated with their ancestral functions, dynamic DNA methylation levels, and histone modification abundances. Furthermore, duplicate genes tend to be initially expressed in pollen and then to gain more interaction partners over time. Altogether, our study provides novel insights into the dynamic retention processes of young duplicate genes in plant genomes. PMID:27485883

  3. Evolutionary Fates and Dynamic Functionalization of Young Duplicate Genes in Arabidopsis Genomes.

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    Wang, Jun; Tao, Feng; Marowsky, Nicholas C; Fan, Chuanzhu

    2016-09-01

    Gene duplication is a primary means to generate genomic novelties, playing an essential role in speciation and adaptation. Particularly in plants, a high abundance of duplicate genes has been maintained for significantly long periods of evolutionary time. To address the manner in which young duplicate genes were derived primarily from small-scale gene duplication and preserved in plant genomes and to determine the underlying driving mechanisms, we generated transcriptomes to produce the expression profiles of five tissues in Arabidopsis thaliana and the closely related species Arabidopsis lyrata and Capsella rubella Based on the quantitative analysis metrics, we investigated the evolutionary processes of young duplicate genes in Arabidopsis. We determined that conservation, neofunctionalization, and specialization are three main evolutionary processes for Arabidopsis young duplicate genes. We explicitly demonstrated the dynamic functionalization of duplicate genes along the evolutionary time scale. Upon origination, duplicates tend to maintain their ancestral functions; but as they survive longer, they might be likely to develop distinct and novel functions. The temporal evolutionary processes and functionalization of plant duplicate genes are associated with their ancestral functions, dynamic DNA methylation levels, and histone modification abundances. Furthermore, duplicate genes tend to be initially expressed in pollen and then to gain more interaction partners over time. Altogether, our study provides novel insights into the dynamic retention processes of young duplicate genes in plant genomes. PMID:27485883

  4. Functional analysis of jasmonate-responsive transcription factors in Arabidopsis thaliana

    NARCIS (Netherlands)

    Zarei, Adel

    2007-01-01

    The aim of the studies described in this thesis was the functional analysis of JA-responsive transcription factors in Arabidopsis with an emphasis on the interaction with the promoters of their target genes. In short, the following new results were obtained. The promoter of the PDF1.2 gene contains

  5. Functional analysis of the theobroma cacao NPR1 gene in arabidopsis

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    Verica Joseph

    2010-11-01

    Full Text Available Abstract Background The Arabidopsis thaliana NPR1 gene encodes a transcription coactivator (NPR1 that plays a major role in the mechanisms regulating plant defense response. After pathogen infection and in response to salicylic acid (SA accumulation, NPR1 translocates from the cytoplasm into the nucleus where it interacts with other transcription factors resulting in increased expression of over 2000 plant defense genes contributing to a pathogen resistance response. Results A putative Theobroma cacao NPR1 cDNA was isolated by RT-PCR using degenerate primers based on homologous sequences from Brassica, Arabidopsis and Carica papaya. The cDNA was used to isolate a genomic clone from Theobroma cacao containing a putative TcNPR1 gene. DNA sequencing revealed the presence of a 4.5 kb coding region containing three introns and encoding a polypeptide of 591 amino acids. The predicted TcNPR1 protein shares 55% identity and 78% similarity to Arabidopsis NPR1, and contains each of the highly conserved functional domains indicative of this class of transcription factors (BTB/POZ and ankyrin repeat protein-protein interaction domains and a nuclear localization sequence (NLS. To functionally define the TcNPR1 gene, we transferred TcNPR1 into an Arabidopsis npr1 mutant that is highly susceptible to infection by the plant pathogen Pseudomonas syringae pv. tomato DC3000. Driven by the constitutive CaMV35S promoter, the cacao TcNPR1 gene partially complemented the npr1 mutation in transgenic Arabidopsis plants, resulting in 100 fold less bacterial growth in a leaf infection assay. Upon induction with SA, TcNPR1 was shown to translocate into the nucleus of leaf and root cells in a manner identical to Arabidopsis NPR1. Cacao NPR1 was also capable of participating in SA-JA signaling crosstalk, as evidenced by the suppression of JA responsive gene expression in TcNPR1 overexpressing transgenic plants. Conclusion Our data indicate that the TcNPR1 is a functional

  6. Defining the Functional Network of Epigenetic Regulators in Arabidopsis thaliana

    Institute of Scientific and Technical Information of China (English)

    Chongyuan Luo; Brittany G.Durgin; Naohide Watanabe; Eric Lam

    2009-01-01

    Development of ChiP-chip and ChlP-seq technologies has allowed genome-wide high-resolution profiling of chromatin-associated marks and binding sites for epigenetic regulators.However,signals for directing epigenetic modi fiers to their target sites are not understood.In this paper,we tested the hypothesis that genome location can affect the involvement of epigenetic regulators using Chromatin Charting (CC) Lines,which have an identical transgene construct inserted at different locations in the Arabidopsis genome.Four CC lines that showed evidence for epigenetic silencing of the luciferase reporter gene were transformed with RNAi vectors individually targeting epigenetic regulators LHP1,MOM1,CMT3,DRD1,DRM2,SUVH2,CLF,and HD1.Involvement of a particular epigenetic regulator in silencing the transgene locus in a CC line was determined by significant alterations in luciferase expression after suppression of the regulator's expression.Our results suggest that the targeting of epigenetic regulators can be influenced by genome location as well as sequence context.In addition,the relative importance of an epigenetic regulator can be influenced by tissue identity.We also report a novel approach to predict interactions between epigenetic regulators through clustering analysis of the regulators using alterations in gene expression of putative downstream targets,including endogenous loci and transgenes,in epigenetic mutants or RNAi lines.Our data support the existence of a complex and dynamic network of epigenetic regulators that serves to coordinate and control global gene expression in higher plants.

  7. Separase Is Required for Homolog and Sister Disjunction during Drosophila melanogaster Male Meiosis, but Not for Biorientation of Sister Centromeres.

    OpenAIRE

    Blattner, Ariane C.; Soumya Chaurasia; McKee, Bruce D.; Lehner, Christian F.

    2016-01-01

    Spatially controlled release of sister chromatid cohesion during progression through the meiotic divisions is of paramount importance for error-free chromosome segregation during meiosis. Cohesion is mediated by the cohesin protein complex and cleavage of one of its subunits by the endoprotease separase removes cohesin first from chromosome arms during exit from meiosis I and later from the pericentromeric region during exit from meiosis II. At the onset of the meiotic divisions, cohesin has ...

  8. Identification of functional domains in Arabidopsis thaliana mRNA decapping enzyme (AtDcp2)

    OpenAIRE

    Gunawardana, Dilantha; Cheng, Heung-Chin; Gayler, Kenwyn R.

    2007-01-01

    The Arabidopsis thaliana decapping enzyme (AtDcp2) was characterized by bioinformatics analysis and by biochemical studies of the enzyme and mutants produced by recombinant expression. Three functionally significant regions were detected: (i) a highly disordered C-terminal region with a putative PSD-95, Discs-large, ZO-1 (PDZ) domain-binding motif, (ii) a conserved Nudix box constituting the putative active site and (iii) a putative RNA binding domain consisting of the conserved Box B and a p...

  9. Functional interconnection of MYC2 and SPA1 in the photomorphogenic seedling development of Arabidopsis.

    Science.gov (United States)

    Gangappa, Sreeramaiah N; Prasad, V Babu Rajendra; Chattopadhyay, Sudip

    2010-11-01

    MYC2 is a basic helix-loop-helix transcription factor that cross talks with light, abscisic acid (ABA), and jasmonic acid (JA) signaling pathways. Here, we have shown that Arabidopsis (Arabidopsis thaliana) MYC2 directly binds to the G-box present in the SUPPRESSOR OF PHYTOCHROME A1 (SPA1) promoter and that it controls the expression of SPA1 in a COP1-dependent manner. Analyses of atmyc2 spa1 double mutants suggest that whereas MYC2 and SPA1 act redundantly to suppress photomorphogenic growth in the dark, they function synergistically for the suppression of photomorphogenic growth in the light. Our studies have also revealed that MYC2-mediated ABA and JA responses are further modulated by SPA1. Taken together, this study demonstrates the molecular and physiological interrelations of MYC2 and SPA1 in light, ABA, and JA signaling pathways.

  10. Characterization and pilot functional study of a rootspecific MYB transcription factor of Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    An MYB transcription factor (AtMYB305) ofArabidopsis was structurally characterized. The biochemical activity of the protein was tested and its in vivo function was preliminarily analyzed. AtMYB305 contains two imperfect repeats (R2, R3) in its DNA binding domain. Gel mobility shift assay demonstrated that GST-AtMYB305 fusion protein bound specifically to the DNA fragment that included a consensus MYB recognition sequence (TAACTG). Overexpression of AtMYB305 in the fission yeast caused the formation of elongated cells with one condensed nucleus.Semi-quantitative RT-PCR analysis revealed that AtMYB305was expressed specifically in the roots of Arabidopsis.

  11. In Vivo Phosphorylation Site Mapping and Functional Characterization of Arabidopsis Phototropin 1

    Institute of Scientific and Technical Information of China (English)

    Stuart Sullivan; Catriona E. Thomson; Douglas J.Lamont; Matthew A. Jones; John M.Christie

    2008-01-01

    Phototropins (phot1 and phot2) are blue-light receptor kinases controlling a range of responses that optimize the photosynthetic efficiency of plants. Light sensing is mediated by two flavin-binding motifs, known as LOV1 and LOV2,located within the N-terminal region of the protein. Photoexcitation via LOV2 leads to activation of the C-terminal kinase domain and consequently receptor autophosphorylation. However, knowledge of the in-vivo phosphorylation sites for Arabidopsis phototropins is lacking and has impeded progress in elucidating the functional significance of receptor phosphorylation. We have purified phot1 from Arabidopsis and identified the in-vivo sites of receptor phosphorylation by liquid chromatography tandem mass spectrometry. Arabidopsis-derived phot1 binds flavin mononucleotide as chromophore and is phosphorylated at four major sites located upstream of LOV2 (Ser58, Ser85, Ser350, and Ser410), three of which are induced by blue light. Nevertheless, structure-function analysis indicates that the biological activity of phot1 can be attributed to a modular unit comprising the LOV2-kinase region of the protein. Thus, peptide regions upstream of LOV2, including the sites of receptor phosphorylation identified here, do not appear to be important for receptor signaling. By contrast, these regions may be necessary for maximizing stomatal performance and possibly light-induced relocalization of phot1.

  12. Proteomic analysis of the Arabidopsis nucleolus suggests novel nucleolar functions

    DEFF Research Database (Denmark)

    Pendle, Alison F; Clark, Gillian P; Boon, Reinier;

    2005-01-01

    The eukaryotic nucleolus is involved in ribosome biogenesis and a wide range of other RNA metabolism and cellular functions. An important step in the functional analysis of the nucleolus is to determine the complement of proteins of this nuclear compartment. Here, we describe the first proteomic...

  13. Arabinogalactan proteins 6 and 11 are required for stamen and pollen function in Arabidopsis.

    Science.gov (United States)

    Levitin, Bella; Richter, Dganit; Markovich, Inbal; Zik, Moriyah

    2008-11-01

    Successful male reproductive function in plants is dependent on the correct development and functioning of stamens and pollen. AGP6 and AGP11 are two homologous Arabidopsis genes encoding cell wall-associated arabinogalactan glycoproteins (AGPs). Both genes were found to be specifically expressed in stamens, pollen grains and pollen tubes, suggesting that these genes may play a role in male organ development and function. RNAi lines with reduced AGP6 and AGP11 expression were generated. These, together with lines harboring point mutations in the coding region of AGP6, were used to show that loss of function in AGP6 and AGP11 led to reduced fertility, at least partly as a result of inhibition of pollen tube growth. Our results also suggest that AGP6 and AGP11 play an additional role in the release of pollen grains from the mature anther. Thus, our study demonstrates the involvement of specific AGPs in pollen tube growth and stamen function.

  14. Conserved Functions of Arabidopsis and Rice CC-Type Glutaredoxins in Flower Development and Pathogen Response

    Institute of Scientific and Technical Information of China (English)

    Zhen Wang; Shuping Xing; Rainer P. Birkenbihl; Sabine Zachgo

    2009-01-01

    Glutaredoxins (GRXs) are ubiquitous oxidoreductases that play a crucial role in response to oxidative stress by reducing disulfides in various organisms. In planta, three different GRX classes have been identified according to their active site motifs. CPYC and CGFS classes are found in all organisms, whereas the CC-type class is specific for higher land plants. Recently, two Arabidopsis CC-type GRXs, ROXY1 and ROXY2, were shown to exert crucial functions in petal and anther initiation and differentiation. To analyze the function of CC-type GRXs in the distantly related monocots, we iso-lated and characterized OsROXY1 and OsROXY2-two rice homologs of ROXY1. Both genes are expressed in vegetative and reproductive stages. Although rice flower morphology is distinct from eudicots, OsROXY1/2 floral expression patterns are similar to their Arabidopsis counterparts ROXY1/2. Complementation experiments demonstrate that OsROXY1 and OsROXY2 can fully rescue the roxy1 floral mutant phenotype. Overexpression of OsROXY1, OsROXY2, and ROXY1 in Ara-bidopsis causes similar vegetative and reproductive plant developmental defects. ROXY1 and its rice homologs thus exert a conserved function during eudicot and monocot flower development. Strikingly, overexpression of these CC-type GRXs also leads to an increased accumulation of hydrogen peroxide levels and hyper-susceptibility to infection from the necrotrophic pathogen Botrytis cinerea, revealing the importance of balanced redox processes in flower organ develop-ment and pathogen defence.

  15. Functional Analysis of Cellulose and Xyloglucan in the Walls of Stomatal Guard Cells of Arabidopsis.

    Science.gov (United States)

    Rui, Yue; Anderson, Charles T

    2016-03-01

    Stomatal guard cells are pairs of specialized epidermal cells that control water and CO2 exchange between the plant and the environment. To fulfill the functions of stomatal opening and closure that are driven by changes in turgor pressure, guard cell walls must be both strong and flexible, but how the structure and dynamics of guard cell walls enable stomatal function remains poorly understood. To address this question, we applied cell biological and genetic analyses to investigate guard cell walls and their relationship to stomatal function in Arabidopsis (Arabidopsis thaliana). Using live-cell spinning disk confocal microscopy, we measured the motility of cellulose synthase (CESA)-containing complexes labeled by green fluorescent protein (GFP)-CESA3 and observed a reduced proportion of GFP-CESA3 particles colocalizing with microtubules upon stomatal closure. Imaging cellulose organization in guard cells revealed a relatively uniform distribution of cellulose in the open state and a more fibrillar pattern in the closed state, indicating that cellulose microfibrils undergo dynamic reorganization during stomatal movements. In cesa3(je5) mutants defective in cellulose synthesis and xxt1 xxt2 mutants lacking the hemicellulose xyloglucan, stomatal apertures, changes in guard cell length, and cellulose reorganization were aberrant during fusicoccin-induced stomatal opening or abscisic acid-induced stomatal closure, indicating that sufficient cellulose and xyloglucan are required for normal guard cell dynamics. Together, these results provide new insights into how guard cell walls allow stomata to function as responsive mediators of gas exchange at the plant surface. PMID:26729799

  16. A bioinformatics approach to investigate the function of non specific lipid transfer proteins in Arabidopsis thaliana

    OpenAIRE

    Jayachandra Pandiyan, Muneeswaran

    2010-01-01

    Plant non specific lipid transfer proteins (nsLTPs) enhance in vitro transfer of phospholipids between membranes. Our analysis exploited the large amount of Arabidopsis transcriptome data in public databases to learn more about the function of nsLTPs. The analysis revealed that some nsLTPs are expressed only in roots, some are seed specific, and others are specific for tissues above ground whereas certain nsLTPs show a more general expression pattern. Only few nsLTPs showed a strong up or dow...

  17. Final Report [Function of the Arabidopsis TIR1 gene in auxin response

    Energy Technology Data Exchange (ETDEWEB)

    Estelle, Mark

    2000-12-18

    During this grant period substantial progress was made in the characterization of the TIR1 gene in Arabidopsis. Studies showed that the TIR1 protein is part of a protein complex that includes AtCUL1, ASK1 and RBX1. This complex, called SCF-TIR1, functions in the ubiquitin-mediated protein degradation pathway. Our work is the first report of an SCF complex in a plant system. The results of our studies are described in more detail in the report together with a publication resulting from this study.

  18. Construction of a chloroplast protein interaction network and functional mining of photosynthetic proteins in Arabidopsis thaliana

    Institute of Scientific and Technical Information of China (English)

    Qing-Bo Yu; Yong-Lan Cui; Kang Chong; Yi-Xue Li; Yu-Hua Li; Zhongming Zhao; Tie-Liu Shi; Zhong-Nan Yang; Guang Li; Guan Wang; Jing-Chun Sun; Peng-Cheng Wang; Chen Wang; Hua-Ling Mi; Wei-Min Ma; Jian Cui

    2008-01-01

    Chloroplast is a typical plant cell organeUe where photosynthesis takes place.In this study,a total of 1 808 chloroplast core proteins in Arabidopsis thaliana were reliably identified by combining the results of previously published studies and our own predictions.We then constructed a chloroplast protein interaction network primarily based on these core protein interactions.The network had 22 925 protein interaction pairs which involved 2 214 proteins.A total of 160 previously uncharacterized proteins were annotated in this network.The subunits of the photosynthetic complexes were modularized,and the functional relationships among photosystem Ⅰ (PSI),photosystem Ⅱ (PSII),light harvesting complex of photosystem Ⅰ (LHC Ⅰ) and light harvesting complex of photosystem Ⅰ (LHC Ⅱ) could be deduced from the predicted protein interactions in this network.We further confirmed an interaction between an unknown protein AT1G52220 and a photosynthetic subunit PSI-D2 by yeast two-hybrid analysis.Our chloroplast protein interaction network should be useful for functional mining of photosynthetic proteins and investigation of chloroplast-related functions at the systems biology level in Arabidopsis.

  19. A Genome-Scale Resource for the Functional Characterization of Arabidopsis Transcription Factors

    Directory of Open Access Journals (Sweden)

    Jose L. Pruneda-Paz

    2014-07-01

    Full Text Available Extensive transcriptional networks play major roles in cellular and organismal functions. Transcript levels are in part determined by the combinatorial and overlapping functions of multiple transcription factors (TFs bound to gene promoters. Thus, TF-promoter interactions provide the basic molecular wiring of transcriptional regulatory networks. In plants, discovery of the functional roles of TFs is limited by an increased complexity of network circuitry due to a significant expansion of TF families. Here, we present the construction of a comprehensive collection of Arabidopsis TFs clones created to provide a versatile resource for uncovering TF biological functions. We leveraged this collection by implementing a high-throughput DNA binding assay and identified direct regulators of a key clock gene (CCA1 that provide molecular links between different signaling modules and the circadian clock. The resources introduced in this work will significantly contribute to a better understanding of the transcriptional regulatory landscape of plant genomes.

  20. Degradation of the Separase-cleaved Rec8, a Meiotic Cohesin Subunit, by the N-end Rule Pathway.

    Science.gov (United States)

    Liu, Yu-Jiao; Liu, Chao; Chang, ZeNan; Wadas, Brandon; Brower, Christopher S; Song, Zhen-Hua; Xu, Zhi-Liang; Shang, Yong-Liang; Liu, Wei-Xiao; Wang, Li-Na; Dong, Wen; Varshavsky, Alexander; Hu, Rong-Gui; Li, Wei

    2016-04-01

    The Ate1 arginyltransferase (R-transferase) is a component of the N-end rule pathway, which recognizes proteins containing N-terminal degradation signals called N-degrons, polyubiquitylates these proteins, and thereby causes their degradation by the proteasome. Ate1 arginylates N-terminal Asp, Glu, or (oxidized) Cys. The resulting N-terminal Arg is recognized by ubiquitin ligases of the N-end rule pathway. In the yeastSaccharomyces cerevisiae, the separase-mediated cleavage of the Scc1/Rad21/Mcd1 cohesin subunit generates a C-terminal fragment that bears N-terminal Arg and is destroyed by the N-end rule pathway without a requirement for arginylation. In contrast, the separase-mediated cleavage of Rec8, the mammalian meiotic cohesin subunit, yields a fragment bearing N-terminal Glu, a substrate of the Ate1 R-transferase. Here we constructed and used a germ cell-confinedAte1(-/-)mouse strain to analyze the separase-generated C-terminal fragment of Rec8. We show that this fragment is a short-lived N-end rule substrate, that its degradation requires N-terminal arginylation, and that maleAte1(-/-)mice are nearly infertile, due to massive apoptotic death ofAte1(-/-)spermatocytes during the metaphase of meiosis I. These effects ofAte1ablation are inferred to be caused, at least in part, by the failure to destroy the C-terminal fragment of Rec8 in the absence of N-terminal arginylation. PMID:26858254

  1. Arabidopsis AtADF1 is Functionally Affected by Mutations on Actin Binding Sites

    Institute of Scientific and Technical Information of China (English)

    Chun-Hai Dong; Wei-Ping Tang; Jia-Yao Liu

    2013-01-01

    The plant actin depolymerizing factor (ADF) binds to both monomeric and filamentous actin,and is directly involved in the depolymerization of actin filaments.To better understand the actin binding sites of the Arabidopsis thaliana L.AtADF1,we generated mutants of AtADF1 and investigated their functions in vitro and in vivo.Analysis of mutants harboring amino acid substitutions revealed that charged residues (Arg98 and Lys100) located at the α-helix 3 and forming an actin binding site together with the N-terminus are essential for both G-and F-actin binding.The basic residues on the β-strand 5 (K82/A) and the α-helix 4 (R135/A,R137/A) form another actin binding site that is important for F-actin binding.Using transient expression of CFP-tagged AtADF1 mutant proteins in onion (Allium cepa) peel epidermal cells and transgenic Arabidopsis thaliana L.plants overexpressing these mutants,we analyzed how these mutant proteins regulate actin organization and affect seedling growth.Our results show that the ADF mutants with a lower affinity for actin filament binding can still be functional,unless the affinity foractin monomers is also affected.The G-actin binding activity of the ADF plays an essential role in actin binding,depolymerization of actin polymers,and therefore in the control of actin organization.

  2. The Function of the Early Trichomes Gene in Arabidopsis and Maize.

    Energy Technology Data Exchange (ETDEWEB)

    Scott Poethig

    2011-12-05

    Lateral organ polarity in Arabidopsis is regulated by antagonistic interactions between genes that promote either adaxial or abaxial identity, but the molecular basis of this interaction is largely unknown. We show that the adaxial regulator ASYMMETRIC LEAVES2 (AS2) is a direct target of the abaxial regulator KANADI1 (KAN1), and that KAN1 represses the transcription of AS2 in abaxial cells. Mutation of a single nucleotide in a KAN1 binding site in the AS2 promoter causes AS2 to be ectopically expressed in abaxial cells, resulting in a dominant, adaxialized phenotype. We also show that the abaxial expression of KAN1 is mediated directly or indirectly by AS2. These results demonstrate that KAN1 acts as a transcriptional repressor and that mutually repressive interactions between KAN1 and AS2 contribute to the establishment of adaxial-abaxial polarity in plants. A screen for mutations that affect the expression of a GFP reporter for KANADI2 produced mutations in two genes, CENTER CITY (CCT) and GRAND CENTRAL (GCT). Mutations in GCT and CCT delay the specification of central and peripheral identity and the globular-to-heart transition, but have little or no effect on the initial growth rate of the embryo. Mutant embryos eventually recover and undergo relatively normal patterning, albeit at an inappropriate size. GCT and CCT were identified as the Arabidopsis orthologs of MED12 and MED13--evolutionarily conserved proteins that act in association with the Mediator complex to negatively regulate transcription. The predicted function of these proteins combined with the effect of gct and cct on embryo development suggests that MED12 and MED13 regulate pattern formation during Arabidopsis embryogenesis by transiently repressing a transcriptional program that interferes with this process. Their mutant phenotype reveals the existence of a previously unknown temporal regulatory mechanism in plant embryogenesis.

  3. Two Arabidopsis orthologs of the transcriptional coactivator ADA2 have distinct biological functions.

    Science.gov (United States)

    Hark, Amy T; Vlachonasios, Konstantinos E; Pavangadkar, Kanchan A; Rao, Sumana; Gordon, Hillary; Adamakis, Ioannis-Dimosthenis; Kaldis, Athanasios; Thomashow, Michael F; Triezenberg, Steven J

    2009-02-01

    Histone acetylation is an example of covalent modification of chromatin structure that has the potential to regulate gene expression. Gcn5 is a prototypical histone acetyltransferase that associates with the transcriptional coactivator Ada2. In Arabidopsis, two genes encode proteins that resemble yeast ADA2 and share approximately 45% amino acid sequence identity. We previously reported that plants harboring a T-DNA insertion in the ADA2b gene display a dwarf phenotype with developmental defects in several organs. Here we describe T-DNA insertion alleles in the ADA2a gene, which result in no dramatic growth or developmental phenotype. Both ADA2a and ADA2b are expressed in a variety of plant tissues; moreover, expression of ADA2a from a constitutive promoter fails to complement the ada2b-1 mutant phenotype, consistent with the hypothesis that the two proteins have distinct biochemical roles. To further probe the cellular roles of ADA2a and ADA2b, we studied the response of the transcriptional coactivator mutants to abiotic stress. Although ada2b seedlings display hypersensitivity to salt and abscisic acid and altered responses to low temperature stress, the responses of ada2a seedlings to abiotic stress generally parallel those of wildtype plants. Intriguingly, ada2a;ada2b double mutant plants display an intermediate, gcn5-like phenotype, suggesting that ADA2a and ADA2b each work independently with GCN5 to affect genome function in Arabidopsis.

  4. Regulation of WRKY46 transcription factor function by mitogen-activated protein kinases in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Arsheed Hussain Sheikh

    2016-02-01

    Full Text Available AbstractMitogen-activated protein kinase (MAPK cascades are central signalling pathways activated in plants after sensing internal developmental and external stress cues. Knowledge about the downstream substrate proteins of MAPKs is still limited in plants. We screened Arabidopsis WRKY transcription factors as potential targets downstream of MAPKs, and concentrated on characterizing WRKY46 as a substrate of the MAPK, MPK3. Mass spectrometry revealed in vitro phosphorylation of WRKY46 at amino acid position S168 by MPK3. However, mutagenesis studies showed that a second phosphosite, S250, can also be phosphorylated. Elicitation with pathogen-associated molecular patterns (PAMPs, such as the bacterial flagellin-derived flg22 peptide led to in vivo destabilization of WRKY46 in Arabidopsis protoplasts. Mutation of either phosphorylation site reduced the PAMP-induced degradation of WRKY46. Furthermore, the protein for the double phosphosite mutant is expressed at higher levels compared to wild-type proteins or single phosphosite mutants. In line with its nuclear localization and predicted function as a transcriptional activator, overexpression of WRKY46 in protoplasts raised basal plant defence as reflected by the increase in promoter activity of the PAMP-responsive gene, NHL10, in a MAPK-dependent manner. Thus, MAPK-mediated regulation of WRKY46 is a mechanism to control plant defence.

  5. Regulation of WRKY46 Transcription Factor Function by Mitogen-Activated Protein Kinases in Arabidopsis thaliana.

    Science.gov (United States)

    Sheikh, Arsheed H; Eschen-Lippold, Lennart; Pecher, Pascal; Hoehenwarter, Wolfgang; Sinha, Alok K; Scheel, Dierk; Lee, Justin

    2016-01-01

    Mitogen-activated protein kinase (MAPK) cascades are central signaling pathways activated in plants after sensing internal developmental and external stress cues. Knowledge about the downstream substrate proteins of MAPKs is still limited in plants. We screened Arabidopsis WRKY transcription factors as potential targets downstream of MAPKs, and concentrated on characterizing WRKY46 as a substrate of the MAPK, MPK3. Mass spectrometry revealed in vitro phosphorylation of WRKY46 at amino acid position S168 by MPK3. However, mutagenesis studies showed that a second phosphosite, S250, can also be phosphorylated. Elicitation with pathogen-associated molecular patterns (PAMPs), such as the bacterial flagellin-derived flg22 peptide led to in vivo destabilization of WRKY46 in Arabidopsis protoplasts. Mutation of either phosphorylation site reduced the PAMP-induced degradation of WRKY46. Furthermore, the protein for the double phosphosite mutant is expressed at higher levels compared to wild-type proteins or single phosphosite mutants. In line with its nuclear localization and predicted function as a transcriptional activator, overexpression of WRKY46 in protoplasts raised basal plant defense as reflected by the increase in promoter activity of the PAMP-responsive gene, NHL10, in a MAPK-dependent manner. Thus, MAPK-mediated regulation of WRKY46 is a mechanism to control plant defense. PMID:26870073

  6. MADS on the move : a study on MADS domain protein function and movement during floral development in Arabidopsis thaliana

    NARCIS (Netherlands)

    Urbanus, S.L.

    2010-01-01

    In this thesis we investigated the behaviour of fluorescently-tagged MADS domain proteins during floral development in the model plant Arabidopsis thaliana, and explored the importance of intercellular transport via plasmodesmata for MADS domain transcription factor functioning. The MADS domain tran

  7. Arabidopsis CPR5 is a senescence-regulatory gene with pleiotropic functions as predicted by the evolutionary theory of senescence

    NARCIS (Netherlands)

    Jing, Hai-Chun; Anderson, Lisa; Sturre, Marcel J. G.; Hille, Jacques; Dijkwel, Paul P.

    2007-01-01

    Arabidopsis CPR5 is a senescence-regulatory gene with pleiotropic functions as predicted by the evolutionary theory of senescence Hai-Chun Jing1,2, Lisa Anderson3, Marcel J.G. Sturre1, Jacques Hille1 and Paul P. Dijkwel1,* 1Molecular Biology of Plants, Groningen Biomolecular Sciences and Biotechnolo

  8. Calcium-Dependent Protein Kinase CPK21 Functions in Abiotic Stress Response in Arabidopsis thaliana

    Institute of Scientific and Technical Information of China (English)

    Sandra Franz; Britta Ehlert; Anja Liese; Joachim Kurth; Anne-Claire Cazalé; Tina Romeis

    2011-01-01

    Calcium-dependent protein kinases(CDPKs)comprise a family of plant serine/threonine protein kinases in which the calcium sensing domain and the kinase effector domain are combined within one molecule.So far,a biological function in abiotic stress signaling has only been reported for few CDPK isoforms,whereas the underlying biochemical mechanism for these CDPKs is still mainly unknown.Here,we show that CPK21 from Arabidopsis thaliana is biochemically activated in vivo in response to hyperosmotic stress.Loss-of-function seedlings of cpk21 are more tolerant to hyperosmotic stress and mutant plants show increased stress responses with respect to marker gene expression and metabolite accumulation.In transgenic Arabidopsis complementation lines in the cpk21 mutant background,in which either CPK21 wildtype,or a full-length enzyme variant carrying an amino-acid substitution were stably expressed,stress responsitivity was restored by CPK21 but not with the kinase inactive variant.The biochemical characterization of in planta synthesized and purified CPK21 protein revealed that within the calcium-binding domain,N-terminal EF1- and EF2-motifs compared to C-terminal EF3- and EF4-motifs differ in their contribution to calcium-regulated kinase activity,suggesting a crucial role for the N-terminal EF-hand pair.Our data provide evidence for CPK21 contributing in abiotic stress signaling and suggest that the N-terminal EF-hand pair is a calcium-sensing determinant controlling specificity of CPK21 function.

  9. An Arabidopsis aspartic protease functions as an anti-cell-death component in reproduction and embryogenesis.

    Science.gov (United States)

    Ge, Xiaochun; Dietrich, Charles; Matsuno, Michiyo; Li, Guojing; Berg, Howard; Xia, Yiji

    2005-03-01

    The components and pathways that regulate and execute developmental cell death programmes in plants remain largely unknown. We have found that the PROMOTION OF CELL SURVIVAL 1 (PCS1) gene in Arabidopsis, which encodes an aspartic protease, has an important role in determining the fate of cells in embryonic development and in reproduction processes. The loss-of-function mutation of PCS1 causes degeneration of both male and female gametophytes and excessive cell death of developing embryos. Conversely, ectopic expression of PCS1 causes the septum and stomium cells that normally die in the anther wall to survive instead, leading to a failure in anther dehiscence and male sterility. PCS1 provides a new avenue for understanding the mechanisms of the programmed cell death processes that are associated with developmental pathways in plants and makes available a useful tool for engineering the male sterility trait for hybrid seed production.

  10. Structural Determinants of Arabidopsis thaliana Hyponastic Leaves 1 Function In Vivo

    Science.gov (United States)

    Burdisso, Paula; Milia, Fernando; Schapire, Arnaldo L.; Bologna, Nicolás G.; Palatnik, Javier F.; Rasia, Rodolfo M.

    2014-01-01

    MicroRNAs have turned out to be important regulators of gene expression. These molecules originate from longer transcripts that are processed by ribonuclease III (RNAse III) enzymes. Dicer proteins are essential RNAse III enzymes that are involved in the generation of microRNAs (miRNAs) and other small RNAs. The correct function of Dicer relies on the participation of accessory dsRNA binding proteins, the exact function of which is not well-understood so far. In plants, the double stranded RNA binding protein Hyponastic Leaves 1 (HYL1) helps Dicer Like protein (DCL1) to achieve an efficient and precise excision of the miRNAs from their primary precursors. Here we dissected the regions of HYL1 that are essential for its function in Arabidopsis thaliana plant model. We generated mutant forms of the protein that retain their structure but affect its RNA-binding properties. The mutant versions of HYL1 were studied both in vitro and in vivo, and we were able to identify essential aminoacids/residues for its activity. Remarkably, mutation and even ablation of one of the purportedly main RNA binding determinants does not give rise to any major disturbances in the function of the protein. We studied the function of the mutant forms in vivo, establishing a direct correlation between affinity for the pri-miRNA precursors and protein activity. PMID:25409478

  11. Investigating the Molecular Mechanism of TSO1 Function in Arabidopsis cell division and meristem development

    Energy Technology Data Exchange (ETDEWEB)

    Zhongchi Liu

    2004-10-01

    Unlike animals, plants are constantly exposed to environmental mutagens including ultraviolet light and reactive oxygen species. Further, plant cells are totipotent with highly plastic developmental programs. An understanding of molecular mechanisms underlying the ability of plants to monitor and repair its DNA and to eliminate damaged cells are of great importance. Previously we have identified two genes, TSO1 and TSO2, from a flowering plant Arabidopsis thaliana. Mutations in these two genes cause callus-like flowers, fasciated shoot apical meristems, and abnormal cell division, indicating that TSO1 and TSO2 may encode important cell cycle regulators. Previous funding from DOE led to the molecular cloning of TSO1, which was shown to encode a novel nuclear protein with two CXC domains suspected to bind DNA. This DOE grant has allowed us to characterize and isolate TSO2 that encodes the small subunit of the ribonucleotide reductase (RNR). RNR comprises two large subunits (R1) an d two small subunits (R2), catalyzes a rate-limiting step in the production of deoxyribonucleotides needed for DNA replication and repair. Previous studies in yeast and mammals indicated that defective RNR often led to cell cycle arrest, growth retardation and p53-dependent apoptosis while abnormally elevated RNR activities led to higher mutation rates. Subsequently, we identified two additional R2 genes, R2A and R2B in the Arabidopsis genome. Using reverse genetics, mutations in R2A and R2B were isolated, and double and triple mutants among the three R2 genes (TSO2, R2A and R2B) were constructed and analyzed. We showed that Arabidopsis tso2 mutants, with reduced dNTP levels, were more sensitive to UV-C. While r2a or r2b single mutants did not exhibit any phenotypes, tso2 r2b double mutants were embryonic lethal and tso2 r2a double mutants were seedling lethal indicating redundant functions among the three R2 genes. Furthermore, tso2 r2a double mutants exhibited increased DNA dam age

  12. Structure and biochemical function of a prototypical Arabidopsis U-box domain

    DEFF Research Database (Denmark)

    Andersen, Pernille; Kragelund, Birthe B; Olsen, Addie N;

    2004-01-01

    U-box proteins, as well as other proteins involved in regulated protein degradation, are apparently over-represented in Arabidopsis compared with other model eukaryotes. The Arabidopsis protein AtPUB14 contains a typical U-box domain followed by an Armadillo repeat region, a domain organization...

  13. miRFANs: an integrated database for Arabidopsis thaliana microRNA function annotations

    Directory of Open Access Journals (Sweden)

    Liu Hui

    2012-05-01

    Full Text Available Abstract Background Plant microRNAs (miRNAs have been revealed to play important roles in developmental control, hormone secretion, cell differentiation and proliferation, and response to environmental stresses. However, our knowledge about the regulatory mechanisms and functions of miRNAs remains very limited. The main difficulties lie in two aspects. On one hand, the number of experimentally validated miRNA targets is very limited and the predicted targets often include many false positives, which constrains us to reveal the functions of miRNAs. On the other hand, the regulation of miRNAs is known to be spatio-temporally specific, which increases the difficulty for us to understand the regulatory mechanisms of miRNAs. Description In this paper we present miRFANs, an online database for Arabidopsis thalianamiRNA function annotations. We integrated various type of datasets, including miRNA-target interactions, transcription factor (TF and their targets, expression profiles, genomic annotations and pathways, into a comprehensive database, and developed various statistical and mining tools, together with a user-friendly web interface. For each miRNA target predicted by psRNATarget, TargetAlign and UEA target-finder, or recorded in TarBase and miRTarBase, the effect of its up-regulated or down-regulated miRNA on the expression level of the target gene is evaluated by carrying out differential expression analysis of both miRNA and targets expression profiles acquired under the same (or similar experimental condition and in the same tissue. Moreover, each miRNA target is associated with gene ontology and pathway terms, together with the target site information and regulating miRNAs predicted by different computational methods. These associated terms may provide valuable insight for the functions of each miRNA. Conclusion First, a comprehensive collection of miRNA targets for Arabidopsis thaliana provides valuable information about the functions of

  14. POPCORN functions in the auxin pathway to regulate embryonic body plan and meristem organization in Arabidopsis.

    Science.gov (United States)

    Xiang, Daoquan; Yang, Hui; Venglat, Prakash; Cao, Yongguo; Wen, Rui; Ren, Maozhi; Stone, Sandra; Wang, Edwin; Wang, Hong; Xiao, Wei; Weijers, Dolf; Berleth, Thomas; Laux, Thomas; Selvaraj, Gopalan; Datla, Raju

    2011-12-01

    The shoot and root apical meristems (SAM and RAM) formed during embryogenesis are crucial for postembryonic plant development. We report the identification of POPCORN (PCN), a gene required for embryo development and meristem organization in Arabidopsis thaliana. Map-based cloning revealed that PCN encodes a WD-40 protein expressed both during embryo development and postembryonically in the SAM and RAM. The two pcn alleles identified in this study are temperature sensitive, showing defective embryo development when grown at 22°C that is rescued when grown at 29°C. In pcn mutants, meristem-specific expression of WUSCHEL (WUS), CLAVATA3, and WUSCHEL-RELATED HOMEOBOX5 is not maintained; SHOOTMERISTEMLESS, BODENLOS (BDL) and MONOPTEROS (MP) are misexpressed. Several findings link PCN to auxin signaling and meristem function: ectopic expression of DR5(rev):green fluorescent protein (GFP), pBDL:BDL-GFP, and pMP:MP-β-glucuronidase in the meristem; altered polarity and expression of pPIN1:PIN1-GFP in the apical domain of the developing embryo; and resistance to auxin in the pcn mutants. The bdl mutation rescued embryo lethality of pcn, suggesting that improper auxin response is involved in pcn defects. Furthermore, WUS, PINFORMED1, PINOID, and TOPLESS are dosage sensitive in pcn, suggesting functional interaction. Together, our results suggest that PCN functions in the auxin pathway, integrating auxin signaling in the organization and maintenance of the SAM and RAM.

  15. Microtubules Are Essential for Guard-Cell Function in Vicia and Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    William Eisinger; David Ehrhardt; Winslow Briggs

    2012-01-01

    Radially arranged cortical microtubules are a prominent feature of guard cells.Guard cells expressing GFPtubulin showed consistent changes in the appearance of microtubules when stomata opened or closed.Guard cells showed fewer microtubule structures as stomata closed,whether induced by transfer to darkness,ABA,hydrogen peroxide,or sodium hydrogen carbonate.Guard cells kept in the dark (closed stomata) showed increases in microtubule structures and stomatal aperture on light treatment.GFP-EB1,marking microtubule growing plus ends,showed no change in number of plus ends or velocity of assembly on stomatal closure.Since the number of growing plus ends and the rate of plus-end growth did not change when microtubule structure numbers declined,microtubule instability and/or rearrangement must be responsible for the apparent loss of microtubules.Guard cells with closed stomata showed more cytosolic GFP-fluorescence than those with open stomata as cortical microtubules became disassembled,although with a large net loss in total fluorescence.Microtubule-targeted drugs blocked guard-cell function in Vicia and Arabidopsis.Oryzalin disrupted guard-cell microtubules and prevented stomatal opening and taxol stabilized guard-cell microtubules and delayed stomatal closure.Gas exchange measurements indicated that the transgenes for fluorescent-labeled proteins did not disrupt normal stomatal function.These dynamic changes in guard-cell microtubules combined with our inhibitor studies provide evidence for an active role of microtubules in guard-cell function.

  16. Newly Described Components and Regulatory Mechanisms of Circadian Clock Function in Arabidopsis thaliana

    Institute of Scientific and Technical Information of China (English)

    Manuel Adrián Troncoso-Ponce; Paloma Mas

    2012-01-01

    The circadian clock temporally coordinates plant growth and metabolism in close synchronization with the diurnal and seasonal environmental changes.Research over the last decade has identified a number of clock components and a variety of regulatory mechanisms responsible for the rhythmic oscillations in metabolic and physiological activities.At the core of the clock,transcriptional/translational feedback loops modulate the expression of a significant proportion of the genome.In this article,we briefly describe some of the very recent advances that have improved our understanding of clock organization and function in Arabidopsis thaliana.The new studies illustrate the role of clock protein complex formation on circadian gating of plant growth and identify alternative splicing as a new regulatory mechanism for clock function.Examination of key clock properties such as temperature compensation has also opened new avenues for functional research within the plant clockwork.The emerging connections between the circadian clock and metabolism,hormone signaling and response to biotic and abiotic stress also add new layers of complexity to the clock network and underscore the significance of the circadian clock regulating the daily life of plants.

  17. Harpinxoo and Its Functional Domains Activate Pathogen-inducible Plant Promoters in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    PENGJian-Ling; BAOZhi-Long; LIPing; CHENGuang-Yong; WANGJin-Sheng; DONGHan-Song

    2004-01-01

    Harpins are bacterial proteins that can enhance plant growth and defense against pathogens and insects. To elaborate whether harpins perform the diverse functions in coordination with the activation of specific promoters that contain particular elements, we cloned pathogen-inducible plant promoters PPP1, PPP2, and PPP3 from tobacco and investigated their responses to harpinxoo or its truncated fragments DEG, DIR, and DPR (domains for enhancing plant growth, insect resistance and pathogen resistance). PPP1 contains an internal repeat composed of two tandem 111bp fragments; 111bp in the repeat was deleted in PPP2. PPP3 contains a bacteria-inducible element; PPP1 and PPP2 additionally contain TAC-1 and Eli boxes inducible correspondingly by salicylic acid (SA) and elicitors. Function of cloned PPPs was confirmed based on their activation in transgenic Arabidopsis plants by Ralstonia solanacearum (Ralston) or SA. Harpinxoo, DEG, DIR, or DPR activated PPP1 and PPP2 but not PPP3, consistent with the presence of Eli boxes in promoters. PPP1 was ca. 3-fold more active than PPP2, suggesting that the internal repeat affects levels of the promoter activation.

  18. Functional divergence of MYB-related genes, WEREWOLF and AtMYB23 in Arabidopsis.

    Science.gov (United States)

    Tominaga-Wada, Rumi; Nukumizu, Yuka; Sato, Shusei; Kato, Tomohiko; Tabata, Satoshi; Wada, Takuji

    2012-01-01

    Epidermal cell differentiation in Arabidopsis is studied as a model system to understand the mechanisms that determine the developmental end state of plant cells. MYB-related transcription factors are involved in cell fate determination. To examine the molecular basis of this process, we analyzed the functional relationship of two R2R3-type MYB genes, AtMYB23 (MYB23) and WEREWOLF (WER). MYB23 is involved in leaf trichome formation. WER represses root-hair formation. Swapping domains between MYB23 and WER, we found that a low homology region of MYB23 might be involved in ectopic trichome initiation on hypocotyls. MYB23 and all MYB23-WER (MW) chimeric transgenes rescued the increased root-hair phenotype of the wer-1 mutant. Although WER did not rescue the gl1-1 no-trichome phenotype, MYB23 and all MW chimeric transgenes rescued gl1-1. These results suggest that MYB23 acquired a specific function for trichome differentiation during evolution.

  19. Functional analysis of the epidermal-specific MYB genes CAPRICE and WEREWOLF in Arabidopsis.

    Science.gov (United States)

    Tominaga, Rumi; Iwata, Mineko; Okada, Kiyotaka; Wada, Takuji

    2007-07-01

    Epidermis cell differentiation in Arabidopsis thaliana is a model system for understanding the developmental end state of plant cells. Two types of MYB transcription factors, R2R3-MYB and R3-MYB, are involved in cell fate determination. To examine the molecular basis of this process, we analyzed the functional relationship of the R2R3-type MYB gene WEREWOLF (WER) and the R3-type MYB gene CAPRICE (CPC). Chimeric constructs made from the R3 MYB regions of WER and CPC used in reciprocal complementation experiments showed that the CPC R3 region cannot functionally substitute for the WER R3 region in the differentiation of hairless cells. However, WER R3 can substantially substitute for CPC R3. There are no differences in yeast interaction assays of WER or WER chimera proteins with GLABRA3 (GL3) or ENHANCER OF GLABRA3 (EGL3). CPC and CPC chimera proteins also have similar activity in preventing GL3 WER and EGL3 WER interactions. Furthermore, we showed by gel mobility shift assays that WER chimera proteins do not bind to the GL2 promoter region. However, a CPC chimera protein, which harbors the WER R3 motif, still binds to the GL2 promoter region.

  20. Structural and functional analysis of VQ motif-containing proteins in Arabidopsis as interacting proteins of WRKY transcription factors.

    Science.gov (United States)

    Cheng, Yuan; Zhou, Yuan; Yang, Yan; Chi, Ying-Jun; Zhou, Jie; Chen, Jian-Ye; Wang, Fei; Fan, Baofang; Shi, Kai; Zhou, Yan-Hong; Yu, Jing-Quan; Chen, Zhixiang

    2012-06-01

    WRKY transcription factors are encoded by a large gene superfamily with a broad range of roles in plants. Recently, several groups have reported that proteins containing a short VQ (FxxxVQxLTG) motif interact with WRKY proteins. We have recently discovered that two VQ proteins from Arabidopsis (Arabidopsis thaliana), SIGMA FACTOR-INTERACTING PROTEIN1 and SIGMA FACTOR-INTERACTING PROTEIN2, act as coactivators of WRKY33 in plant defense by specifically recognizing the C-terminal WRKY domain and stimulating the DNA-binding activity of WRKY33. In this study, we have analyzed the entire family of 34 structurally divergent VQ proteins from Arabidopsis. Yeast (Saccharomyces cerevisiae) two-hybrid assays showed that Arabidopsis VQ proteins interacted specifically with the C-terminal WRKY domains of group I and the sole WRKY domains of group IIc WRKY proteins. Using site-directed mutagenesis, we identified structural features of these two closely related groups of WRKY domains that are critical for interaction with VQ proteins. Quantitative reverse transcription polymerase chain reaction revealed that expression of a majority of Arabidopsis VQ genes was responsive to pathogen infection and salicylic acid treatment. Functional analysis using both knockout mutants and overexpression lines revealed strong phenotypes in growth, development, and susceptibility to pathogen infection. Altered phenotypes were substantially enhanced through cooverexpression of genes encoding interacting VQ and WRKY proteins. These findings indicate that VQ proteins play an important role in plant growth, development, and response to environmental conditions, most likely by acting as cofactors of group I and IIc WRKY transcription factors.

  1. Assessing the functional coherence of modules found in multiple-evidence networks from Arabidopsis

    Directory of Open Access Journals (Sweden)

    Hodgman Charlie

    2011-05-01

    Full Text Available Abstract Background Combining multiple evidence-types from different information sources has the potential to reveal new relationships in biological systems. The integrated information can be represented as a relationship network, and clustering the network can suggest possible functional modules. The value of such modules for gaining insight into the underlying biological processes depends on their functional coherence. The challenges that we wish to address are to define and quantify the functional coherence of modules in relationship networks, so that they can be used to infer function of as yet unannotated proteins, to discover previously unknown roles of proteins in diseases as well as for better understanding of the regulation and interrelationship between different elements of complex biological systems. Results We have defined the functional coherence of modules with respect to the Gene Ontology (GO by considering two complementary aspects: (i the fragmentation of the GO functional categories into the different modules and (ii the most representative functions of the modules. We have proposed a set of metrics to evaluate these two aspects and demonstrated their utility in Arabidopsis thaliana. We selected 2355 proteins for which experimentally established protein-protein interaction (PPI data were available. From these we have constructed five relationship networks, four based on single types of data: PPI, co-expression, co-occurrence of protein names in scientific literature abstracts and sequence similarity and a fifth one combining these four evidence types. The ability of these networks to suggest biologically meaningful grouping of proteins was explored by applying Markov clustering and then by measuring the functional coherence of the clusters. Conclusions Relationship networks integrating multiple evidence-types are biologically informative and allow more proteins to be assigned to a putative functional module. Using additional

  2. Mutations in the Arabidopsis Peroxisomal ABC Transporter COMATOSE Allow Differentiation between Multiple Functions In Planta: Insights from an Allelic Series

    OpenAIRE

    Dietrich, Daniela; Schmuths, Heike; Lousa, Carine De Marcos; Baldwin, Jocelyn M.; Baldwin, Stephen A.; Baker, Alison; Theodoulou, Frederica L; Holdsworth, Michael J

    2009-01-01

    COMATOSE (CTS), the Arabidopsis homologue of human Adrenoleukodystrophy protein (ALDP), is required for import of substrates for peroxisomal β-oxidation. A new allelic series and a homology model based on the bacterial ABC transporter, Sav1866, provide novel insights into structure-function relations of ABC subfamily D proteins. In contrast to ALDP, where the majority of mutations result in protein absence from the peroxisomal membrane, all CTS mutants produced stable protein. Mutation of con...

  3. AtHSPR may function in salt-induced cell death and ER stress in Arabidopsis.

    Science.gov (United States)

    Yang, Tao; Zhang, Peng; Wang, Chongying

    2016-07-01

    Salt stress is a harmful and global abiotic stress to plants and has an adverse effect on all physiological processes of plants. Recently, we cloned and identified a novel AtHSPR (Arabidopsis thaliana Heat Shock Protein Related), which encodes a nuclear-localized protein with ATPase activity, participates in salt and drought tolerance in Arabidopsis. Transcript profiling analysis revealed a differential expression of genes involved in accumulation of reactive oxygen species (ROS), abscisic acid (ABA) signaling, stress response and photosynthesis between athspr mutant and WT under salt stress. Here, we provide further analysis of the data showing the regulation of salt-induced cell death and endoplasmic reticulum (ER) stress response in Arabidopsis and propose a hypothetical model for the role of AtHSPR in the regulation of the salt tolerance in Arabidopsis. PMID:27302034

  4. Inferring Hypotheses on Functional Relationships of Genes: Analysis of the Arabidopsis thaliana Subtilase Gene Family.

    Directory of Open Access Journals (Sweden)

    2005-09-01

    Full Text Available The gene family of subtilisin-like serine proteases (subtilases in Arabidopsis thaliana comprises 56 members, divided into six distinct subfamilies. Whereas the members of five subfamilies are similar to pyrolysins, two genes share stronger similarity to animal kexins. Mutant screens confirmed 144 T-DNA insertion lines with knockouts for 55 out of the 56 subtilases. Apart from SDD1, none of the confirmed homozygous mutants revealed any obvious visible phenotypic alteration during growth under standard conditions. Apart from this specific case, forward genetics gave us no hints about the function of the individual 54 non-characterized subtilase genes. Therefore, the main objective of our work was to overcome the shortcomings of the forward genetic approach and to infer alternative experimental approaches by using an integrative bioinformatics and biological approach. Computational analyses based on transcriptional co-expression and co-response pattern revealed at least two expression networks, suggesting that functional redundancy may exist among subtilases with limited similarity. Furthermore, two hubs were identified, which may be involved in signalling or may represent higher-order regulatory factors involved in responses to environmental cues. A particular enrichment of co-regulated genes with metabolic functions was observed for four subtilases possibly representing late responsive elements of environmental stress. The kexin homologs show stronger associations with genes of transcriptional regulation context. Based on the analyses presented here and in accordance with previously characterized subtilases, we propose three main functions of subtilases: involvement in (i control of development, (ii protein turnover, and (iii action as downstream components of signalling cascades. Supplemental material is available in the Plant Subtilase Database (PSDB (http://csbdb.mpimp-golm.mpg.de/psdb.html , as well as from the CSB.DB (http://csbdb.mpimp-golm.mpg.de.

  5. Inferring hypotheses on functional relationships of genes: Analysis of the Arabidopsis thaliana subtilase gene family.

    Directory of Open Access Journals (Sweden)

    Carsten Rautengarten

    2005-09-01

    Full Text Available The gene family of subtilisin-like serine proteases (subtilases in Arabidopsis thaliana comprises 56 members, divided into six distinct subfamilies. Whereas the members of five subfamilies are similar to pyrolysins, two genes share stronger similarity to animal kexins. Mutant screens confirmed 144 T-DNA insertion lines with knockouts for 55 out of the 56 subtilases. Apart from SDD1, none of the confirmed homozygous mutants revealed any obvious visible phenotypic alteration during growth under standard conditions. Apart from this specific case, forward genetics gave us no hints about the function of the individual 54 non-characterized subtilase genes. Therefore, the main objective of our work was to overcome the shortcomings of the forward genetic approach and to infer alternative experimental approaches by using an integrative bioinformatics and biological approach. Computational analyses based on transcriptional co-expression and co-response pattern revealed at least two expression networks, suggesting that functional redundancy may exist among subtilases with limited similarity. Furthermore, two hubs were identified, which may be involved in signalling or may represent higher-order regulatory factors involved in responses to environmental cues. A particular enrichment of co-regulated genes with metabolic functions was observed for four subtilases possibly representing late responsive elements of environmental stress. The kexin homologs show stronger associations with genes of transcriptional regulation context. Based on the analyses presented here and in accordance with previously characterized subtilases, we propose three main functions of subtilases: involvement in (i control of development, (ii protein turnover, and (iii action as downstream components of signalling cascades. Supplemental material is available in the Plant Subtilase Database (PSDB (http://csbdb.mpimp-golm.mpg.de/psdb.html, as well as from the CSB.DB (http://csbdb.mpimp-golm.mpg.de.

  6. Functional analysis of the Hikeshi-like protein and its interaction with HSP70 in Arabidopsis

    Energy Technology Data Exchange (ETDEWEB)

    Koizumi, Shinya; Ohama, Naohiko; Mizoi, Junya [Laboratory of Plant Molecular Physiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657 (Japan); Shinozaki, Kazuo [RIKEN Plant Science Center, 1-7-22 Suehiro-cho, Tsurumi, Yokohama, Kanagawa 230-0045 (Japan); Yamaguchi-Shinozaki, Kazuko, E-mail: akys@mail.ecc.u-tokyo.ac.jp [Laboratory of Plant Molecular Physiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657 (Japan)

    2014-07-18

    Highlights: • HKL, a Hikeshi homologous gene is identified in Arabidopsis. • HKL interacts with two HSP70 isoforms and regulates the subcellular localization of HSC70-1. • The two HSP70 translocate into nucleus in response to heat stress. • Overexpression of HKL confers thermotolerance in transgenic plants. - Abstract: Heat shock proteins (HSPs) refold damaged proteins and are an essential component of the heat shock response. Previously, the 70 kDa heat shock protein (HSP70) has been reported to translocate into the nucleus in a heat-dependent manner in many organisms. In humans, the heat-induced translocation of HSP70 requires the nuclear carrier protein Hikeshi. In the Arabidopsis genome, only one gene encodes a protein with high homology to Hikeshi, and we named this homolog Hikeshi-like (HKL) protein. In this study, we show that two Arabidopsis HSP70 isoforms accumulate in the nucleus in response to heat shock and that HKL interacts with these HSP70s. Our histochemical analysis revealed that HKL is predominantly expressed in meristematic tissues, suggesting the potential importance of HKL during cell division in Arabidopsis. In addition, we show that HKL regulates HSP70 localization, and HKL overexpression conferred thermotolerance to transgenic Arabidopsis plants. Our results suggest that HKL plays a positive role in the thermotolerance of Arabidopsis plants and cooperatively interacts with HSP70.

  7. Loss of actin cytoskeletal function and EDS1 activity, in combination, severely compromises non-host resistance in Arabidopsis against wheat powdery mildew.

    Science.gov (United States)

    Yun, Byung-Wook; Atkinson, Helen A; Gaborit, Charlotte; Greenland, Andy; Read, Nick D; Pallas, Jacqueline A; Loake, Gary J

    2003-06-01

    Plant immunity against the majority of the microbial pathogens is conveyed by a phenomenon known as non-host resistance (NHR). This defence mechanism affords durable protection to plant species against given species of phytopathogens. We investigated the genetic basis of NHR in Arabidopsis against the wheat powdery mildew fungus Blumeria graminis f. sp. tritici (Bgt). Both primary and appressorial germ tubes were produced from individual Bgt conidia on the surface of the Arabidopsis leaves. Attempted infection occasionally resulted in successful penetration, which led to the development of an abnormal unilateral haustorium. Inoculation of a series of Arabidopsis defence-related mutants with Bgt resulted in the attenuation of reactive oxygen intermediate (ROI) production and salicylic acid (SA)-dependent defence gene expression in eds1, pad4 and nahG plants, which are known to be defective in some aspects of host resistance. Furthermore, Bgt often developed bilateral haustoria in the mutant Arabidopsis lines that closely resembled those formed in wheat. A similar decrease in NHR was observed following treatment of the wild-type Arabidopsis plants with cytochalasin E, an inhibitor of actin microfilament polymerisation. In eds1 mutants, inhibition of actin polymerisation severely compromised NHR in Arabidopsis against Bgt. This permitted completion of the Bgt infection cycle on these plants. Therefore, actin cytoskeletal function and EDS1 activity, in combination, are major contributors to NHR in Arabidopsis against wheat powdery mildew.

  8. Structural and functional characteristics of cGMP-dependent methionine oxidation in Arabidopsis thaliana proteins

    KAUST Repository

    Marondedze, Claudius

    2013-01-05

    Background: Increasing structural and biochemical evidence suggests that post-translational methionine oxidation of proteins is not just a result of cellular damage but may provide the cell with information on the cellular oxidative status. In addition, oxidation of methionine residues in key regulatory proteins, such as calmodulin, does influence cellular homeostasis. Previous findings also indicate that oxidation of methionine residues in signaling molecules may have a role in stress responses since these specific structural modifications can in turn change biological activities of proteins. Findings. Here we use tandem mass spectrometry-based proteomics to show that treatment of Arabidopsis thaliana cells with a non-oxidative signaling molecule, the cell-permeant second messenger analogue, 8-bromo-3,5-cyclic guanosine monophosphate (8-Br-cGMP), results in a time-dependent increase in the content of oxidised methionine residues. Interestingly, the group of proteins affected by cGMP-dependent methionine oxidation is functionally enriched for stress response proteins. Furthermore, we also noted distinct signatures in the frequency of amino acids flanking oxidised and un-oxidised methionine residues on both the C- and N-terminus. Conclusions: Given both a structural and functional bias in methionine oxidation events in response to a signaling molecule, we propose that these are indicative of a specific role of such post-translational modifications in the direct or indirect regulation of cellular responses. The mechanisms that determine the specificity of the modifications remain to be elucidated. 2013 Marondedze et al.; licensee BioMed Central Ltd.

  9. Arabidopsis CALCINEURIN B-LIKE10 Functions Independently of the SOS Pathway during Reproductive Development in Saline Conditions.

    Science.gov (United States)

    Monihan, Shea M; Magness, Courtney A; Yadegari, Ramin; Smith, Steven E; Schumaker, Karen S

    2016-05-01

    The accumulation of sodium in soil (saline conditions) negatively affects plant growth and development. The Salt Overly Sensitive (SOS) pathway in Arabidopsis (Arabidopsis thaliana) functions to remove sodium from the cytosol during vegetative development preventing its accumulation to toxic levels. In this pathway, the SOS3 and CALCINEURIN B-LIKE10 (CBL10) calcium sensors interact with the SOS2 protein kinase to activate sodium/proton exchange at the plasma membrane (SOS1) or vacuolar membrane. To determine if the same pathway functions during reproductive development in response to salt, fertility was analyzed in wild type and the SOS pathway mutants grown in saline conditions. In response to salt, CBL10 functions early in reproductive development before fertilization, while SOS1 functions mostly after fertilization when seed development begins. Neither SOS2 nor SOS3 function in reproductive development in response to salt. Loss of CBL10 function resulted in reduced anther dehiscence, shortened stamen filaments, and aborted pollen development. In addition, cbl10 mutant pistils could not sustain the growth of wild-type pollen tubes. These results suggest that CBL10 is critical for reproductive development in the presence of salt and that it functions in different pathways during vegetative and reproductive development.

  10. Thioredoxin Reductase Type C (NTRC) Orchestrates Enhanced Thermotolerance to Arabidopsis by Its Redox-Dependent Holdase Chaperone Function

    Institute of Scientific and Technical Information of China (English)

    Ho Byoung Chae; Jeong Chan Moon; Mi Rim Shin; Yong Hun Chi; Young Jun Jung; Sun Yong Lee; Ganesh M.Nawkar

    2013-01-01

    Genevestigator analysis has indicated heat shock induction of transcripts for NADPH-thioredoxin reductase,type C (NTRC) in the light.Here we show overexpression of NTRC in Arabidopsis (NTRCoE) resulting in enhanced tolerance to heat shock,whereas NTRC knockout mutant plants (ntrcl) exhibit a temperature sensitive phenotype.To investigate the underlying mechanism of this phenotype,we analyzed the protein's biochemical properties and protein structure.NTRC assembles into homopolymeric structures of varying complexity with functions as a disulfide reductase,a foldase chaperone,and as a holdase chaperone.The multiple functions of NTRC are closely correlated with protein structure.Complexes of higher molecular weight (HMW) showed stronger activity as a holdase chaperone,while low molecular weight (LMW) species exhibited weaker holdase chaperone activity but stronger disulfide reductase and foldase chaperone activities.Heat shock converted LMW proteins into HMW complexes.Mutations of the two active site Cys residues of NTRC into Ser (C217/454S-NTRC) led to a complete inactivation of its disulfide reductase and foldase chaperone functions,but conferred only a slight decrease in its holdase chaperone function.The overexpression of the mutated C217/454S-NTRC provided Arabidopsis with a similar degree of thermotolerance compared with that of NTRCoE plants.However,after prolonged incubation under heat shock,NTRCoE plants tolerated the stress to a higher degree than C217/454S-NTRCoE plants.The results suggest that the heat shock-mediated holdase chaperone function of NTRC is responsible for the increased thermotolerance of Arabidopsis and the activity is significantly supported by NADPH.

  11. Developmental Functions of miR156-Regulated SQUAMOSA PROMOTER BINDING PROTEIN-LIKE (SPL) Genes in Arabidopsis thaliana.

    Science.gov (United States)

    Xu, Mingli; Hu, Tieqiang; Zhao, Jianfei; Park, Mee-Yeon; Earley, Keith W; Wu, Gang; Yang, Li; Poethig, R Scott

    2016-08-01

    Correct developmental timing is essential for plant fitness and reproductive success. Two important transitions in shoot development-the juvenile-to-adult vegetative transition and the vegetative-to-reproductive transition-are mediated by a group of genes targeted by miR156, SQUAMOSA PROMOTER BINDING PROTEIN (SBP) genes. To determine the developmental functions of these genes in Arabidopsis thaliana, we characterized their expression patterns, and their gain-of-function and loss-of-function phenotypes. Our results reveal that SBP-LIKE (SPL) genes in Arabidopsis can be divided into three functionally distinct groups: 1) SPL2, SPL9, SPL10, SPL11, SPL13 and SPL15 contribute to both the juvenile-to-adult vegetative transition and the vegetative-to-reproductive transition, with SPL9, SP13 and SPL15 being more important for these processes than SPL2, SPL10 and SPL11; 2) SPL3, SPL4 and SPL5 do not play a major role in vegetative phase change or floral induction, but promote the floral meristem identity transition; 3) SPL6 does not have a major function in shoot morphogenesis, but may be important for certain physiological processes. We also found that miR156-regulated SPL genes repress adventitious root development, providing an explanation for the observation that the capacity for adventitious root production declines as the shoot ages. miR156 is expressed at very high levels in young seedlings, and declines in abundance as the shoot develops. It completely blocks the expression of its SPL targets in the first two leaves of the rosette, and represses these genes to different degrees at later stages of development, primarily by promoting their translational repression. These results provide a framework for future studies of this multifunctional family of transcription factors, and offer new insights into the role of miR156 in Arabidopsis development. PMID:27541584

  12. Developmental Functions of miR156-Regulated SQUAMOSA PROMOTER BINDING PROTEIN-LIKE (SPL) Genes in Arabidopsis thaliana

    Science.gov (United States)

    Hu, Tieqiang; Park, Mee-Yeon; Earley, Keith W.; Wu, Gang; Yang, Li

    2016-01-01

    Correct developmental timing is essential for plant fitness and reproductive success. Two important transitions in shoot development—the juvenile-to-adult vegetative transition and the vegetative-to-reproductive transition—are mediated by a group of genes targeted by miR156, SQUAMOSA PROMOTER BINDING PROTEIN (SBP) genes. To determine the developmental functions of these genes in Arabidopsis thaliana, we characterized their expression patterns, and their gain-of-function and loss-of-function phenotypes. Our results reveal that SBP-LIKE (SPL) genes in Arabidopsis can be divided into three functionally distinct groups: 1) SPL2, SPL9, SPL10, SPL11, SPL13 and SPL15 contribute to both the juvenile-to-adult vegetative transition and the vegetative-to-reproductive transition, with SPL9, SP13 and SPL15 being more important for these processes than SPL2, SPL10 and SPL11; 2) SPL3, SPL4 and SPL5 do not play a major role in vegetative phase change or floral induction, but promote the floral meristem identity transition; 3) SPL6 does not have a major function in shoot morphogenesis, but may be important for certain physiological processes. We also found that miR156-regulated SPL genes repress adventitious root development, providing an explanation for the observation that the capacity for adventitious root production declines as the shoot ages. miR156 is expressed at very high levels in young seedlings, and declines in abundance as the shoot develops. It completely blocks the expression of its SPL targets in the first two leaves of the rosette, and represses these genes to different degrees at later stages of development, primarily by promoting their translational repression. These results provide a framework for future studies of this multifunctional family of transcription factors, and offer new insights into the role of miR156 in Arabidopsis development. PMID:27541584

  13. Molecular and functional characterization of a human ATM gene analogue at Arabidopsis thaliana

    International Nuclear Information System (INIS)

    The human ATM gene, whose inactivation is responsible for the human disease ataxia telangiectasia is conserved throughout the Eukaryotes and plays an important role in the cellular responses to DNA damage, in particular to DNA double-strand breaks (DSBs). Here we describe the identification of an Arabidopsis thaliana homologue of ATM (AtATM), and the molecular and cytological characterization of plants, hereafter called atm, carrying a disrupting T-DNA insertion in this gene. AtATM covers a 32 kb region on chromosome 3. The AtATM transcript has a complex structure, is 12 kb long and formed by 79 exons. The transcriptional level of AtATM is very low in all the tissues tested, and does not vary after exposure to ionizing radiations (IR). In atm plants, the protein is not detected suggesting the mutants are null. The atm mutants are partially sterile. Aberrant segregation of chromosomes during meiosis I on both male and female sides account for this sterility. However, meiotic recombination frequency is normal. Mutant plants are also hypersensitive to gamma rays and methyl methane sulfonate, but not to UV-B, pointing to a specific defect of atm mutants in the response to DNA DSBs. In plants, ionizing radiations induce a strong, rapid and transient transcriptional activation of genes involved in the cellular response to or the repair of DSBs. This transcriptional regulation of AtRAD51, AtPARP1, atGR1 and AtL1G4 is lost in the atm mutants . The absence of AtRAD51 induction associated with ionizing radiation sensitivity suggest that AtAtm play an important function in DSB repair by homologous recombination. In addition we show that homologous intra-chromosomal recombination frequency is elevated in the mutant comparing to wild-type, with or without gamma irradiation. These results show the implication of AtAtm in the genomic stability. (author)

  14. Stress-related function of bHLH109 in somatic embryo induction in Arabidopsis.

    Science.gov (United States)

    Nowak, Katarzyna; Gaj, Małgorzata D

    2016-04-01

    The bHLH109 gene of the bHLH family was identified among the transcription factor encoding genes that were differentially expressed in an embryogenic culture of Arabidopsis. A strong activation of bHLH109 expression was found to be associated with somatic embryogenesis (SE) induction. Several pieces of evidence suggested the involvement of bHLH109 in SE, including the high stimulation of the gene expression in SE-induced explants, which contrasts to the drastically lower level of the gene transcripts in the non-embryogenic callus and in tissue that is induced towards shoot regeneration via organogenesis. Moreover, in contrast to the overexpression of bHLH109, which has been indicated to enhance SE induction in a culture, the bhlh109 knock-out mutation was found to impair the embryogenic potential of explants. In order to identify the genes interacting with the bHLH109, the candidate co-expressed genes were identified in a yeast one hybrid assay. The in vitro regulatory interactions that were identified were verified through mutant and expression analysis. The results suggest that in SE bHLH109 acts as an activator of ECP63, a member of the LEA (LATE EMBRYOGENESIS ABUNDANT) family. Among the potential regulators of bHLH109, three candidates (At5g61620, bZIP4 and bZIP43) were indicated to possibly control bHLH109. The functions of all of the genes that are assumed to interact with bHLH109 are annotated to stress responses. Collectively, the results of the study provide new evidence that cell responses to stress that is imposed under in vitro conditions underlies the promotion of SE. bHLH109 may play a central role in the stress-related mechanism of SE induction via an increased accumulation of the LEA protein (ECP63), which results in the enhanced tolerance of the cells to stress. PMID:26973252

  15. Programmed cell death activated by Rose Bengal in Arabidopsis thaliana cell suspension cultures requires functional chloroplasts.

    Science.gov (United States)

    Gutiérrez, Jorge; González-Pérez, Sergio; García-García, Francisco; Daly, Cara T; Lorenzo, Oscar; Revuelta, José L; McCabe, Paul F; Arellano, Juan B

    2014-07-01

    Light-grown Arabidopsis thaliana cell suspension culture (ACSC) were subjected to mild photooxidative damage with Rose Bengal (RB) with the aim of gaining a better understanding of singlet oxygen-mediated defence responses in plants. Additionally, ACSC were treated with H2O2 at concentrations that induced comparable levels of protein oxidation damage. Under low to medium light conditions, both RB and H2O2 treatments activated transcriptional defence responses and inhibited photosynthetic activity, but they differed in that programmed cell death (PCD) was only observed in cells treated with RB. When dark-grown ACSC were subjected to RB in the light, PCD was suppressed, indicating that the singlet oxygen-mediated signalling pathway in ACSC requires functional chloroplasts. Analysis of up-regulated transcripts in light-grown ACSC, treated with RB in the light, showed that both singlet oxygen-responsive transcripts and transcripts with a key role in hormone-activated PCD (i.e. ethylene and jasmonic acid) were present. A co-regulation analysis proved that ACSC treated with RB exhibited higher correlation with the conditional fluorescence (flu) mutant than with other singlet oxygen-producing mutants or wild-type plants subjected to high light. However, there was no evidence for the up-regulation of EDS1, suggesting that activation of PCD was not associated with the EXECUTER- and EDS1-dependent signalling pathway described in the flu mutant. Indigo Carmine and Methylene Violet, two photosensitizers unable to enter chloroplasts, did not activate transcriptional defence responses in ACSC; however, whether this was due to their location or to their inherently low singlet oxygen quantum efficiencies was not determined.

  16. POPCORN Functions in the Auxin Pathway to Regulate Embryonic Body Plan and Meristem Organization in Arabidopsis

    NARCIS (Netherlands)

    Xiang, D.Q.; Yang, H.; Venglat, P.; Cao, Y.G.; Wen, R.; Ren, M.Z.; Stone, S.; Wang, E.; Wang, H.; Xiao, W.; Weijers, D.; Berleth, T.; Laux, T.; Selvaraj, G.; Datla, R.

    2011-01-01

    The shoot and root apical meristems (SAM and RAM) formed during embryogenesis are crucial for postembryonic plant development. We report the identification of POPCORN (PCN), a gene required for embryo development and meristem organization in Arabidopsis thaliana. Map-based cloning revealed that PCN

  17. Rapid assessment of gene function in the circadian clock using artificial microRNA in Arabidopsis mesophyll protoplasts.

    Science.gov (United States)

    Kim, Jeongsik; Somers, David E

    2010-10-01

    Rapid assessment of the effect of reduced levels of gene products is often a bottleneck in determining how to proceed with an interesting gene candidate. Additionally, gene families with closely related members can confound determination of the role of even a single one of the group. We describe here an in vivo method to rapidly determine gene function using transient expression of artificial microRNAs (amiRNAs) in Arabidopsis (Arabidopsis thaliana) mesophyll protoplasts. We use a luciferase-based reporter of circadian clock activity to optimize and validate this system. Protoplasts transiently cotransfected with promoter-luciferase and gene-specific amiRNA plasmids sustain free-running rhythms of bioluminescence for more than 6 d. Using both amiRNA plasmids available through the Arabidopsis Biological Resource Center, as well as custom design of constructs using the Weigel amiRNA design algorithm, we show that transient knockdown of known clock genes recapitulates the same circadian phenotypes reported in the literature for loss-of-function mutant plants. We additionally show that amiRNA designed to knock down expression of the casein kinase II β-subunit gene family lengthens period, consistent with previous reports of a short period in casein kinase II β-subunit overexpressors. Our results demonstrate that this system can facilitate a much more rapid analysis of gene function by obviating the need to initially establish stably transformed transgenics to assess the phenotype of gene knockdowns. This approach will be useful in a wide range of plant disciplines when an endogenous cell-based phenotype is observable or can be devised, as done here using a luciferase reporter.

  18. The Arabidopsis thaliana proteome harbors undiscovered multi-domain molecules with functional guanylyl cyclase catalytic centers

    KAUST Repository

    Wong, Aloysius Tze

    2013-07-08

    Background: Second messengers link external cues to complex physiological responses. One such messenger, 3\\',5\\'-cyclic guanosine monophosphate (cGMP), has been shown to play a key role in many physiological responses in plants. However, in higher plants, guanylyl cyclases (GCs), enzymes that generate cGMP from guanosine-5\\'-triphosphate (GTP) have remained elusive until recently. GC search motifs constructed from the alignment of known GCs catalytic centers form vertebrates and lower eukaryotes have led to the identification of a number of plant GCs that have been characterized in vitro and in vivo.Presentation of the hypothesis.Recently characterized GCs in Arabidopsis thaliana contributed to the development of search parameters that can identify novel candidate GCs in plants. We hypothesize that there are still a substantial number (> 40) of multi-domain molecules with potentially functional GC catalytic centers in plants that remain to be discovered and characterized. Testing the hypothesis. The hypothesis can be tested, firstly, by computational methods constructing 3D models of selected GC candidates using available crystal structures as templates. Homology modeling must include substrate docking that can provide support for the structural feasibility of the GC catalytic centers in those candidates. Secondly, recombinant peptides containing the GC domain need to be tested in in vitro GC assays such as the enzyme-linked immune-sorbent assay (ELISA) and/or in mass spectrometry based cGMP assays. In addition, quantification of in vivo cGMP transients with fluorescent cGMP-reporter assays in wild-type or selected mutants will help to elucidate the biological role of novel GCs.Implications of the hypothesis.If it turns out that plants do harbor a large number of functional GC domains as part of multi-domain enzymes, then major new insights will be gained into the complex signal transduction pathways that link cGMP to fundamental processes such as ion transport

  19. Root exudation of phytochemicals in Arabidopsis follows specific patterns that are developmentally programmed and correlate with soil microbial functions.

    Directory of Open Access Journals (Sweden)

    Jacqueline M Chaparro

    Full Text Available Plant roots constantly secrete compounds into the soil to interact with neighboring organisms presumably to gain certain functional advantages at different stages of development. Accordingly, it has been hypothesized that the phytochemical composition present in the root exudates changes over the course of the lifespan of a plant. Here, root exudates of in vitro grown Arabidopsis plants were collected at different developmental stages and analyzed using GC-MS. Principle component analysis revealed that the composition of root exudates varied at each developmental stage. Cumulative secretion levels of sugars and sugar alcohols were higher in early time points and decreased through development. In contrast, the cumulative secretion levels of amino acids and phenolics increased over time. The expression in roots of genes involved in biosynthesis and transportation of compounds represented in the root exudates were consistent with patterns of root exudation. Correlation analyses were performed of the in vitro root exudation patterns with the functional capacity of the rhizosphere microbiome to metabolize these compounds at different developmental stages of Arabidopsis grown in natural soils. Pyrosequencing of rhizosphere mRNA revealed strong correlations (p<0.05 between microbial functional genes involved in the metabolism of carbohydrates, amino acids and secondary metabolites with the corresponding compounds released by the roots at particular stages of plant development. In summary, our results suggest that the root exudation process of phytochemicals follows a developmental pattern that is genetically programmed.

  20. Functional characterization of aroA from Rhizobium leguminosarum with significant glyphosate tolerance in transgenic Arabidopsis.

    Science.gov (United States)

    Han, Jing; Tian, Yong-Sheng; Xu, Jing; Wang, Li-Juan; Wang, Bo; Peng, Ri-He; Yao, Quan-Hong

    2014-09-01

    Glyphosate is the active component of the top-selling herbicide, the phytotoxicity of which is due to its inhibition of the shikimic acid pathway. 5-Enolpyruvylshikimate-3-phosphate synthase (EPSPS) is a key enzyme in the shikimic acid pathway. Glyphosate tolerance in plants can be achieved by the expression of a glyphosate-insensitive aroA gene (EPSPS). In this study, we used a PCR-based two-step DNA synthesis method to synthesize a new aroA gene (aroAR. leguminosarum) from Rhizobium leguminosarum. In vitro glyphosate sensitivity assays showed that aroAR. leguminosarum is glyphosate tolerant. The new gene was then expressed in E. coli and key kinetic values of the purified enzyme were determined. Furthermore, we transformed the aroA gene into Arabidopsis thaliana by the floral dip method. Transgenic Arabidopsis with the aroAR. leguminosarum gene was obtained to prove its potential use in developing glyphosate-resistant crops.

  1. Structure and function of centromeric and pericentromeric heterochromatin in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Lauriane eSimon

    2015-11-01

    Full Text Available The centromere is a specific chromosomal region where the kinetochore assembles to ensure the faithful segregation of sister chromatids during mitosis and meiosis. Centromeres are defined by a local enrichment of the specific histone variant CenH3 mostly at repetitive satellite sequences. A larger pericentromeric region containing repetitive sequences and transposable elements surrounds the centromere that adopts a particular chromatin state characterized by specific histone variants and post-translational modifications and forms a transcriptionally repressive chromosomal environment. In the model organism Arabidopsis thaliana centromeric and pericentromeric domains form conspicuous heterochromatin clusters called chromocenters in interphase. Here we discuss, using Arabidopsis as example, recent insight into mechanisms involved in maintenance and establishment of centromeric and pericentromeric chromatin signatures as well as in chromocenter formation.

  2. Functional analysis of the theobroma cacao NPR1 gene in arabidopsis

    OpenAIRE

    Verica Joseph; Liu Yi; Maximova Siela N; Shi Zi; Guiltinan Mark J

    2010-01-01

    Abstract Background The Arabidopsis thaliana NPR1 gene encodes a transcription coactivator (NPR1) that plays a major role in the mechanisms regulating plant defense response. After pathogen infection and in response to salicylic acid (SA) accumulation, NPR1 translocates from the cytoplasm into the nucleus where it interacts with other transcription factors resulting in increased expression of over 2000 plant defense genes contributing to a pathogen resistance response. Results A putative Theo...

  3. Isolation and Functional Analysis of ZmLTP3, a Homologue to Arabidopsis LTP3

    Directory of Open Access Journals (Sweden)

    Guo-Hui Ma

    2013-03-01

    Full Text Available Plant lipid transfer proteins (LTPs are encoded by multigene families and play important roles in plant physiology. One full-length cDNA encoding an Arabidopsis LTP3 homologue was isolated from maize by RT-PCR and named as ZmLTP3. RT-PCR analysis indicated that the ZmLTP3 expression is induced by salicylic acid (SA, mannitol and salt. Furthermore, in different tissues the ZmLTP3 displayed different expression patterns, indicating that ZmLTP3 may play multiple roles in stress resistance. Over-expression of ZmLTP3 in wild-type Arabidopsis resulted in the increased salt tolerance. Under salt stress condition, compared to wild-type (WT plants, transgenic Arabidopsis grew better, had higher seedling fresh (FW, dry weight (DW, seed yields, proline content and lower MDA content and relative electric conductivity level. Our results suggest that maize ZmLTP3 might encode a member of LTPs family and play roles in salt resistance.

  4. Isolation and Functional Analysis of ZmLTP3, a Homologue to Arabidopsis LTP3.

    Science.gov (United States)

    Zou, Hua-Wen; Tian, Xiao-Hai; Ma, Guo-Hui; Li, Zhi-Xin

    2013-01-01

    Plant lipid transfer proteins (LTPs) are encoded by multigene families and play important roles in plant physiology. One full-length cDNA encoding an Arabidopsis LTP3 homologue was isolated from maize by RT-PCR and named as ZmLTP3. RT-PCR analysis indicated that the ZmLTP3 expression is induced by salicylic acid (SA), mannitol and salt. Furthermore, in different tissues the ZmLTP3 displayed different expression patterns, indicating that ZmLTP3 may play multiple roles in stress resistance. Over-expression of ZmLTP3 in wild-type Arabidopsis resulted in the increased salt tolerance. Under salt stress condition, compared to wild-type (WT) plants, transgenic Arabidopsis grew better, had higher seedling fresh (FW), dry weight (DW), seed yields, proline content and lower MDA content and relative electric conductivity level. Our results suggest that maize ZmLTP3 might encode a member of LTPs family and play roles in salt resistance. PMID:23455470

  5. Arabidopsis CPR5 is a senescence-regulatory gene with pleiotropic functions as predicted by the evolutionary theory of senescence.

    Science.gov (United States)

    Jing, Hai-Chun; Anderson, Lisa; Sturre, Marcel J G; Hille, Jacques; Dijkwel, Paul P

    2007-01-01

    Evolutionary theories of senescence predict that genes with pleiotropic functions are important for senescence regulation. In plants there is no direct molecular genetic test for the existence of such senescence-regulatory genes. Arabidopsis cpr5 mutants exhibit multiple phenotypes including hypersensitivity to various signalling molecules, constitutive expression of pathogen-related genes, abnormal trichome development, spontaneous lesion formation, and accelerated leaf senescence. These indicate that CPR5 is a beneficial gene which controls multiple facets of the Arabidopsis life cycle. Ectopic expression of CPR5 restored all the mutant phenotypes. However, in transgenic plants with increased CPR5 transcripts, accelerated leaf senescence was observed in detached leaves and at late development around 50 d after germination, as illustrated by the earlier onset of senescence-associated physiological and molecular markers. Thus, CPR5 has early-life beneficial effects by repressing cell death and insuring normal plant development, but late-life deleterious effects by promoting developmental senescence. As such, CPR5 appears to function as a typical senescence-regulatory gene as predicted by the evolutionary theories of senescence.

  6. Efficient and high-throughput vector construction and Agrobacterium-mediated transformation of Arabidopsis thaliana suspension-cultured cells for functional genomics.

    Science.gov (United States)

    Ogawa, Yoichi; Dansako, Tomoko; Yano, Kentaro; Sakurai, Nozomu; Suzuki, Hideyuki; Aoki, Koh; Noji, Masaaki; Saito, Kazuki; Shibata, Daisuke

    2008-02-01

    We established a large-scale, high-throughput protocol to construct Arabidopsis thaliana suspension-cultured cell lines, each of which carries a single transgene, using Agrobacterium-mediated transformation. We took advantage of RIKEN Arabidopsis full-length (RAFL) cDNA clones and the Gateway cloning system for high-throughput preparation of binary vectors carrying individual full-length cDNA sequences. Throughout all cloning steps, multiple-well plates were used to treat 96 samples simultaneously in a high-throughput manner. The optimal conditions for Agrobacterium-mediated transformation of 96 independent binary vector constructs were established to obtain transgenic cell lines efficiently. We evaluated the protocol by generating transgenic Arabidopsis T87 cell lines carrying individual 96 metabolism-related RAFL cDNA fragments, and showed that the protocol was useful for high-throughput and large-scale production of gain-of-function lines for functional genomics.

  7. Expression profiling and functional analysis reveals that TOR is a key player in regulating photosynthesis and phytohormone signaling pathways in Arabidopsis.

    Science.gov (United States)

    Dong, Pan; Xiong, Fangjie; Que, Yumei; Wang, Kai; Yu, Lihua; Li, Zhengguo; Ren, Maozhi

    2015-01-01

    Target of rapamycin (TOR) acts as a master regulator to control cell growth by integrating nutrient, energy, and growth factors in all eukaryotic species. TOR plays an evolutionarily conserved role in regulating the transcription of genes associated with anabolic and catabolic processes in Arabidopsis, but little is known about the functions of TOR in photosynthesis and phytohormone signaling, which are unique features of plants. In this study, AZD8055 (AZD) was screened as the strongest active-site TOR inhibitor (asTORi) in Arabidopsis compared with TORIN1 and KU63794 (KU). Gene expression profiles were evaluated using RNA-seq after treating Arabidopsis seedlings with AZD. More than three-fold differentially expressed genes (DEGs) were identified in AZD-treated plants relative to rapamycin-treated plants in previous studies. Most of the DEGs and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways involved in cell wall elongation, ribosome biogenesis, and cell autophagy were common to both AZD- and rapamycin-treated samples, but AZD displayed much broader and more efficient inhibition of TOR compared with rapamycin. Importantly, the suppression of TOR by AZD resulted in remodeling of the expression profile of the genes associated with photosynthesis and various phytohormones, indicating that TOR plays a crucial role in modulating photosynthesis and phytohormone signaling in Arabidopsis. These newly identified DEGs expand the understanding of TOR signaling in plants. This study elucidates the novel functions of TOR in photosynthesis and phytohormone signaling and provides a platform to study the downstream targets of TOR in Arabidopsis.

  8. Conserved CDC20 cell cycle functions are carried out by two of the five isoforms in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Zoltán Kevei

    Full Text Available BACKGROUND: The CDC20 and Cdh1/CCS52 proteins are substrate determinants and activators of the Anaphase Promoting Complex/Cyclosome (APC/C E3 ubiquitin ligase and as such they control the mitotic cell cycle by targeting the degradation of various cell cycle regulators. In yeasts and animals the main CDC20 function is the destruction of securin and mitotic cyclins. Plants have multiple CDC20 gene copies whose functions have not been explored yet. In Arabidopsis thaliana there are five CDC20 isoforms and here we aimed at defining their contribution to cell cycle regulation, substrate selectivity and plant development. METHODOLOGY/PRINCIPAL FINDINGS: Studying the gene structure and phylogeny of plant CDC20s, the expression of the five AtCDC20 gene copies and their interactions with the APC/C subunit APC10, the CCS52 proteins, components of the mitotic checkpoint complex (MCC and mitotic cyclin substrates, conserved CDC20 functions could be assigned for AtCDC20.1 and AtCDC20.2. The other three intron-less genes were silent and specific for Arabidopsis. We show that AtCDC20.1 and AtCDC20.2 are components of the MCC and interact with mitotic cyclins with unexpected specificity. AtCDC20.1 and AtCDC20.2 are expressed in meristems, organ primordia and AtCDC20.1 also in pollen grains and developing seeds. Knocking down both genes simultaneously by RNAi resulted in severe delay in plant development and male sterility. In these lines, the meristem size was reduced while the cell size and ploidy levels were unaffected indicating that the lower cell number and likely slowdown of the cell cycle are the cause of reduced plant growth. CONCLUSIONS/SIGNIFICANCE: The intron-containing CDC20 gene copies provide conserved and redundant functions for cell cycle progression in plants and are required for meristem maintenance, plant growth and male gametophyte formation. The Arabidopsis-specific intron-less genes are possibly "retrogenes" and have hitherto undefined

  9. AGO6 functions in RNA-mediated transcriptional gene silencing in shoot and root meristems in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Changho Eun

    Full Text Available RNA-directed DNA methylation (RdDM is a small interfering RNA (siRNA-mediated epigenetic modification that contributes to transposon silencing in plants. RdDM requires a complex transcriptional machinery that includes specialized RNA polymerases, named Pol IV and Pol V, as well as chromatin remodelling proteins, transcription factors, RNA binding proteins, and other plant-specific proteins whose functions are not yet clarified. In Arabidopsis thaliana, DICER-LIKE3 and members of the ARGONAUTE4 group of ARGONAUTE (AGO proteins are involved, respectively, in generating and using 24-nt siRNAs that trigger methylation and transcriptional gene silencing of homologous promoter sequences. AGO4 is the main AGO protein implicated in the RdDM pathway. Here we report the identification of the related AGO6 in a forward genetic screen for mutants defective in RdDM and transcriptional gene silencing in shoot and root apical meristems in Arabidopsis thaliana. The identification of AGO6, and not AGO4, in our screen is consistent with the primary expression of AGO6 in shoot and root growing points.

  10. Functional characterization of Arabidopsis NaCl-inducible WRKY25 and WRKY33 transcription factors in abiotic stresses.

    Science.gov (United States)

    Jiang, Yuanqing; Deyholos, Michael K

    2009-01-01

    Previous microarray analyses of Arabidopsis roots identified two closely related WRKY transcription factors (WRKY25 and WRKY33) among the transcripts that increased in abundance following treatment with NaCl. Here, we report further characterization of these genes, which we found to be inducible by a variety of abiotic stresses in an SOS-pathway independent manner, although WRKY33 induction was dependent on ABA signaling. Transcripts of both genes were detected in roots and leaves, while specific patterns of enrichment were observed in stems and floral buds for WRKY25 and WRKY33, respectively. We also identified upstream intergenic regions from each gene that were sufficient to confer stress-inducible expression on a reporter gene. However, the stress sensitivity of wrky25 null mutants did not differ from wild-type under any assay condition, while wrky33 null mutants and wrky25wrky33 double mutants showed only a moderate increase in NaCl-sensitivity, suggesting functional redundancy with other transcription factors. Nevertheless, overexpression of WRKY25 or WRKY33 was sufficient to increase Arabidopsis NaCl tolerance, while increasing sensitivity to ABA. Through microarray analyses of relevant genotypes, we identified 31 and 208 potential downstream targets of WRKY25 and WRKY33, respectively, most of which contained a W-box in their upstream regions.

  11. Functional properties of a cysteine proteinase from pineapple fruit with improved resistance to fungal pathogens in Arabidopsis thaliana.

    Science.gov (United States)

    Wang, Wei; Zhang, Lu; Guo, Ning; Zhang, Xiumei; Zhang, Chen; Sun, Guangming; Xie, Jianghui

    2014-01-01

    In plant cells, many cysteine proteinases (CPs) are synthesized as precursors in the endoplasmic reticulum, and then are subject to post-translational modifications to form the active mature proteinases. They participate in various cellular and physiological functions. Here, AcCP2, a CP from pineapple fruit (Ananas comosus L.) belonging to the C1A subfamily is analyzed based on the molecular modeling and homology alignment. Transcripts of AcCP2 can be detected in the different parts of fruits (particularly outer sarcocarps), and gradually increased during fruit development until maturity. To analyze the substrate specificity of AcCP2, the recombinant protein was overexpressed and purified from Pichia pastoris. The precursor of purified AcCP2 can be processed to a 25 kDa active form after acid treatment (pH 4.3). Its optimum proteolytic activity to Bz-Phe-Val-Arg-NH-Mec is at neutral pH. In addition, the overexpression of AcCP2 gene in Arabidopsis thaliana can improve the resistance to fungal pathogen of Botrytis cinerea. These data indicate that AcCP2 is a multifunctional proteinase, and its expression could cause fruit developmental characteristics of pineapple and resistance responses in transgenic Arabidopsis plants.

  12. Functional Properties of a Cysteine Proteinase from Pineapple Fruit with Improved Resistance to Fungal Pathogens in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Wei Wang

    2014-02-01

    Full Text Available In plant cells, many cysteine proteinases (CPs are synthesized as precursors in the endoplasmic reticulum, and then are subject to post-translational modifications to form the active mature proteinases. They participate in various cellular and physiological functions. Here, AcCP2, a CP from pineapple fruit (Ananas comosus L. belonging to the C1A subfamily is analyzed based on the molecular modeling and homology alignment. Transcripts of AcCP2 can be detected in the different parts of fruits (particularly outer sarcocarps, and gradually increased during fruit development until maturity. To analyze the substrate specificity of AcCP2, the recombinant protein was overexpressed and purified from Pichia pastoris. The precursor of purified AcCP2 can be processed to a 25 kDa active form after acid treatment (pH 4.3. Its optimum proteolytic activity to Bz-Phe-Val-Arg-NH-Mec is at neutral pH. In addition, the overexpression of AcCP2 gene in Arabidopsis thaliana can improve the resistance to fungal pathogen of Botrytis cinerea. These data indicate that AcCP2 is a multifunctional proteinase, and its expression could cause fruit developmental characteristics of pineapple and resistance responses in transgenic Arabidopsis plants.

  13. Partial functional conservation of IRX10 homologs in physcomitrella patens and Arabidopsis thaliana indicates an evolutionary step contributing to vascular formation in land plants

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    Hörnblad Emma

    2013-01-01

    Full Text Available Abstract Background Plant cell walls are complex multicomponent structures that have evolved to fulfil an essential function in providing strength and protection to cells. Hemicelluloses constitute a key component of the cell wall and recently a number of the genes thought to encode the enzymes required for its synthesis have been identified in Arabidopsis. The acquisition of hemicellulose synthesis capability is hypothesised to have been an important step in the evolution of higher plants. Results Analysis of the Physcomitrella patens genome has revealed the presence of homologs for all of the Arabidopsis glycosyltransferases including IRX9, IRX10 and IRX14 required for the synthesis of the glucuronoxylan backbone. The Physcomitrella IRX10 homolog is expressed in a variety of moss tissues which were newly formed or undergoing expansion. There is a high degree of sequence conservation between the Physcomitrella IRX10 and Arabidopsis IRX10 and IRX10-L. Despite this sequence similarity, the Physcomitrella IRX10 gene is only able to partially rescue the Arabidopsis irx10 irx10-L double mutant indicating that there has been a neo- or sub-functionalisation during the evolution of higher plants. Analysis of the monosaccharide composition of stems from the partially rescued Arabidopsis plants does not show any significant change in xylose content compared to the irx10 irx10-L double mutant. Likewise, knockout mutants of the Physcomitrella IRX10 gene do not result in any visible phenotype and there is no significant change in monosaccharide composition of the cell walls. Conclusions The fact that the Physcomitrella IRX10 (PpGT47A protein can partially complement an Arabidopsis irx10 irx10-L double mutant suggests that it shares some function with the Arabidopsis proteins, but the lack of a phenotype in knockout lines shows that the function is not required for growth or development under normal conditions in Physcomitrella. In contrast, the Arabidopsis

  14. Non-redundant functions of two proline dehydrogenase isoforms in Arabidopsis

    OpenAIRE

    Müller Gudrun; Eckard Sonja; Funck Dietmar

    2010-01-01

    Abstract Background Proline (Pro) accumulation is a widespread response of prokaryotic and eukaryotic cells subjected to osmotic stress or dehydration. When the cells are released from stress, Pro is degraded to glutamate by Pro-dehydrogenase (ProDH) and Pyrroline-5-carboxylate dehydrogenase (P5CDH), which are both mitochondrial enzymes in eukaryotes. While P5CDH is a single copy gene in Arabidopsis, two ProDH genes have been identified in the genome. Until now, only ProDH1 (At3g30775) had be...

  15. Isolation and Functional Analysis of ZmLTP3, a Homologue to Arabidopsis LTP3

    OpenAIRE

    Guo-Hui Ma; Xiao-Hai Tian; Hua-Wen Zou; Zhi-Xin Li

    2013-01-01

    Plant lipid transfer proteins (LTPs) are encoded by multigene families and play important roles in plant physiology. One full-length cDNA encoding an Arabidopsis LTP3 homologue was isolated from maize by RT-PCR and named as ZmLTP3. RT-PCR analysis indicated that the ZmLTP3 expression is induced by salicylic acid (SA), mannitol and salt. Furthermore, in different tissues the ZmLTP3 displayed different expression patterns, indicating that ZmLTP3 may play multiple roles in stress resistance. Ove...

  16. Biochemical and functional analysis of CTR1, a protein kinase that negatively regulates ethylene signaling in Arabidopsis

    Science.gov (United States)

    Huang, Yafan; Li, Hui; Hutchison, Claire E.; Laskey, James; Kieber, Joseph J.

    2003-01-01

    CTR1 encodes a negative regulator of the ethylene response pathway in Arabidopsis thaliana. The C-terminal domain of CTR1 is similar to the Raf family of protein kinases, but its first two-thirds encodes a novel protein domain. We used a variety of approaches to investigate the function of these two CTR1 domains. Recombinant CTR1 protein was purified from a baculoviral expression system, and shown to possess intrinsic Ser/Thr protein kinase activity with enzymatic properties similar to Raf-1. Deletion of the N-terminal domain did not elevate the kinase activity of CTR1, indicating that, at least in vitro, this domain does not autoinhibit kinase function. Molecular analysis of loss-of-function ctr1 alleles indicated that several mutations disrupt the kinase catalytic domain, and in vitro studies confirmed that at least one of these eliminates kinase activity, which indicates that kinase activity is required for CTR1 function. One missense mutation, ctr1-8, was found to result from an amino acid substitution within a new conserved motif within the N-terminal domain. Ctr1-8 has no detectable effect on the kinase activity of CTR1 in vitro, but rather disrupts the interaction with the ethylene receptor ETR1. This mutation also disrupts the dominant negative effect that results from overexpression of the CTR1 amino-terminal domain in transgenic Arabidopsis. These results suggest that CTR1 interacts with ETR1 in vivo, and that this association is required to turn off the ethylene-signaling pathway.

  17. The Elucidation of the Interactome of 16 Arabidopsis bZIP Factors Reveals Three Independent Functional Networks

    Science.gov (United States)

    Llorca, Carles Marco; Berendzen, Kenneth Wayne; Malik, Waqas Ahmed; Mahn, Stefan; Piepho, Hans-Peter; Zentgraf, Ulrike

    2015-01-01

    The function of the bZIP transcription factors is strictly dependent on their ability to dimerize. Heterodimerization has proven to be highly specific and is postulated to operate as a combinatorial mechanism allowing the generation of a large variety of dimers with unique qualities by specifically combining a small set of monomers; an assumption that has not yet been tested systematically. Here, the interaction pattern and the transactivation properties of 16 Arabidopsis thaliana bZIPs are examined in transiently transformed Arabidopsis protoplasts to deliver a perspective on the relationship between bZIP dimerization and function. An interaction matrix of bZIPs belonging to the C, G, H, and S1 bZIP groups was resolved by Bimolecular Fluorescent Complementation (BiFC) coupled to quantitative flow cytometric analysis, while an extensive GUS reporter gene assay was carried out to determine the effect of different bZIP pairs on the expression of four different known bZIP-targeted promoters. Statistical data treatment and complementary bioinformatic analysis were performed to substantiate the biological findings. According to these results, the 16 bZIPs interact in three isolated networks, within which their members dimerize non-specifically and exhibit a significant level of functional redundancy. A coherent explanation for these results is supported by in silico analysis of differences in the length, structure and composition of their leucine zippers and appears to explain their dimerization specificity and dynamics observed in vivo quite well. A model in which the bZIP networks act as functional units is proposed. PMID:26452049

  18. Comprehensive Functional Analysis of the Catalase Gene Family in Arabidopsis thaliana

    Institute of Scientific and Technical Information of China (English)

    Yan-Yan Du; Peng-Cheng Wang; Jia Chen; Chun-Peng Song

    2008-01-01

    In Arabidopsis, catalase (CAT) genes encode a small family of proteins including CAT1, CAT2 and CAT3, which catalyze the decomposition of hydrogen peroxide (H2O2) and play an important role in controlling homeostasis of reactive oxygen species (ROS). Here, we analyze the expression profiles and activities of three catalases under different treatments including drought, cold, oxidative stresses, abscisic acid and salicylic acid in Arabidopsis. Our results reveal that CAT1 is an important player in the removal of H2O2 generated under various environmental stresses. CAT2 and CAT3 are major H2O2 scavengers that contribute to ROS homeostasis in light or darkness, respectively. In addition, CAT2 is activated by cold and drought stresses and CAT3 is mainly enhanced by abscisic acid and oxidative treatments as well as at the senescence stage. These results, together with previous data, suggest that the network of transcriptional control explains how CATs and other scavenger enzymes such as peroxidase and superoxide dismutase may be coordinately regulated during development, but differentially expressed in response to different stresses for controlling ROS homeostasis.

  19. Structural and Functional Studies of the Mitochondrial Cysteine Desulfurase from Arabidopsis thaliana

    Institute of Scientific and Technical Information of China (English)

    Valeria R; Turowski; Maria V.Busi; Diego F.Gomez-Casati

    2012-01-01

    AtNfs1 is the Arabidopsis thaliana mitochondrial homolog of the bacterial cysteine desulfurases NifS and lscS,having an essential role in cellular Fe-S cluster assembly.Homology modeling of AtNfs1m predicts a high global similarity with E.coli IscS showing a full conservation of residues involved in the catalytic site,whereas the chloroplastic AtNfs2 is more similar to the Synechocystis sp.SufS.Pull-down assays showed that the recombinant mature form,AtNfs1m,specifically binds to Arabidopsis frataxin (AtFH).A hysteretic behavior,with a lag phase of several minutes,was observed and hysteretic parameters were affected by pre-incubation with AtFH.Moreover,AtFH modulates AtNfs1m kinetics,increasing Vmax and decreasing the S0.5 value for cysteine.Results suggest that AtFH plays an important role in the early steps of Fe-S cluster formation by regulating AtNfs1 activity in olant mitochondria.

  20. MICROTUBULE ORGANIZATION 1 Regulates Structure and Function of Microtubule Arrays during Mitosis and Cytokinesis in the Arabidopsis Root1[W

    Science.gov (United States)

    Kawamura, Eiko; Himmelspach, Regina; Rashbrooke, Madeleine C.; Whittington, Angela T.; Gale, Kevin R.; Collings, David A.; Wasteneys, Geoffrey O.

    2006-01-01

    MICROTUBULE ORGANIZATION 1 (MOR1) is a plant member of the highly conserved MAP215/Dis1 family of microtubule-associated proteins. Prior studies with the temperature-sensitive mor1 mutants of Arabidopsis (Arabidopsis thaliana), which harbor single amino acid substitutions in an N-terminal HEAT repeat, proved that MOR1 regulates cortical microtubule organization and function. Here we demonstrate by use of live cell imaging and immunolabeling that the mor1-1 mutation generates specific defects in the microtubule arrays of dividing vegetative cells. Unlike the universal cortical microtubule disorganization in elongating mor1-1 cells, disruption of mitotic and cytokinetic microtubule arrays was not detected in all dividing cells. Nevertheless, quantitative analysis identified distinct defects in preprophase bands (PPBs), spindles, and phragmoplasts. In nearly one-half of dividing cells at the restrictive temperature of 30°C, PPBs were not detected prior to spindle formation, and those that did form were often disrupted. mor1-1 spindles and phragmoplasts were short and abnormally organized and persisted for longer times than in wild-type cells. The reduced length of these arrays predicts that the component microtubule lengths are also reduced, suggesting that microtubule length is a critical determinant of spindle and phragmoplast structure, orientation, and function. Microtubule organizational defects led to aberrant chromosomal arrangements, misaligned or incomplete cell plates, and multinucleate cells. Antiserum raised against an N-terminal MOR1 sequence labeled the full length of microtubules in interphase arrays, PPBs, spindles, and phragmoplasts. Continued immunolabeling of the disorganized and short microtubules of mor1-1 at the restrictive temperature demonstrated that the mutant mor1-1L174F protein loses function without dissociating from microtubules, providing important insight into the mechanism by which MOR1 may regulate microtubule length. PMID:16377747

  1. The Structure of Sucrose Synthase-1 from Arabidopsis thaliana and Its Functional Implications

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Yi; Anderson, Spencer; Zhang, Yanfeng; Garavito, R. Michael (MSU); (NWU)

    2014-10-02

    Sucrose transport is the central system for the allocation of carbon resources in vascular plants. During growth and development, plants control carbon distribution by coordinating sites of sucrose synthesis and cleavage in different plant organs and different cellular locations. Sucrose synthase, which reversibly catalyzes sucrose synthesis and cleavage, provides a direct and reversible means to regulate sucrose flux. Depending on the metabolic environment, sucrose synthase alters its cellular location to participate in cellulose, callose, and starch biosynthesis through its interactions with membranes, organelles, and cytoskeletal actin. The x-ray crystal structure of sucrose synthase isoform 1 from Arabidopsis thaliana (AtSus1) has been determined as a complex with UDP-glucose and as a complex with UDP and fructose, at 2.8- and 2.85-{angstrom} resolutions, respectively. The AtSus1 structure provides insights into sucrose catalysis and cleavage, as well as the regulation of sucrose synthase and its interactions with cellular targets.

  2. A root chicory MADS box sequence and the Arabidopsis flowering repressor FLC share common features that suggest conserved function in vernalization and de-vernalization responses.

    Science.gov (United States)

    Périlleux, Claire; Pieltain, Alexandra; Jacquemin, Guillaume; Bouché, Frédéric; Detry, Nathalie; D'Aloia, Maria; Thiry, Laura; Aljochim, Pierre; Delansnay, Martin; Mathieu, Anne-Sophie; Lutts, Stanley; Tocquin, Pierre

    2013-08-01

    Root chicory (Cichorium intybus var. sativum) is a biennial crop, but is harvested to obtain root inulin at the end of the first growing season before flowering. However, cold temperatures may vernalize seeds or plantlets, leading to incidental early flowering, and hence understanding the molecular basis of vernalization is important. A MADS box sequence was isolated by RT-PCR and named FLC-LIKE1 (CiFL1) because of its phylogenetic positioning within the same clade as the floral repressor Arabidopsis FLOWERING LOCUS C (AtFLC). Moreover, over-expression of CiFL1 in Arabidopsis caused late flowering and prevented up-regulation of the AtFLC target FLOWERING LOCUS T by photoperiod, suggesting functional conservation between root chicory and Arabidopsis. Like AtFLC in Arabidopsis, CiFL1 was repressed during vernalization of seeds or plantlets of chicory, but repression of CiFL1 was unstable when the post-vernalization temperature was favorable to flowering and when it de-vernalized the plants. This instability of CiFL1 repression may be linked to the bienniality of root chicory compared with the annual lifecycle of Arabidopsis. However, re-activation of AtFLC was also observed in Arabidopsis when a high temperature treatment was used straight after seed vernalization, eliminating the promotive effect of cold on flowering. Cold-induced down-regulation of a MADS box floral repressor and its re-activation by high temperature thus appear to be conserved features of the vernalization and de-vernalization responses in distant species. PMID:23581257

  3. Functional analysis of the rice rubisco activase promoter in transgenic Arabidopsis

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Zhipan; Lu, Qingtao; Wen, Xiaogang [Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093 (China); Chen, Fan [Key Laboratory of Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100080 (China); Lu, Congming, E-mail: lucm@ibcas.ac.cn [Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093 (China)

    2012-02-17

    Highlights: Black-Right-Pointing-Pointer Rice rubisco activase promoter was analyzed in transgenic Arabidopsis system. Black-Right-Pointing-Pointer Region conferring tissue specific and light inducible expression of Rca was identified. Black-Right-Pointing-Pointer -58 to +43 bp region mediates tissue-specific expression of rice Rca. Black-Right-Pointing-Pointer Light inducible expression of rice Rca is mediated by -297 to -58 bp region. Black-Right-Pointing-Pointer Rice nuclear proteins bind specifically with the light inducible region. -- Abstract: To gain a better understanding of the regulatory mechanism of the rice rubisco activase (Rca) gene, variants of the Rca gene promoter (one full-length and four deletion mutants) fused to the coding region of the bacterial reporter gene {beta}-glucuronidase (GUS) were introduced into Arabidopsis via Agrobacterium-mediated transformation. Our results show that a 340 bp fragment spanning from -297 to +43 bp relative to the transcription initiation site is enough to promote tissue-specific and light-inducible expression of the rice Rca gene as done by the full-length promoter (-1428 to +43 bp). Further deletion analysis indicated that the region conferring tissue-specificity of Rca expression is localized within a 105 bp fragment from -58 to +43 bp, while light-inducible expression of Rca is mediated by the region from -297 to -58 bp. Gel shift assays and competition experiments demonstrated that rice nuclear proteins bind specifically with the fragment conferring light responsiveness at more than one binding site. This implies that multiple cis-elements may be involved in light-induced expression of the rice Rca gene. These works provide a useful reference for understanding transcriptional regulation mechanism of the rice Rca gene, and lay a strong foundation for further detection of related cis-elements and trans-factors.

  4. YUCCA6 over-expression demonstrates auxin function in delaying leaf senescence in Arabidopsis thaliana

    KAUST Repository

    Kim, Jeong Im

    2011-04-21

    The Arabidopsis thaliana YUCCA family of flavin monooxygenase proteins catalyses a rate-limiting step in de novo auxin biosynthesis. A YUCCA6 activation mutant, yuc6-1D, has been shown to contain an elevated free IAA level and to display typical high-auxin phenotypes. It is reported here that Arabidopsis plants over-expressing YUCCA6, such as the yuc6-1D activation mutant and 35S:YUC6 transgenic plants, displayed dramatic longevity. In addition, plants over-expressing YUCCA6 exhibited classical, delayed dark-induced and hormone-induced senescence in assays using detached rosette leaves. However, plants over-expressing an allele of YUCCA6, that carries mutations in the NADPH cofactor binding site, exhibited neither delayed leaf senescence phenotypes nor phenotypes typical of auxin overproduction. When the level of free IAA was reduced in yuc6-1D by conjugation to lysine, yuc6-1D leaves senesced at a rate similar to the wild-type leaves. Dark-induced senescence in detached leaves was accompanied by a decrease in their free IAA content, by the reduced expression of auxin biosynthesis enzymes such as YUCCA1 and YUCCA6 that increase cellular free IAA levels, and by the increased expression of auxin-conjugating enzymes encoded by the GH3 genes that reduce the cellular free auxin levels. Reduced transcript abundances of SAG12, NAC1, and NAC6 during senescence in yuc6-1D compared with the wild type suggested that auxin delays senescence by directly or indirectly regulating the expression of senescence-associated genes. 2011 The Author(s).

  5. Gene Network Analysis and Functional Studies of Senescence-associated Genes Reveal Novel Regulators of Arabidopsis Leaf Senescence

    Institute of Scientific and Technical Information of China (English)

    Zhonghai Li; Jinying Peng; Xing Wen; Hongwei Guo

    2012-01-01

    Plant leaf senescence has been recognized as the last phase of plant development,a highly ordered process regulated by genes known as senescence associated genes (SAGs).However,the function of most of SAGs in regulating leaf senescence as well as regulators of those functionally known SAGs are still unclear.We have previously developed a curated database of genes potentially associated with leaf senescence,the Leaf Senescence Database (LSD).In this study,we built gene networks to identify common regulators of leaf senescence in Arabidopsis thaliana using promoting or delaying senescence genes in LSD.Our results demonstrated that plant hormones cytokinin,auxin,nitric oxide as well as small molecules,such as Ca2+,delay leaf senescence.By contrast,ethylene,ABA,SA and JA as well as small molecules,such as oxygen,promote leaf senescence,altogether supporting the idea that phytohormones play a critical role in regulating leaf senescence.Functional analysis of candidate SAGs in LSD revealed that a WRKY transcription factor WRKY75 and a Cys2/His2-type transcription factor AZF2 are positive regulators of leaf senescence and loss-of-function of WRKY75 or AZF2 delayed leaf senescence.We also found that silencing of a protein phosphatase,AtMKP2,promoted early senescence.Collectively,LSD can serve as a comprehensive resource for systematic study of the molecular mechanism of leaf senescence as well as offer candidate genes for functional analyses.

  6. Arabidopsis cysteine-rich receptor-like kinase 45 functions in the responses to abscisic acid and abiotic stresses

    KAUST Repository

    Zhang, Xiujuan

    2013-06-01

    The phytohormone abscisic acid (ABA) regulates seed germination, plant growth and development, and response to abiotic stresses such as drought and salt stresses. Receptor-like kinases are well known signaling components that mediate plant responses to developmental and environmental stimuli. Here, we characterized the biological function of an ABA and stress-inducible cysteine-rich receptor-like protein kinase, CRK45, in ABA signaling in Arabidopsis thaliana. The crk45 mutant was less sensitive to ABA than the wild type during seed germination and early seedling development, whereas CRK45 overexpression plants were more sensitive to ABA compared to the wild type. Furthermore, overexpression of CRK45 led to hypersensitivity to salt and glucose inhibition of seed germination, whereas the crk45 mutant showed the opposite phenotypes. In addition, CRK45 overexpression plants had enhanced tolerance to drought. Gene expression analyses revealed that the expression of representative stress-responsive genes was significantly enhanced in CRK45 overexpression plants in response to salt stress. ABA biosynthetic genes such as NCED3,. 22NCED3, 9-Cis-Epoxycarotenoid Dioxygenase 3.NCED5,. 33NCED5, 9-Cis-Epoxycarotenoid Dioxygenase 5.ABA2,. 44ABA2, Abscisic Acid Deficient 2. and AAO355AAO3, Abscisic Aldehyde Oxidase 3. were also constitutively elevated in the CRK45 overexpression plants. We concluded that CRK45 plays an important role in ABA signaling that regulates Arabidopsis seeds germination, early seedling development and abiotic stresses response, by positively regulating ABA responses in these processes. © 2013 Elsevier Masson SAS.

  7. Thymidine kinases share a conserved function for nucleotide salvage and play an essential role in Arabidopsis thaliana growth and development.

    Science.gov (United States)

    Xu, Jing; Zhang, Lin; Yang, Dong-Lei; Li, Qun; He, Zuhua

    2015-12-01

    Thymidine kinases (TKs) are important components in the nucleotide salvage pathway. However, knowledge about plant TKs is quite limited. In this study, the molecular function of TKs in Arabidopsis thaliana was investigated. Two TKs were identified and named AtTK1 and AtTK2. Expression of both genes was ubiquitous, but AtTK1 was strongly expressed in high-proliferation tissues. AtTK1 was localized to the cytosol, whereas AtTK2 was localized to the mitochondria. Mutant analysis indicated that the two genes function coordinately to sustain normal plant development. Enzymatic assays showed that the two TK proteins shared similar catalytic specificity for pyrimidine nucleosides. They were able to complement an Escherichia coli strain lacking TK activity. 5'-Fluorodeoxyuridine (FdU) resistance and 5-ethynyl 2'-deoxyuridine (EdU) incorporation assays confirmed their activity in vivo. Furthermore, the tk mutant phenotype could be alleviated by nucleotide feeding, establishing that the biosynthesis of pyrimidine nucleotides was disrupted by the TK deficiency. Finally, both human and rice (Oryza sativa) TKs were able to rescue the tk mutants, demonstrating the functional conservation of TKs across organisms. Taken together, our findings clarify the specialized function of two TKs in A. thaliana and establish that the salvage pathway mediated by the kinases is essential for plant growth and development.

  8. Aluminum-activated citrate and malate transporters from the MATE and ALMT families function independently to confer Arabidopsis aluminum tolerance

    Science.gov (United States)

    Aluminum (Al) activated root malate and citrate exudation play an important role in Al tolerance in many plant species. AtALMT1, an Al-activated malate transporter, is a major contributor to Arabidopsis Al tolerance. Here, we demonstrate that a second, unrelated gene, AtMATE, encodes an Arabidopsi...

  9. Structure-function analysis of STRUBBELIG, an Arabidopsis atypical receptor-like kinase involved in tissue morphogenesis.

    Directory of Open Access Journals (Sweden)

    Prasad Vaddepalli

    Full Text Available Tissue morphogenesis in plants requires the coordination of cellular behavior across clonally distinct histogenic layers. The underlying signaling mechanisms are presently being unraveled and are known to include the cell surface leucine-rich repeat receptor-like kinase STRUBBELIG in Arabidopsis. To understand better its mode of action an extensive structure-function analysis of STRUBBELIG was performed. The phenotypes of 20 EMS and T-DNA-induced strubbelig alleles were assessed and homology modeling was applied to rationalize their possible effects on STRUBBELIG protein structure. The analysis was complemented by phenotypic, cell biological, and pharmacological investigations of a strubbelig null allele carrying genomic rescue constructs encoding fusions between various mutated STRUBBELIG proteins and GFP. The results indicate that STRUBBELIG accepts quite some sequence variation, reveal the biological importance for the STRUBBELIG N-capping domain, and reinforce the notion that kinase activity is not essential for its function in vivo. Furthermore, individual protein domains of STRUBBELIG cannot be related to specific STRUBBELIG-dependent biological processes suggesting that process specificity is mediated by factors acting together with or downstream of STRUBBELIG. In addition, the evidence indicates that biogenesis of a functional STRUBBELIG receptor is subject to endoplasmic reticulum-mediated quality control, and that an MG132-sensitive process regulates its stability. Finally, STRUBBELIG and the receptor-like kinase gene ERECTA interact synergistically in the control of internode length. The data provide genetic and molecular insight into how STRUBBELIG regulates intercellular communication in tissue morphogenesis.

  10. Amino acid substitution converts WEREWOLF function from an activator to a repressor of Arabidopsis non-hair cell development.

    Science.gov (United States)

    Tominaga-Wada, Rumi; Nukumizu, Yuka; Wada, Takuji

    2012-02-01

    Root hair cell or non-hair cell fate determination in Arabidopsis thaliana root epidermis is model system for plant cell development. Two types of MYB transcription factors, the R2R3-type MYB, WEREWOLF (WER), and an R3-type MYB, CAPRICE (CPC), are involved in this cell fate determination process. To study the molecular basis of this process, we analyzed the functional relationship of WER and CPC. WER-CPC chimeric constructs were made from WER where all or parts of the MYB R3 region were replaced with the corresponding regions from CPC R3, and the constructs were introduced into the cpc-2 mutant. Although, the WER gene did not rescue the cpc-2 mutant 'small number of root hairs' phenotype, the WER-CPC chimera with two amino acids substitution (WC6) completely rescued the cpc-2 mutant phenotype. Furthermore, the WER-CPC chimera with 37 amino acids substitution (WC5) excessively rescued the cpc-2 mutant and induced 2.5 times more root hairs than wild-type. Consistent with this phenotype, GL2 gene expression was strongly reduced in WC5 in a cpc-2 background. Our results suggest that swapping at least two amino acids is sufficient to convert WER to CPC function. Therefore, these key residues may have strongly contributed to the selection of these important functions over evolution.

  11. The WD40 repeat protein NEDD1 functions in microtubule organization during cell division in Arabidopsis thaliana.

    Science.gov (United States)

    Zeng, C J Tracy; Lee, Y-R Julie; Liu, Bo

    2009-04-01

    Although cells of flowering plants lack a structurally defined microtubule-organizing center like the centrosome, organization of the spindles and phragmoplasts in mitosis is known to involve the evolutionarily conserved gamma-tubulin complex. We have investigated the function of Arabidopsis thaliana NEDD1, a WD40 repeat protein related to the animal NEDD1/GCP-WD protein, which interacts with the gamma-tubulin complex. The NEDD1 protein decorates spindle microtubules (MTs) preferentially toward spindle poles and phragmoplast MTs toward their minus ends. A T-DNA insertional allele of the single NEDD1 gene was isolated and maintained in heterozygous sporophytes, and NEDD1's function in cell division was analyzed in haploid microspores produced by the heterozygote. In approximately half of the dividing microspores exhibiting aberrant MT organization, spindles were no longer restricted to the cell periphery and became abnormally elongated. After mitosis, MTs aggregated between reforming nuclei but failed to appear in a bipolar configuration. Consequently, defective microspores did not form a continuous cell plate, and two identical nuclei were produced with no differentiation into generative and vegetative cells. Our results support the notion that the plant NEDD1 homolog plays a critical role in MT organization during mitosis, and its function is likely linked to that of the gamma-tubulin complex. PMID:19383896

  12. Expansion and Functional Divergence of AP2 Group Genes in Spermatophytes Determined by Molecular Evolution and Arabidopsis Mutant Analysis

    Science.gov (United States)

    Wang, Pengkai; Cheng, Tielong; Lu, Mengzhu; Liu, Guangxin; Li, Meiping; Shi, Jisen; Lu, Ye; Laux, Thomas; Chen, Jinhui

    2016-01-01

    The APETALA2 (AP2) genes represent the AP2 group within a large group of DNA-binding proteins called AP2/EREBP. The AP2 gene is functional and necessary for flower development, stem cell maintenance, and seed development, whereas the other members of AP2 group redundantly affect flowering time. Here we study the phylogeny of AP2 group genes in spermatophytes. Spermatophyte AP2 group genes can be classified into AP2 and TOE types, six clades, and we found that the AP2 group homologs in gymnosperms belong to the AP2 type, whereas TOE types are absent, which indicates the AP2 type gene are more ancient and TOE type was split out of AP2 type and losing the major function. In Brassicaceae, the expansion of AP2 and TOE type lead to the gene number of AP2 group were up to six. Purifying selection appears to have been the primary driving force of spermatophyte AP2 group evolution, although positive selection occurred in the AP2 clade. The transition from exon to intron of AtAP2 in Arabidopsis mutant leads to the loss of gene function and the same situation was found in AtTOE2. Combining this evolutionary analysis and published research, the results suggest that typical AP2 group genes may first appear in gymnosperms and diverged in angiosperms, following expansion of group members and functional differentiation. In angiosperms, AP2 genes (AP2 clade) inherited key functions from ancestors and other genes of AP2 group lost most function but just remained flowering time controlling in gene formation. In this study, the phylogenies of AP2 group genes in spermatophytes was analyzed, which supported the evidence for the research of gene functional evolution of AP2 group.

  13. The role of glutathione in mercury tolerance resembles its function under cadmium stress in Arabidopsis.

    Science.gov (United States)

    Sobrino-Plata, Juan; Carrasco-Gil, Sandra; Abadía, Javier; Escobar, Carolina; Álvarez-Fernández, Ana; Hernández, Luis E

    2014-02-01

    Recent research efforts have highlighted the importance of glutathione (GSH) as a key antioxidant metabolite for metal tolerance in plants. Little is known about the mechanisms involved in stress due to mercury (Hg), one of the most hazardous metals to the environment and human health. To understand the implication of GSH metabolism for Hg tolerance, we used two γ-glutamylcysteine synthetase (γECS) Arabidopsis thaliana allele mutants (rax1-1 and cad2-1) and a phytochelatin synthase (PCS) mutant (cad1-3). The leaves of these mutants and of wild type (Col-0) were infiltrated with a solution containing Cd or Hg (0, 3 and 30 μM) and incubated for 24 and 48 h. The formation of phytochelatins (PCs) in the leaf extracts was followed by two different HPLC-based methods and occurred in Col-0, cad2-1 and rax1-1 plants exposed to Cd, whereas in the Hg treatments, PCs accumulated mainly in Col-0 and rax1-1, where Hg-PC complexes were also detected. ASA and GSH/GSSG levels increased under moderate metal stress conditions, accompanied by increased GSH reductase (GR) activity and expression. However, higher metal doses led to a decrease in the analysed parameters, and stronger toxic effects appeared with 30 μM Hg. The GSH concentration was significantly higher in rax1-1 (70% of Col-0) than in cad2-1 (40% of Col-0). The leaves of rax1-1 were less sensitive than cad2-1, in accordance with the greater expression of γECS in rax1-1. Our results underline the existence of a minimal GSH concentration threshold needed to minimise the toxic effects exerted by Hg.

  14. Functional screening of willow alleles in Arabidopsis combined with QTL mapping in willow (Salix) identifies SxMAX4 as a coppicing response gene.

    Science.gov (United States)

    Salmon, Jemma; Ward, Sally P; Hanley, Steven J; Leyser, Ottoline; Karp, Angela

    2014-05-01

    Willows (Salix spp.) are important biomass crops due to their ability to grow rapidly with low fertilizer inputs and ease of cultivation in short-rotation coppice cycles. They are relatively undomesticated and highly diverse, but functional testing to identify useful allelic variation is time-consuming in trees and transformation is not yet possible in willow. Arabidopsis is heralded as a model plant from which knowledge can be transferred to advance the improvement of less tractable species. Here, knowledge and methodologies from Arabidopsis were successfully used to identify a gene influencing stem number in coppiced willows, a complex trait of key biological and industrial relevance. The strigolactone-related More AXillary growth (MAX) genes were considered candidates due to their role in shoot branching. We previously demonstrated that willow and Arabidopsis show similar response to strigolactone and that transformation rescue of Arabidopsis max mutants with willow genes could be used to detect allelic differences. Here, this approach was used to screen 45 SxMAX1, SxMAX2, SxMAX3 and SxMAX4 alleles cloned from 15 parents of 11 mapping populations varying in shoot-branching traits. Single-nucleotide polymorphism (SNP) frequencies were locus dependent, ranging from 29.2 to 74.3 polymorphic sites per kb. SxMAX alleles were 98%-99% conserved at the amino acid level, but different protein products varying in their ability to rescue Arabidopsis max mutants were identified. One poor rescuing allele, SxMAX4D, segregated in a willow mapping population where its presence was associated with increased shoot resprouting after coppicing and colocated with a QTL for this trait.

  15. The ASK1 gene regulates B function gene expression in cooperation with UFO and LEAFY in Arabidopsis.

    Science.gov (United States)

    Zhao, D; Yu, Q; Chen, M; Ma, H

    2001-07-01

    The Arabidopsis floral regulatory genes APETALA3 (AP3) and PISTILLATA (PI) are required for the B function according to the ABC model for floral organ identity. AP3 and PI expression are positively regulated by the LEAFY (LFY) and UNUSUAL FLORAL ORGANS (UFO) genes. UFO encodes an F-box protein, and we have shown previously that UFO genetically interacts with the ASK1 gene encoding a SKP1 homologue; both the F-box containing protein and SKP1 are subunits of ubiquitin ligases. We show here that the ask1-1 mutation can enhance the floral phenotypes of weak lfy and ap3 mutants; therefore, like UFO, ASK1 also interacts with LFY and AP3 genetically. Furthermore, our results from RNA in situ hybridizations indicate that ASK1 regulates early AP3 and PI expression. These results support the idea that UFO and ASK1 together positively regulate AP3 and PI expression. We propose that the UFO and ASK1 proteins are components of a ubiquitin ligase that mediates the proteolysis of a repressor of AP3 and PI expression. Our genetic studies also indicate that ASK1 and UFO play a role in regulating the number of floral organ primordia, and we discuss possible mechanisms for such a regulation. PMID:11526079

  16. The ASK1 gene regulates B function gene expression in cooperation with UFO and LEAFY in Arabidopsis.

    Science.gov (United States)

    Zhao, D; Yu, Q; Chen, M; Ma, H

    2001-07-01

    The Arabidopsis floral regulatory genes APETALA3 (AP3) and PISTILLATA (PI) are required for the B function according to the ABC model for floral organ identity. AP3 and PI expression are positively regulated by the LEAFY (LFY) and UNUSUAL FLORAL ORGANS (UFO) genes. UFO encodes an F-box protein, and we have shown previously that UFO genetically interacts with the ASK1 gene encoding a SKP1 homologue; both the F-box containing protein and SKP1 are subunits of ubiquitin ligases. We show here that the ask1-1 mutation can enhance the floral phenotypes of weak lfy and ap3 mutants; therefore, like UFO, ASK1 also interacts with LFY and AP3 genetically. Furthermore, our results from RNA in situ hybridizations indicate that ASK1 regulates early AP3 and PI expression. These results support the idea that UFO and ASK1 together positively regulate AP3 and PI expression. We propose that the UFO and ASK1 proteins are components of a ubiquitin ligase that mediates the proteolysis of a repressor of AP3 and PI expression. Our genetic studies also indicate that ASK1 and UFO play a role in regulating the number of floral organ primordia, and we discuss possible mechanisms for such a regulation.

  17. Importance of post-translational modifications for functionality of a chloroplast-localized carbonic anhydrase (CAH1 in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Stefan Burén

    Full Text Available BACKGROUND: The Arabidopsis CAH1 alpha-type carbonic anhydrase is one of the few plant proteins known to be targeted to the chloroplast through the secretory pathway. CAH1 is post-translationally modified at several residues by the attachment of N-glycans, resulting in a mature protein harbouring complex-type glycans. The reason of why trafficking through this non-canonical pathway is beneficial for certain chloroplast resident proteins is not yet known. Therefore, to elucidate the significance of glycosylation in trafficking and the effect of glycosylation on the stability and function of the protein, epitope-labelled wild type and mutated versions of CAH1 were expressed in plant cells. METHODOLOGY/PRINCIPAL FINDINGS: Transient expression of mutant CAH1 with disrupted glycosylation sites showed that the protein harbours four, or in certain cases five, N-glycans. While the wild type protein trafficked through the secretory pathway to the chloroplast, the non-glycosylated protein formed aggregates and associated with the ER chaperone BiP, indicating that glycosylation of CAH1 facilitates folding and ER-export. Using cysteine mutants we also assessed the role of disulphide bridge formation in the folding and stability of CAH1. We found that a disulphide bridge between cysteines at positions 27 and 191 in the mature protein was required for correct folding of the protein. Using a mass spectrometric approach we were able to measure the enzymatic activity of CAH1 protein. Under circumstances where protein N-glycosylation is blocked in vivo, the activity of CAH1 is completely inhibited. CONCLUSIONS/SIGNIFICANCE: We show for the first time the importance of post-translational modifications such as N-glycosylation and intramolecular disulphide bridge formation in folding and trafficking of a protein from the secretory pathway to the chloroplast in higher plants. Requirements for these post-translational modifications for a fully functional native

  18. Functional analysis of Arabidopsis immune-related MAPKs uncovers a role for MPK3 as negative regulator of inducible defences

    KAUST Repository

    Frei dit Frey, Nicolas

    2014-06-30

    Background Mitogen-activated protein kinases (MAPKs) are key regulators of immune responses in animals and plants. In Arabidopsis, perception of microbe-associated molecular patterns (MAMPs) activates the MAPKs MPK3, MPK4 and MPK6. Increasing information depicts the molecular events activated by MAMPs in plants, but the specific and cooperative contributions of the MAPKs in these signalling events are largely unclear. Results In this work, we analyse the behaviour of MPK3, MPK4 and MPK6 mutants in early and late immune responses triggered by the MAMP flg22 from bacterial flagellin. A genome-wide transcriptome analysis reveals that 36% of the flg22-upregulated genes and 68% of the flg22-downregulated genes are affected in at least one MAPK mutant. So far MPK4 was considered as a negative regulator of immunity, whereas MPK3 and MPK6 were believed to play partially redundant positive functions in defence. Our work reveals that MPK4 is required for the regulation of approximately 50% of flg22-induced genes and we identify a negative role for MPK3 in regulating defence gene expression, flg22-induced salicylic acid accumulation and disease resistance to Pseudomonas syringae. Among the MAPK-dependent genes, 27% of flg22-upregulated genes and 76% of flg22-downregulated genes require two or three MAPKs for their regulation. The flg22-induced MAPK activities are differentially regulated in MPK3 and MPK6 mutants, both in amplitude and duration, revealing a highly interdependent network. Conclusions These data reveal a new set of distinct functions for MPK3, MPK4 and MPK6 and indicate that the plant immune signalling network is choreographed through the interplay of these three interwoven MAPK pathways.

  19. Expression analysis of Arabidopsis XH/XS-domain proteins indicates overlapping and distinct functions for members of this gene family.

    Science.gov (United States)

    Butt, Haroon; Graner, Sonja; Luschnig, Christian

    2014-03-01

    RNA-directed DNA methylation (RdDM) is essential for de novo DNA methylation in higher plants, and recent reports established novel elements of this silencing pathway in the model organism Arabidopsis thaliana. Involved in de novo DNA methylation 2 (IDN2) and the closely related factor of DNA methylation (FDM) are members of a plant-specific family of dsRNA-binding proteins characterized by conserved XH/XS domains and implicated in the regulation of RdDM at chromatin targets. Genetic analyses have suggested redundant as well as non-overlapping activities for different members of the gene family. However, detailed insights into the function of XH/XS-domain proteins are still elusive. By the generation and analysis of higher-order mutant combinations affected in IDN2 and further members of the gene family, we have provided additional evidence for their redundant activity. Distinct roles for members of the XH/XS-domain gene family were indicated by differences in their expression and subcellular localization. Fluorescent protein-tagged FDM genes were expressed either in nuclei or in the cytoplasm, suggestive of activities of XH/XS-domain proteins in association with chromatin as well as outside the nuclear compartment. In addition, we observed altered location of a functional FDM1-VENUS reporter from the nucleus into the cytoplasm under conditions when availability of further FDM proteins was limited. This is suggestive of a mechanism by which redistribution of XH/XS-domain proteins could compensate for the loss of closely related proteins.

  20. SCARECROW, SCR-LIKE 23 and SHORT-ROOT control bundle sheath cell fate and function in Arabidopsis thaliana.

    Science.gov (United States)

    Cui, Hongchang; Kong, Danyu; Liu, Xiuwen; Hao, Yueling

    2014-04-01

    Bundle sheath (BS) cells form a single cell layer surrounding the vascular tissue in leaves. In C3 plants, photosynthesis occurs in both the BS and mesophyll cells, but the BS cells are the major sites of photosynthesis in C4 plants, whereas the mesophyll cells are only involved in CO2 fixation. Because C4 plants are more efficient photosynthetically, introduction of the C4 mechanism into C3 plants is considered a key strategy to improve crop yield. One prerequisite for such C3-to-C4 engineering is the ability to manipulate the number and physiology of the BS cells, but the molecular basis of BS cell-fate specification remains unclear. Here we report that mutations in three GRAS family transcription factors, SHORT-ROOT (SHR), SCARECROW (SCR) and SCARECROW-LIKE 23 (SCL23), affect BS cell fate in Arabidopsis thaliana. SCR and SCL23 are expressed specifically in the BS cells and act redundantly in BS cell-fate specification, but their expression pattern and function diverge at later stages of leaf development. Using ChIP-chip experiments and sugar assays, we show that SCR is primarily involved in sugar transport whereas SCL23 functions in mineral transport. SHR is also essential for BS cell-fate specification, but it is expressed in the central vascular tissue. However, the SHR protein moves into the BS cells, where it directly regulates SCR and SCL23 expression. SHR, SCR and SCL23 homologs are present in many plant species, suggesting that this developmental pathway for BS cell-fate specification is likely to be evolutionarily conserved.

  1. Functional conservation of rice OsNF-YB/YC and Arabidopsis AtNF-YB/YC proteins in the regulation of flowering time

    KAUST Repository

    Hwang, Yoon-Hyung

    2016-01-11

    Plant NUCLEAR FACTOR Y (NF-Y) transcription factors play important roles in plant development and abiotic stress. In Arabidopsis thaliana, two NF-YB (AtNF-YB2 and AtNF-YB3) and five NF-YC (AtNF-YC1, AtNF-YC2, AtNF-YC3, AtNF-YC4, and AtNF-YC9) genes regulate photoperiodic flowering by interacting with other AtNF-Y subunit proteins. Three rice NF-YB (OsNF-YB8, OsNF-YB10, and OsNF-YB11) and five rice OsNF-YC (OsNF-YC1, OsNF-YC2, OsNF-YC4, OsNF-YC6, and OsNF-YC7) genes are clustered with two AtNF-YB and five AtNF-YC genes, respectively. To investigate the functional conservation of these NF-YB and NF-YC genes in rice and Arabidopsis, we analyzed the flowering phenotypes of transgenic plants overexpressing the respective OsNF-YB and OsNF-YC genes in Arabidopsis mutants. Overexpression of OsNF-YB8/10/11 and OsNF-YC2 complemented the late flowering phenotype of Arabidopsis nf-yb2 nf-yb3 and nf-yc3 nf-yc4 nf-yc9 mutants, respectively. The rescued phenotype of 35S::OsNF-YC2 nf-yc3 nf-yc4 nf-yc9 plants was attributed to the upregulation of FLOWERING LOCUS T (FT) and SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1 (SOC1). In vitro and in planta protein–protein analyses revealed that OsNF-YB8/10/11 and OsNF-YC1/2/4/6/7 interact with AtNF-YC3/4/9 and AtNF-YB2/3, respectively. Our data indicate that some OsNF-YB and OsNF-YC genes are functional equivalents of AtNF-YB2/3 and AtNF-YC3/4/9 genes, respectively, and suggest functional conservation of Arabidopsis and rice NF-Y genes in the control of flowering time.

  2. Characterization of an Arabidopsis-Phytophthora pathosystem: resistance requires a functional PAD2 gene and is independent of salicylic acid, ethylene and jasmonic acid signalling.

    Science.gov (United States)

    Roetschi, A; Si-Ammour, A; Belbahri, L; Mauch, F; Mauch-Mani, B

    2001-11-01

    Arabidopsis accessions were screened with isolates of Phytophthora porri originally isolated from other crucifer species. The described Arabidopsis-Phytophthora pathosystem shows the characteristics of a facultative biotrophic interaction similar to that seen in agronomically important diseases caused by Phytophthora species. In susceptible accessions, extensive colonization of the host tissue occurred and sexual and asexual spores were formed. In incompatible combinations, the plants reacted with a hypersensitive response (HR) and the formation of papillae at the sites of attempted penetration. Defence pathway mutants such as jar1 (jasmonic acid-insensitive), etr1 (ethylene receptor mutant) and ein2 (ethylene-insensitive) remained resistant towards P. porri. However, pad2, a mutant with reduced production of the phytoalexin camalexin, was hyper-susceptible. The accumulation of salicylic acid (SA) and PR1 protein was strongly reduced in pad2. Surprisingly, this lack of SA accumulation does not appear to be the cause of the hyper-susceptibility because interference with SA signalling in nahG plants or sid2 or npr1 mutants had only a minor effect on resistance. In addition, the functional SA analogue benzothiadiazol (BTH) did not induce resistance in susceptible plants including pad2. Similarly, the complete blockage of camalexin biosynthesis in pad3 did not cause susceptibility. Resistance of Arabidopsis against P. porri appears to depend on unknown defence mechanisms that are under the control of PAD2.

  3. Molecular Genetic Analysis of Glucan Branching Enzymes from Plants and Bacteria in Arabidopsis Reveals Marked Differences in Their Functions and Capacity to Mediate Starch Granule Formation.

    Science.gov (United States)

    Lu, Kuan-Jen; Streb, Sebastian; Meier, Florence; Pfister, Barbara; Zeeman, Samuel C

    2015-11-01

    The major component of starch is the branched glucan amylopectin, the branching pattern of which is one of the key factors determining its ability to form semicrystalline starch granules. Here, we investigated the functions of different branching enzyme (BE) types by expressing proteins from maize (Zea mays BE2a), potato (Solanum tuberosum BE1), and Escherichia coli (glycogen BE [EcGLGB]) in Arabidopsis (Arabidopsis thaliana) mutant plants that are deficient in their endogenous BEs and therefore, cannot make starch. The expression of each of these three BE types restored starch biosynthesis to differing degrees. Full complementation was achieved using the class II BE ZmBE2a, which is most similar to the two endogenous Arabidopsis isoforms. Expression of the class I BE from potato, StBE1, resulted in partial complementation and high amylose starch. Expression of the glycogen BE EcGLGB restored only minimal amounts of starch production, which had unusual chain length distribution, branch point distribution, and granule morphology. Nevertheless, each type of BE together with the starch synthases and debranching enyzmes were able to create crystallization-competent amylopectin polymers. These data add to the knowledge of how the properties of the BE influence the final composition of starch and fine structure of amylopectin. PMID:26358415

  4. Gene Expression, Protein Function and Pathways of Arabidopsis thaliana Responding to Silver Nanoparticles in Comparison to Silver Ions, Cold, Salt, Drought, and Heat

    Directory of Open Access Journals (Sweden)

    Eisa Kohan-Baghkheirati

    2015-03-01

    Full Text Available Silver nanoparticles (AgNPs have been widely used in industry due to their unique physical and chemical properties. However, AgNPs have caused environmental concerns. To understand the risks of AgNPs, Arabidopsis microarray data for AgNP, Ag+, cold, salt, heat and drought stresses were analyzed. Up- and down-regulated genes of more than two-fold expression change were compared, while the encoded proteins of shared and unique genes between stresses were subjected to differential enrichment analyses. AgNPs affected the fewest genes (575 in the Arabidopsis genome, followed by Ag+ (1010, heat (1374, drought (1435, salt (4133 and cold (6536. More genes were up-regulated than down-regulated in AgNPs and Ag+ (438 and 780, respectively while cold down-regulated the most genes (4022. Responses to AgNPs were more similar to those of Ag+ (464 shared genes, cold (202, and salt (163 than to drought (50 or heat (30; the genes in the first four stresses were enriched with 32 PFAM domains and 44 InterPro protein classes. Moreover, 111 genes were unique in AgNPs and they were enriched in three biological functions: response to fungal infection, anion transport, and cell wall/plasma membrane related. Despite shared similarity to Ag+, cold and salt stresses, AgNPs are a new stressor to Arabidopsis.

  5. The ARG1-LIKE2 gene of Arabidopsis functions in a gravity signal transduction pathway that is genetically distinct from the PGM pathway

    Science.gov (United States)

    Guan, Changhui; Rosen, Elizabeth S.; Boonsirichai, Kanokporn; Poff, Kenneth L.; Masson, Patrick H.

    2003-01-01

    The arl2 mutants of Arabidopsis display altered root and hypocotyl gravitropism, whereas their inflorescence stems are fully gravitropic. Interestingly, mutant roots respond like the wild type to phytohormones and an inhibitor of polar auxin transport. Also, their cap columella cells accumulate starch similarly to wild-type cells, and mutant hypocotyls display strong phototropic responses to lateral light stimulation. The ARL2 gene encodes a DnaJ-like protein similar to ARG1, another protein previously implicated in gravity signal transduction in Arabidopsis seedlings. ARL2 is expressed at low levels in all organs of seedlings and plants. arl2-1 arg1-2 double mutant roots display kinetics of gravitropism similar to those of single mutants. However, double mutants carrying both arl2-1 and pgm-1 (a mutation in the starch-biosynthetic gene PHOSPHOGLUCOMUTASE) at the homozygous state display a more pronounced root gravitropic defect than the single mutants. On the other hand, seedlings with a null mutation in ARL1, a paralog of ARG1 and ARL2, behave similarly to the wild type in gravitropism and other related assays. Taken together, the results suggest that ARG1 and ARL2 function in the same gravity signal transduction pathway in the hypocotyl and root of Arabidopsis seedlings, distinct from the pathway involving PGM.

  6. Functional identification of an Arabidopsis snf4 ortholog by screening for heterologous multicopy suppressors of snf4 deficiency in yeast

    DEFF Research Database (Denmark)

    Kleinow, T.; Bhalerao, R.; Breuer, F.;

    2000-01-01

    Yeast Snf4 is a prototype of activating gamma-subunits of conserved Snf1/AMPK-related protein kinases (SnRKs) controlling glucose and stress signaling in eukaryotes. The catalytic subunits of Arabidopsis SnRKs, AKIN10 and AKIN11, interact with Snf4 and suppress the snf1 and snf4 mutations in yeast....... By expression of an Arabidopsis cDNA library in yeast, heterologous multicopy snf4 suppressors were isolated. In addition to AKIN10 and AKIN11, the deficiency of yeast snf4 mutant to grown on non-fermentable carbon source was suppressed by Arabidopsis Myb30, CAAT-binding factor Hap3b, casein kinase I, zinc...

  7. Major latex protein-like protein 43 (MLP43) functions as a positive regulator during abscisic acid responses and confers drought tolerance in Arabidopsis thaliana.

    Science.gov (United States)

    Wang, Yanping; Yang, Li; Chen, Xi; Ye, Tiantian; Zhong, Bao; Liu, Ruijie; Wu, Yan; Chan, Zhulong

    2016-01-01

    Drought stress is one of the disadvantageous environmental conditions for plant growth and reproduction. Given the importance of abscisic acid (ABA) to plant growth and abiotic stress responses, identification of novel components involved in ABA signalling transduction is critical. In this study, we screened numerous Arabidopsis thaliana mutants by seed germination assay and identified a mutant mlp43 (major latex protein-like 43) with decreased ABA sensitivity in seed germination. The mlp43 mutant was sensitive to drought stress while the MLP43-overexpressed transgenic plants were drought tolerant. The tissue-specific expression pattern analysis showed that MLP43 was predominantly expressed in cotyledons, primary roots and apical meristems, and a subcellular localization study indicated that MLP43 was localized in the nucleus and cytoplasm. Physiological and biochemical analyses indicated that MLP43 functioned as a positive regulator in ABA- and drought-stress responses in Arabidopsis through regulating water loss efficiency, electrolyte leakage, ROS levels, and as well as ABA-responsive gene expression. Moreover, metabolite profiling analysis indicated that MLP43 could modulate the production of primary metabolites under drought stress conditions. Reconstitution of ABA signalling components in Arabidopsis protoplasts indicated that MLP43 was involved in ABA signalling transduction and acted upstream of SnRK2s by directly interacting with SnRK2.6 and ABF1 in a yeast two-hybrid assay. Moreover, ABA and drought stress down-regulated MLP43 expression as a negative feedback loop regulation to the performance of MLP43 in ABA and drought stress responses. Therefore, this study provided new insights for interpretation of physiological and molecular mechanisms of Arabidopsis MLP43 mediating ABA signalling transduction and drought stress responses.

  8. The AP-3 adaptor complex is required for vacuolar function in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Maria Zwiewka; Elena Feraru; Barbara M(o)ller; Inhwan Hwang; Mugurel I Feraru; Jürgen Kleine-Vehn; Dolf Weijers; Ji(n) Friml

    2011-01-01

    Subcellular trafficking is required for a multitude of functions in eukaryotic cells.It involves regulation of cargo sorting,vesicle formation,trafficking and fusion processes at multiple levels.Adaptor protein (AP) complexes are key regulators of cargo sorting into vesicles in yeast and mammals but their existence and function in plants have not been demonstrated.Here we report the identification of the protein-affected trafficking 4 (pat4) mutant defective in the putative δ subunit of the AP-3 complex.pat4 and pat2,a mutant isolated from the same GFP imaging-based forward genetic screen that lacks a functional putative AP-3 β,as well as dominant negative AP-3 μ transgenic lines display undistinguishable phenotypes characterized by largely normal morphology and development,but strong intracellular accumulation of membrane proteins in aberrant vacuolar structures.All mutants are defective in morphology and function of lytic and protein storage vacuoles (PSVs) but show normal sorting of reserve proteins to PSVs.Immunoprecipitation experiments and genetic studies revealed tight functional and physical associations of putative AP-3 β and AP-3 δ subunits.Furthermore,both proteins are closely linked with putative AP-3 μ and σ subunits and several components of the clathrin and dynamin machineries.Taken together,these results demonstrate that AP complexes,similar to those in other eukaryotes,exist in plants,and that AP-3 plays a specific role in the regulation of biogenesis and function of vacuoles in plant cells.

  9. The AP-3 adaptor complex is required for vacuolar function in Arabidopsis

    NARCIS (Netherlands)

    Zwiewka, M.; Feraru, E.; Moller, B.K.; Hwang, I.; Feraru, M.I.; Kleine-Vehn, J.; Weijers, D.; Friml, J.

    2011-01-01

    Subcellular trafficking is required for a multitude of functions in eukaryotic cells. It involves regulation of cargo sorting, vesicle formation, trafficking and fusion processes at multiple levels. Adaptor protein (AP) complexes are key regulators of cargo sorting into vesicles in yeast and mammals

  10. A rapid and efficient method to study the function of crop plant transporters in Arabidopsis

    Science.gov (United States)

    Iron (Fe) is an essential micronutrient for humans. Fe deficiency disease is wide-spread and has lead to extensive studies on the mechanisms of Fe uptake and storage, especially in staple food crops such as rice. However, studies of functionally related genes in rice and other crops are often time a...

  11. AXL and AXR1 have redundant functions in RUB conjugation and growth and development in Arabidopsis.

    NARCIS (Netherlands)

    Dharmasiri, N.; Dharmasiri, S.; Weijers, D.; Karunaratha, N.; Juergens, G.; Estelle, M.

    2007-01-01

    Cullin-RING ubiquitin-protein ligases such as the Skp1, cullin, F-box protein (SCF) have been implicated in many growth and developmental processes in plants. Normal SCF function requires that the CUL1 subunit be post-translationally modified by related to ubiquitin (RUB), a protein related to ubiqu

  12. The Arabidopsis thaliana brassinosteroid receptor (AtBRI1 contains a domain that functions as a guanylyl cyclase in vitro.

    Directory of Open Access Journals (Sweden)

    Lusisizwe Kwezi

    Full Text Available BACKGROUND: Guanylyl cyclases (GCs catalyze the formation of the second messenger guanosine 3',5'-cyclic monophosphate (cGMP from guanosine 5'-triphosphate (GTP. Cyclic GMP has been implicated in an increasing number of plant processes, including responses to abiotic stresses such as dehydration and salt, as well as hormones. PRINCIPLE FINDINGS: Here we used a rational search strategy based on conserved and functionally assigned residues in the catalytic centre of annotated GCs to identify candidate GCs in Arabidopsis thaliana and show that one of the candidates is the brassinosteroid receptor AtBR1, a leucine rich repeat receptor like kinase. We have cloned and expressed a 114 amino acid recombinant protein (AtBR1-GC that harbours the putative catalytic domain, and demonstrate that this molecule can convert GTP to cGMP in vitro. CONCLUSIONS: Our results suggest that AtBR1 may belong to a novel class of GCs that contains both a cytosolic kinase and GC domain, and thus have a domain organisation that is not dissimilar to that of atrial natriuretic peptide receptors, NPR1 and NPR2. The findings also suggest that cGMP may have a role as a second messenger in brassinosteroid signalling. In addition, it is conceivable that other proteins containing the extended GC search motif may also have catalytic activity, thus implying that a significant number of GCs, both in plants and animals, remain to be discovered, and this is in keeping with the fact that the single cellular green alga Chlamydomonas reinhardtii contains over 90 annotated putative CGs.

  13. SPATULA and ALCATRAZ, are partially redundant, functionally diverging bHLH genes required for Arabidopsis gynoecium and fruit development.

    Science.gov (United States)

    Groszmann, Michael; Paicu, Teodora; Alvarez, John P; Swain, Steve M; Smyth, David R

    2011-12-01

    The Arabidopsis gynoecium is a complex organ that facilitates fertilization, later developing into a dehiscent silique that protects seeds until their dispersal. Identifying genes important for development is often hampered by functional redundancy. We report unequal redundancy between two closely related genes, SPATULA (SPT) and ALCATRAZ (ALC), revealing previously unknown developmental roles for each. SPT is known to support septum, style and stigma development in the flower, whereas ALC is involved in dehiscence zone development in the fruit. ALC diverged from a SPT-like ancestor following gene duplication coinciding with the At-β polyploidy event. Here we show that ALC is also involved in early gynoecium development, and SPT in later valve margin generation in the silique. Evidence includes the increased severity of early gynoecium disruption, and of later valve margin defects, in spt-alc double mutants. In addition, a repressive version of SPT (35S:SPT-SRDX) disrupts both structures. Consistent with redundancy, ALC and SPT expression patterns overlap in these tissues, and the ALC promoter carries two atypical E-box elements identical to one in SPT required for valve margin expression. Further, SPT can heterodimerize with ALC, and 35S:SPT can fully complement dehiscence defects in alc mutants, although 35S:ALC can only partly complement spt gynoecium disruptions, perhaps associated with its sequence simplification. Interactions with FRUITFULL and SHATTERPROOF genes differ somewhat between SPT and ALC, reflecting their different specializations. These two genes are apparently undergoing subfunctionalization, with SPT essential for earlier carpel margin tissues, and ALC specializing in later dehiscence zone development. PMID:21801252

  14. CYP79F1 and CYP79F2 have distinct functions in the biosynthesis of aliphatic glucosinolates in Arabidopsis.

    Science.gov (United States)

    Chen, Sixue; Glawischnig, Erich; Jørgensen, Kirsten; Naur, Peter; Jørgensen, Bodil; Olsen, Carl-Erik; Hansen, Carsten H; Rasmussen, Hasse; Pickett, John A; Halkier, Barbara A

    2003-03-01

    Cytochromes P450 of the CYP79 family catalyze the conversion of amino acids to oximes in the biosynthesis of glucosinolates, a group of natural plant products known to be involved in plant defense and as a source of flavor compounds, cancer-preventing agents and bioherbicides. We report a detailed biochemical analysis of the substrate specificity and kinetics of CYP79F1 and CYP79F2, two cytochromes P450 involved in the biosynthesis of aliphatic glucosinolates in Arabidopsis thaliana. Using recombinant CYP79F1 and CYP79F2 expressed in Escherichia coli and Saccharomyces cerevisiae, respectively, we show that CYP79F1 metabolizes mono- to hexahomomethionine, resulting in both short- and long-chain aliphatic glucosinolates. In contrast, CYP79F2 exclusively metabolizes long-chain elongated penta- and hexahomomethionines. CYP79F1 and CYP79F2 are spatially and developmentally regulated, with different gene expression patterns. CYP79F2 is highly expressed in hypocotyl and roots, whereas CYP79F1 is strongly expressed in cotyledons, rosette leaves, stems, and siliques. A transposon-tagged CYP79F1 knockout mutant completely lacks short-chain aliphatic glucosinolates, but has an increased level of long-chain aliphatic glucosinolates, especially in leaves and seeds. The level of long-chain aliphatic glucosinolates in a transposon-tagged CYP79F2 knockout mutant is substantially reduced, whereas the level of short-chain aliphatic glucosinolates is not affected. Biochemical characterization of CYP79F1 and CYP79F2, and gene expression analysis, combined with glucosinolate profiling of knockout mutants demonstrate the functional role of these enzymes. This provides valuable insights into the metabolic network leading to the biosynthesis of aliphatic glucosinolates, and into metabolic engineering of altered aliphatic glucosinolate profiles to improve nutritional value and pest resistance. PMID:12609033

  15. A Genome-wide Functional Characterization of Arabidopsis Regulatory Calcium Sensors in Pollen Tubes

    Institute of Scientific and Technical Information of China (English)

    Liming Zhou; Ying FU; Zhenbiao Yang

    2009-01-01

    Calcium, an ubiquitous second messenger, plays an essential and versatile role in cellular signaling. The diverse function of calcium signals is achieved by an excess of calcium sensors. Plants possess large numbers of calcium sensors, most of which have not been functionally characterized. To identify physiologically relevant calcium sensors in a specific cell type, we conducted a genome-wide functional survey in pollen tubes, for which spatiotemporal calcium signals are well-characterized and required for polarized tip growth. Pollen-specific members of calmodulin (CAM), CaM-like (CML), calcium-dependent protein kinase (CDPK) and calcineurin B-like protein (CBL) families were tagged with green fluorescence protein (GFP) and their localization patterns and overexpression phenotypes were characterized in tobacco pollen tubes. We found that several fusion proteins showed distinct overexpression phenotypes and subcellular localization patterns. CDPK24.GFP was localized to the vegetative nucleus and the generative cell/sperms. CDPK32-GFP caused severe growth depolarization. CBL2-GFP and CBL3-GFP exhibited dynamic patterns of subcellular localization, including several endomembrane compartments, the apical plasma membrane (PM), and cytoskeleton-like structures in pollen tubes. Their overexpression also inhibited pollen tube elongation and induced growth depolarization. These putative calcium sensors are excellent candidates for the calcium sensors responsible for the regulation of calcium homeostasis and calcium-dependent tip growth and growth oscillation in pollen tubes,

  16. Overlapping functions of the starch synthases SSII and SSIII in amylopectin biosynthesis in Arabidopsis

    Directory of Open Access Journals (Sweden)

    D'Hulst Christophe

    2008-09-01

    Full Text Available Abstract Background The biochemical mechanisms that determine the molecular architecture of amylopectin are central in plant biology because they allow long-term storage of reduced carbon. Amylopectin structure imparts the ability to form semi-crystalline starch granules, which in turn provides its glucose storage function. The enzymatic steps of amylopectin biosynthesis resemble those of the soluble polymer glycogen, however, the reasons for amylopectin's architectural distinctions are not clearly understood. The multiplicity of starch biosynthetic enzymes conserved in plants likely is involved. For example, amylopectin chain elongation in plants involves five conserved classes of starch synthase (SS, whereas glycogen biosynthesis typically requires only one class of glycogen synthase. Results Null mutations were characterized in AtSS2, which codes for SSII, and mutant lines were compared to lines lacking SSIII and to an Atss2, Atss3 double mutant. Loss of SSII did not affect growth rate or starch quantity, but caused increased amylose/amylopectin ratio, increased total amylose, and deficiency in amylopectin chains with degree of polymerization (DP 12 to DP28. In contrast, loss of both SSII and SSIII caused slower plant growth and dramatically reduced starch content. Extreme deficiency in DP12 to DP28 chains occurred in the double mutant, far more severe than the summed changes in SSII- or SSIII-deficient plants lacking only one of the two enzymes. Conclusion SSII and SSIII have partially redundant functions in determination of amylopectin structure, and these roles cannot be substituted by any other conserved SS, specifically SSI, GBSSI, or SSIV. Even though SSIII is not required for the normal abundance of glucan chains of DP12 to DP18, the enzyme clearly is capable of functioning in production such chains. The role of SSIII in producing these chains cannot be detected simply by analysis of an individual mutation. Competition between

  17. The mitochondrial protease AtFTSH4 safeguards Arabidopsis shoot apical meristem function.

    Science.gov (United States)

    Dolzblasz, Alicja; Smakowska, Elwira; Gola, Edyta M; Sokołowska, Katarzyna; Kicia, Marta; Janska, Hanna

    2016-06-20

    The shoot apical meristem (SAM) ensures continuous plant growth and organogenesis. In LD 30 °C, plants lacking AtFTSH4, an ATP-dependent mitochondrial protease that counteracts accumulation of internal oxidative stress, exhibit a puzzling phenotype of premature SAM termination. We aimed to elucidate the underlying cellular and molecular processes that link AtFTSH4 with SAM arrest. We studied AtFTSH4 expression, internal oxidative stress accumulation, and SAM morphology. Directly in the SAM we analysed H2O2 accumulation, mitochondria behaviour, and identity of stem cells using WUS/CLV3 expression. AtFTSH4 was expressed in proliferating tissues, particularly during the reproductive phase. In the mutant, SAM, in which internal oxidative stress accumulates predominantly at 30 °C, lost its meristematic fate. This process was progressive and stage-specific. Premature meristem termination was associated with an expansion in SAM area, where mitochondria lost their functionality. All these effects destabilised the identity of the stem cells. SAM termination in ftsh4 mutants is caused both by internal oxidative stress accumulation with time/age and by the tissue-specific role of AtFTSH4 around the flowering transition. Maintaining mitochondria functionality within the SAM, dependent on AtFTSH4, is vital to preserving stem cell activity throughout development.

  18. Arabidopsis TT19 Functions as a Carrier to Transport Anthocyanin from the Cytosol to Tonoplasts

    Institute of Scientific and Technical Information of China (English)

    Yi Sun; Hong Li; Ji-Rong Huang

    2012-01-01

    Anthocyanins are synthesized in the cytosolic surface of the endoplasmic reticulum (ER) but dominantly accumulate in the vacuole.Little is known about how anthocyanins are transported from the ER to the vacuole.Here,we provide evidence supporting that Transparent Testa 19 (TT19),a glutathione S-transferase (GST),functions as a carrier to transport cyanidin and/or anthocyanins to the tonoplast.We identified a novel tt19 mutant (tt19-7),which barely accumulates anthocyanins but produces a 36% higher level of flavonol than the wild-type (WT),from ethyl methanesulfonate mutagenized seeds.Expressing TT19-fused green fluorescence protein (GFP) in tt19-7 rescues the mutant phenotype in defective anthocyanin biosynthesis,indicating that TT19-GFP is functional.We further showed that TT19-GFP is localized not only in the cytoplasm and nuclei,but also on the tonoplast.The membrane localization of TT19-GFP was further ascertained by immunoblot analysis.In vitro assay showed that the purified recombinant TT19 increases water solubility of cyanidin (Cya) and cyanidin-3-O-glycoside (C3G).Compared with C3G,Cya can dramatically quench the intrinsic tryptophan fluorescence of TT19 to much lower levels,indicating a higher affinity of TT19 to Cya than to C3G.Isothermal titration calorimetry analysis also confirmed physical interaction between TT19 and C3G.Taken together,our data reveal molecular mechanism underlying TT19-mediated anthocyanin transportation.

  19. Universal Stress Protein exhibits a redox-dependent chaperone function in Arabidopsis and enhances plant tolerance to heat shock and oxidative stress

    Directory of Open Access Journals (Sweden)

    Jung eYoung Jun

    2015-12-01

    Full Text Available Although a wide range of physiological information on Universal Stress Proteins (USPs is available from many organisms, their biochemical and molecular functions remain unidentified. The biochemical function of AtUSP (At3g53990 from Arabidopsis thaliana was therefore investigated. Plants over-expressing AtUSP showed a strong resistance to heat shock and oxidative stress, compared with wild-type and Atusp knock-out plants, confirming the crucial role of AtUSP in stress tolerance. AtUSP was present in a variety of structures including monomers, dimers, trimers, and oligomeric complexes, and switched in response to external stresses from low molecular weight (LMW species to high molecular weight (HMW complexes. AtUSP exhibited a strong chaperone function under stress conditions in particular, and this activity was significantly increased by heat treatment. Chaperone activity of AtUSP was critically regulated by the redox status of cells and accompanied by structural changes to the protein. Over-expression of AtUSP conferred a strong tolerance to heat shock and oxidative stress upon Arabidopsis, primarily via its chaperone function.

  20. Mitochondrial Sulfide Detoxification Requires a Functional Isoform O-Acetylserine(thiol)lyase C in Arabidopsis thaliana

    Institute of Scientific and Technical Information of China (English)

    Consolación (A)lvarez; Irene García; Luis C.Romero; Cecilia Gotor

    2012-01-01

    In non-cyanogenic species,the main source of cyanide derives from ethylene and camalexin biosyntheses.In mitochondria,cyanide is a potent inhibitor of the cytochrome c oxidase and is metabolized bythe β-cyanoalanine synthase CYS-C1,catalyzing the conversion of cysteine and cyanide to hydrogen sulfide and β-cyanoalanine.The hydrogen sulfide released also inhibits the cytochrome c oxidase and needs to be detoxified by the O-acetylserine(thiol)lyase mitochondrial isoform,OAS-C,which catalyzes the incorporation of sulfide to O-acetylserine to produce cysteine,thus generating a cyclic pathway in the mitochondria.The loss of functional OAS-C isoforms causes phenotypic characteristics very similar to the loss of the CYS-C1 enzyme,showing defects in root hair formation.Genetic complementation with the OAS-C gene rescues the impairment of root hair elongation,restoring the wild-type phenotype.The mitochondria compromise their capacity to properly detoxify cyanide and the resulting sulfide because the latter cannot re-assimilate into cysteine in the oas-c null mutant.Consequently,we observe an accumulation of sulfide and cyanide and of the alternative oxidase,which is unable to prevent the production of reactive oxygen species probably due to the accumulation of both toxic molecules.Our results allow us to suggest that the significance of OAS-C is related to its role in the proper sulfide and cyanide detoxification in mitochondria.

  1. Quantitative Changes in Microtubule Distribution Correlate with Guard Cell Function in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    William R. Eisinger; Viktor Kirik; Charlotte Lewis; David W. Ehrhardt; Winslow R. Briggs

    2012-01-01

    Radially arranged cortical microtubules are a prominent feature of guard cells.We observed guard cells expressing GFP-tubulin (GFP-TUA6) with confocal microscopy and found recognizable changes in the appearance of microtubules when stomata open or close (Eisinger et al.,2012).In the present study,analysis of fluorescence distribution showed a dramatic increase in peak intensities of microtubule bundles within guard cells as stomata open.This increase was correlated with an increase in the total fluorescence that could be attributed to polymerized tubulin.Adjacent pavement cells did not show similar changes in peak intensities or integrated fluorescence when stomatal apertures changed.Imaging of RFP-tagged end binding protein 1 (EB1) and YFP-tagged α-tubulin expressed in the same cell revealed that the number of microtubules with growing ends remained constant,although the total amount of polymerized tubulin was higher in open than in closed guard cells.Taken together,these results indicate that the changes in microtubule array organization that are correlated with and required for normal guard cell function are characterized by changes in microtubule clustering or bundling.

  2. SHA1, a novel RING finger protein, functions in shoot apical meristem maintenance in Arabidopsis.

    Science.gov (United States)

    Sonoda, Yutaka; Yao, Shan-Guo; Sako, Kaori; Sato, Takeo; Kato, Wataru; Ohto, Masa-aki; Ichikawa, Takanari; Matsui, Minami; Yamaguchi, Junji; Ikeda, Akira

    2007-05-01

    Post-embryonic plant growth is dependent on a functional shoot apical meristem (SAM) that provides cells for continuous development of new aerial organs. However, how the SAM is dynamically maintained during vegetative development remains largely unclear. We report here the characterization of a new SAM maintenance mutant, sha1-1 (shoot apical meristem arrest 1-1), that shows a primary SAM-deficient phenotype at the adult stage. The SHA1 gene encodes a novel RING finger protein, and is expressed most intensely in the shoot apex. We show that, in the sha1-1 mutant, the primary SAM develops normally during the juvenile vegetative stage, but cell layer structure becomes disorganized after entering the adult vegetative stage, resulting in a dysfunctional SAM that cannot initiate floral primordia. The sha1-1 SAM terminates completely at the stage when the wild-type begins to bolt, producing adult plants with a primary inflorescence-deficient phenotype. These observations indicate that SHA1, a putative E3 ligase, is required for post-embryonic SAM maintenance by controlling proper cellular organization. PMID:17461786

  3. The functional interplay between protein kinase CK2 and CCA1 transcriptional activity is essential for clock temperature compensation in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Sergi Portolés

    2010-11-01

    Full Text Available Circadian rhythms are daily biological oscillations driven by an endogenous mechanism known as circadian clock. The protein kinase CK2 is one of the few clock components that is evolutionary conserved among different taxonomic groups. CK2 regulates the stability and nuclear localization of essential clock proteins in mammals, fungi, and insects. Two CK2 regulatory subunits, CKB3 and CKB4, have been also linked with the Arabidopsis thaliana circadian system. However, the biological relevance and the precise mechanisms of CK2 function within the plant clockwork are not known. By using ChIP and Double-ChIP experiments together with in vivo luminescence assays at different temperatures, we were able to identify a temperature-dependent function for CK2 modulating circadian period length. Our study uncovers a previously unpredicted mechanism for CK2 antagonizing the key clock regulator CIRCADIAN CLOCK-ASSOCIATED 1 (CCA1. CK2 activity does not alter protein accumulation or subcellular localization but interferes with CCA1 binding affinity to the promoters of the oscillator genes. High temperatures enhance the CCA1 binding activity, which is precisely counterbalanced by the CK2 opposing function. Altering this balance by over-expression, mutation, or pharmacological inhibition affects the temperature compensation profile, providing a mechanism by which plants regulate circadian period at changing temperatures. Therefore, our study establishes a new model demonstrating that two opposing and temperature-dependent activities (CCA1-CK2 are essential for clock temperature compensation in Arabidopsis.

  4. The TORNADO1 and TORNADO2 genes function in several patterning processes during early leaf development in Arabidopsis thaliana

    OpenAIRE

    Cnops, Gerda; Neyt, Pia; Raes, Jeroen; Petrarulo, Marica; Nelissen, Hilde; Malenica, Nenad; Luschnig, Christian; Tietz, Olaf; Ditengou, Franck; Palme, Klaus; Azmi, Abdelkrim; Prinsen, Els; Van Lijsebettens, Maria

    2006-01-01

    In multicellular organisms, patterning is a process that generates axes in the primary body plan, creates domains upon organ formation, and finally leads to differentiation into tissues and cell types. We identified the Arabidopsis thaliana TORNADO1 (TRN1) and TRN2 genes and their role in leaf patterning processes such as lamina venation, symmetry, and lateral growth. In trn mutants, the leaf venation network had a severely reduced complexity: incomplete loops, no tertiary or quaternary veins...

  5. Arabidopsis acyl-acyl carrier protein synthetase AAE15 with medium chain fatty acid specificity is functional in cyanobacteria

    OpenAIRE

    Kaczmarzyk, Danuta; Hudson, Elton P.; Fulda, Martin

    2016-01-01

    Cyanobacteria are potential hosts for the biosynthesis of oleochemical compounds. The metabolic precursors for such compounds are fatty acids and their derivatives, which require chemical activation to become substrates in further conversion steps. We characterized the acyl activating enzyme AAE15 of Arabidopsis encoded by At4g14070, which is a homologue of a cyanobacterial acyl-ACP synthetase (AAS). We expressed AAE15 in insect cells and demonstrated its AAS activity with medium chain fatty ...

  6. Transgenerational adaptation of Arabidopsis to stress requires DNA methylation and the function of Dicer-like proteins.

    Directory of Open Access Journals (Sweden)

    Alex Boyko

    Full Text Available Epigenetic states and certain environmental responses in mammals and seed plants can persist in the next sexual generation. These transgenerational effects have potential adaptative significance as well as medical and agronomic ramifications. Recent evidence suggests that some abiotic and biotic stress responses of plants are transgenerational. For example, viral infection of tobacco plants and exposure of Arabidopsis thaliana plants to UVC and flagellin can induce transgenerational increases in homologous recombination frequency (HRF. Here we show that exposure of Arabidopsis plants to stresses, including salt, UVC, cold, heat and flood, resulted in a higher HRF, increased global genome methylation, and higher tolerance to stress in the untreated progeny. This transgenerational effect did not, however, persist in successive generations. Treatment of the progeny of stressed plants with 5-azacytidine was shown to decrease global genomic methylation and enhance stress tolerance. Dicer-like (DCL 2 and DCL3 encode Dicer activities important for small RNA-dependent gene silencing. Stress-induced HRF and DNA methylation were impaired in dcl2 and dcl3 deficiency mutants, while in dcl2 mutants, only stress-induced stress tolerance was impaired. Our results are consistent with the hypothesis that stress-induced transgenerational responses in Arabidopsis depend on altered DNA methylation and smRNA silencing pathways.

  7. The Arabidopsis downy mildew resistance gene, RPP13-Nd, functions independently of NDR1 and EDS1 and does not require the accumulation of salicylic acid.

    Science.gov (United States)

    Bittner-Eddy, P D; Beynon, J L

    2001-03-01

    RPP13-Nd-mediated resistance prevents parasitism by five isolates of Peronospora parasitica (At) in a transgenic Arabidopsis. Columbia background. We tested the effect of a number of known disease resistance mutations on the RPP13-Nd function and found that resistance remained unaltered in plants carrying mutations in either EDS1 or NDR1 and in double ndr1-1/eds1-2 mutant lines. Furthermore, we found that pbs2, pad4-1, npr1-1, and rps5-1, which compromise resistance to a number of P. parasitica (At) isolates, had no affect on RPP13-Nd function. In addition, RPP13-Nd-mediated resistance remained unchanged in a background of salicylic acid depletion (nahG). We conclude that RPP13-Nd is the first Arabidopsis R gene product reported to act via a novel signaling pathway that is independent of salicylic acid-mediated responses and is completely independent of NDR1 and EDS1.

  8. Carbonylation and Loss-of-Function Analyses of SBPase Reveal Its Metabolic Interface Role in Oxidative Stress, Carbon Assimilation, and Multiple Aspects of Growth and Development in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Xun-Liang Liu; Hai-Dong Yu; Yuan Guan; Ji-Kai Li; Fang-Qing Guo

    2012-01-01

    Sedoheptulose-1,7-bisphosphatase (SBPase) is a Calvin cycle enzyme and functions in photosynthetic carbon fixation.We found that SBPase was rapidly carbonylated in response to methyl viologen (MV) treatments in detached leaves of Arabidopsis plants.In vitro activity analysis of the purified recombinant SBPase showed that SBPase was carbonylated by hydroxyl radicals,which led to enzyme inactivation in an H2O2 dose-dependent manner.To determine the conformity with carbonylation-caused loss in enzymatic activity in response to stresses,we isolated a loss-of-function mutant sbp,which is deficient in SBPase-dependent carbon assimilation and starch biosynthesis,sbp mutant exhibited a severe growth retardation phenotype,especially for the developmental defects in leaves and flowers where SBPASE is highly expressed.The mutation of SBPASE caused growth retardation mainly through inhibition of cell division and expansion,which can be partially rescued by exogenous application of sucrose.Our findings demonstrate that ROS-induced oxidative damage to SBPase affects growth,development,and chloroplast biogenesis in Arabidopsis through inhibiting carbon assimilation efficiency.The data presented here provide a case study that such inactivation of SBPase caused by carbonyl modification may be a kind of adaptation for plants to restrict the operation of the reductive pentose phosphate pathway under stress conditions.

  9. Two Poplar Glycosyltransferase Genes, PdGATL1.1 and PdGATL1.2, Are Functional Orthologs to PARVUS/AtGATL 1 in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Yingzhen Kong; Gongke Zhou; Utku Avci; Xiaogang Gu; Chelsea Jones; Yanbin Yin; Ying Xu; Michael G. Hahn

    2009-01-01

    Several genes in Arabidopsis, including PARVUS/AtGATL1, have been implicated in xylan synthesis. However, the biosynthesis of xylan in woody plants, where this polysaccharide is a major component of wood, is poorly understood. Here, we characterize two Populus genes, PdGATL1.1 and PdGATL1.2, the closest orthologs to the Arabidopsis PARVUS/GATL 1 gene, with respect to their gene expression in poplar, their sub-cellular localization, and their ability to complement the parvus mutation in Arabidopsis. Overexpression of the two poplar genes in the parvus mutant rescued most of the defects caused by the parvus mutation, including morphological changes, collapsed xylem, and altered cell wall mono-saccharide composition. Quantitative RT-PCR showed that PdGATL1.1 is expressed most strongly in developing xylem of poplar. In contrast, PdGATL1.2 is expressed much more uniformly in leaf, shoot tip, cortex, phloem, and xylem, and the transcript level of PdGATL1.2 is much lower than that of PdGATL1.1 in all tissues examined. Sub-cellular localization experi-ments showed that these two proteins are localized to both ER and Golgi in comparison with marker proteins resident to these sub-cellular compartments. Our data indicate that PdGATLI.1 and PdGATL1.2 are functional orthologs of PARVUS/ GATL1 and can play a role in xylan synthesis, but may also have role(s) in the synthesis of other wall polymers.

  10. A Novel Function for Arabidopsis CYCLASE1 in Programmed Cell Death Revealed by Isobaric Tags for Relative and Absolute Quantitation (iTRAQ) Analysis of Extracellular Matrix Proteins.

    Science.gov (United States)

    Smith, Sarah J; Kroon, Johan T M; Simon, William J; Slabas, Antoni R; Chivasa, Stephen

    2015-06-01

    had no known function hitherto, is a negative regulator of cell death and regulates pathogen-induced symptom development in Arabidopsis.

  11. Subcellular localizations of Arabidopsis myotubularins MTM1 and MTM2 suggest possible functions in vesicular trafficking between ER and cis-Golgi.

    Science.gov (United States)

    Nagpal, Akanksha; Ndamukong, Ivan; Hassan, Ammar; Avramova, Zoya; Baluška, František

    2016-08-01

    The two Arabidopsis genes AtMTM1 and AtMTM2 encode highly similar phosphoinositide 3-phosphatases from the myotubularin family. Despite the high-level conservation of structure and biochemical activities, their physiological roles have significantly diverged. The nature of a membrane and the concentrations of their membrane-anchored substrates (PtdIns3P or PtdIns3,5P2) and/or products (PtdIns5P and PtdIns) are considered critical for determining the functional specificity of myotubularins. We have performed comprehensive analyses of the subcellular localization of AtMTM1 and AtMTM2 using a variety of specific constructs transiently expressed in Nicotiana benthamiana leaf epidermal cells under the control of 35S promoter. AtMTM1 co-localized preferentially with cis-Golgi membranes, while AtMTM2 associated predominantly with ER membranes. In a stark contrast with animal/human MTMs, neither AtMTM1 nor AtMTM2 co-localizes with early or late endosomes or with TGN/EE compartments, making them unlikely participants in the endosomal trafficking system. Localization of the AtMTM2 is sensitive to cold and osmotic stress challenges. In contrast to animal myotubularins, Arabidopsis myotubularins do not associate with endosomes. Our results suggest that Arabidopsis myotubularins play a role in the vesicular trafficking between ER exit sites and cis-Golgi elements. The significance of these results is discussed also in the context of stress biology and plant autophagy. PMID:27340857

  12. AtCDC5 regulates the G2 to M transition of the cell cycle and is critical for the function of Arabidopsis shoot apical meristem

    Institute of Scientific and Technical Information of China (English)

    Zhiqiang Lin; Kangquan Yin; Danling Zhu; Zhangliang Chen; Hongya Gu; LiJia Qu

    2007-01-01

    As a cell cycle regulator, the Myb-related CDC5 protein was reported to be essential for the G2 phase of the cell cycle in yeast and animals, but little is known about its function in plants. Here we report the functional characterization of the CDC5 gene in Arabidopsis thaliana. Arabidopsis CDC5 {AtCDCS) is mainly expressed in tissues with high cell division activity, and is expressed throughout the entire process of embryo formation. The AtCDCS loss-of-function mutant is embryonic lethal. In order to investigate the function of AtCDCS in vivo, we generated AtCDC5-RNAi plants in which the expression of AtCDCS was reduced by RNA interference. We found that the G2 to M (G2/M) phase transition was affected in the AtCDC5-RNAi plants, and that endoreduplication was increased. Additionally, the maintenance of shoot apical meristem (SAM) function was disturbed in the AtCDC5-KNAi plants, in which both the WUSCHEL (WUS)-CLAVATA (CLV) and the SHOOT MERISTEMLESS (STM) pathways were impaired. In situ hybridization analysis showed that the expression of STM was greatly reduced in the shoot apical cells of the AtCDC5-KNAi plants. Moreover, cyclinBl or Histone4 was found to be expressed in some of these cells when the transcript of STM was undetectable. These results suggest that AtCDC5 is essential for the G2/M phase transition and may regulate the function of SAM by controlling the expression of STM and WUS.

  13. AtbHLH29 of Arabidopsis thaliana is a functional ortholog of tomato FER involved in controlling iron acquisition in strategy I plants

    Institute of Scientific and Technical Information of China (English)

    You Xi YUAN; Juan ZHANG; Dao Wen WANG; Hong Qing LING

    2005-01-01

    AtbHLH29 of Arabidopsis, encoding a bHLH protein, reveals a high similarity to the tomato FER which is proposed as a transcriptional regulator involved in controlling the iron deficiency responses and the iron uptake in tomato. For identification of its biological functions, AtbHLH29 was introduced into the genome of the tomato FER mutant T3238fer mediated by Agrobacterium tumefaciencs. Transgenic plants were regenerated and the stable integration of AtbHLH29 into their genomes was confirmed by Southern hybridization. Molecular analysis demonstrated that expression of the exogenous AtbHLH29 of Arabidopsis in roots of the FER mutant T3238fer enabled to complement the defect functions of FER. The transgenic plants regained the ability to activate the whole iron deficiency responses and showed normal growth as the wild type under iron-limiting stress. Our transformation data demonstrate that AtbHLH29 is a functional ortholog of the tomato FER and can completely replace FER in controlling the effective iron acquisition in tomato.Except of iron, FER protein was directly or indirectly involved in manganese homeostasis due to that loss functions of FER in T3238fer resulted in strong reduction of Mn content in leaves and the defect function on Mn accumulation in leaves was complemented by expression of AtbHLH29 in the transgenic plants. Identification of the similar biological functions of FER and AtbHLH29, which isolated from two systematically wide-diverged "strategy I" plants, suggests that FER might be a universal gene presented in all strategy I plants in controlling effective iron acquisition system in roots.

  14. An in silico assessment of gene function and organization of the phenylpropanoid pathway metabolic networks in Arabidopsis thaliana and limitations thereof

    Science.gov (United States)

    Costa, Michael A.; Collins, R. Eric; Anterola, Aldwin M.; Cochrane, Fiona C.; Davin, Laurence B.; Lewis, Norman G.

    2003-01-01

    The Arabidopsis genome sequencing in 2000 gave to science the first blueprint of a vascular plant. Its successful completion also prompted the US National Science Foundation to launch the Arabidopsis 2010 initiative, the goal of which is to identify the function of each gene by 2010. In this study, an exhaustive analysis of The Institute for Genomic Research (TIGR) and The Arabidopsis Information Resource (TAIR) databases, together with all currently compiled EST sequence data, was carried out in order to determine to what extent the various metabolic networks from phenylalanine ammonia lyase (PAL) to the monolignols were organized and/or could be predicted. In these databases, there are some 65 genes which have been annotated as encoding putative enzymatic steps in monolignol biosynthesis, although many of them have only very low homology to monolignol pathway genes of known function in other plant systems. Our detailed analysis revealed that presently only 13 genes (two PALs, a cinnamate-4-hydroxylase, a p-coumarate-3-hydroxylase, a ferulate-5-hydroxylase, three 4-coumarate-CoA ligases, a cinnamic acid O-methyl transferase, two cinnamoyl-CoA reductases) and two cinnamyl alcohol dehydrogenases can be classified as having a bona fide (definitive) function; the remaining 52 genes currently have undetermined physiological roles. The EST database entries for this particular set of genes also provided little new insight into how the monolignol pathway was organized in the different tissues and organs, this being perhaps a consequence of both limitations in how tissue samples were collected and in the incomplete nature of the EST collections. This analysis thus underscores the fact that even with genomic sequencing, presumed to provide the entire suite of putative genes in the monolignol-forming pathway, a very large effort needs to be conducted to establish actual catalytic roles (including enzyme versatility), as well as the physiological function(s) for each member

  15. Structure-function relationship of a plant NCS1 member - Homology modeling and mutagenesis identified residues critical for substrate specificity of PLUTO, a nucleobase transporter from arabidopsis

    KAUST Repository

    Witz, Sandra

    2014-03-12

    Plastidic uracil salvage is essential for plant growth and development. So far, PLUTO, the plastidic nucleobase transporter from Arabidopsis thaliana is the only known uracil importer at the inner plastidic membrane which represents the permeability barrier of this organelle. We present the first homology model of PLUTO, the sole plant NCS1 member from Arabidopsis based on the crystal structure of the benzyl hydantoin transporter MHP1 from Microbacterium liquefaciens and validated by molecular dynamics simulations. Polar side chains of residues Glu-227 and backbones of Val-145, Gly-147 and Thr-425 are proposed to form the binding site for the three PLUTO substrates uracil, adenine and guanine. Mutational analysis and competition studies identified Glu-227 as an important residue for uracil and to a lesser extent for guanine transport. A differential response in substrate transport was apparent with PLUTO double mutants E227Q G147Q and E227Q T425A, both of which most strongly affected adenine transport, and in V145A G147Q, which markedly affected guanine transport. These differences could be explained by docking studies, showing that uracil and guanine exhibit a similar binding mode whereas adenine binds deep into the catalytic pocket of PLUTO. Furthermore, competition studies confirmed these results. The present study defines the molecular determinants for PLUTO substrate binding and demonstrates key differences in structure-function relations between PLUTO and other NCS1 family members. 2014 Witz et al.

  16. Structure-function relationship of a plant NCS1 member--homology modeling and mutagenesis identified residues critical for substrate specificity of PLUTO, a nucleobase transporter from Arabidopsis.

    Science.gov (United States)

    Witz, Sandra; Panwar, Pankaj; Schober, Markus; Deppe, Johannes; Pasha, Farhan Ahmad; Lemieux, M Joanne; Möhlmann, Torsten

    2014-01-01

    Plastidic uracil salvage is essential for plant growth and development. So far, PLUTO, the plastidic nucleobase transporter from Arabidopsis thaliana is the only known uracil importer at the inner plastidic membrane which represents the permeability barrier of this organelle. We present the first homology model of PLUTO, the sole plant NCS1 member from Arabidopsis based on the crystal structure of the benzyl hydantoin transporter MHP1 from Microbacterium liquefaciens and validated by molecular dynamics simulations. Polar side chains of residues Glu-227 and backbones of Val-145, Gly-147 and Thr-425 are proposed to form the binding site for the three PLUTO substrates uracil, adenine and guanine. Mutational analysis and competition studies identified Glu-227 as an important residue for uracil and to a lesser extent for guanine transport. A differential response in substrate transport was apparent with PLUTO double mutants E227Q G147Q and E227Q T425A, both of which most strongly affected adenine transport, and in V145A G147Q, which markedly affected guanine transport. These differences could be explained by docking studies, showing that uracil and guanine exhibit a similar binding mode whereas adenine binds deep into the catalytic pocket of PLUTO. Furthermore, competition studies confirmed these results. The present study defines the molecular determinants for PLUTO substrate binding and demonstrates key differences in structure-function relations between PLUTO and other NCS1 family members. PMID:24621654

  17. Cold-inducible expression of AZI1 and its function in improvement of freezing tolerance of Arabidopsis thaliana and Saccharomyces cerevisiae.

    Science.gov (United States)

    Xu, Zhi-Yan; Zhang, Xin; Schläppi, Michael; Xu, Zi-Qin

    2011-09-01

    AZI1 (AZELAIC ACID INDUCED 1) of Arabidopsis thaliana could be induced by azelaic acid and was involved in priming of systemic plant immunity. In the present work, expression of AZI1 in response to low temperature was investigated via RNA gel blot analysis. AZI1 could be induced slowly by cold stress and more than 6h treatment at 4°C was required to detect an increase in mRNA abundance. However, the high expression state could not be maintained stably and would decline to basal level when the plants were transferred to room temperature. In order to clarify the function of AZI1 in resistance to abiotic stresses, overexpressing, RNA interference and T-DNA knockout lines of this gene were used in electrolyte leakage assays. Overexpression of AZI1 resulted in reduced electrolyte leakage during freezing damage. In contrast, AZI1 knockdown and knockout lines showed increased tendencies in cellular damage after freezing treatment. To further validate the potential resistance of AZI1 to low-temperature stress, Saccharomyces cerevisiae cells were transformed with pESC-AZI1 in which AZI1 was under the control of GAL1 promoter. Compared to yeast cells containing empty pESC-URA, the survival rate of yeast cells harboring AZI1 increased obviously after freezing treatment. All these results suggested that AZI1 might be multifunctional and associated with cold tolerance of Arabidopsis.

  18. Structure-function relationship of a plant NCS1 member--homology modeling and mutagenesis identified residues critical for substrate specificity of PLUTO, a nucleobase transporter from Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Sandra Witz

    Full Text Available Plastidic uracil salvage is essential for plant growth and development. So far, PLUTO, the plastidic nucleobase transporter from Arabidopsis thaliana is the only known uracil importer at the inner plastidic membrane which represents the permeability barrier of this organelle. We present the first homology model of PLUTO, the sole plant NCS1 member from Arabidopsis based on the crystal structure of the benzyl hydantoin transporter MHP1 from Microbacterium liquefaciens and validated by molecular dynamics simulations. Polar side chains of residues Glu-227 and backbones of Val-145, Gly-147 and Thr-425 are proposed to form the binding site for the three PLUTO substrates uracil, adenine and guanine. Mutational analysis and competition studies identified Glu-227 as an important residue for uracil and to a lesser extent for guanine transport. A differential response in substrate transport was apparent with PLUTO double mutants E227Q G147Q and E227Q T425A, both of which most strongly affected adenine transport, and in V145A G147Q, which markedly affected guanine transport. These differences could be explained by docking studies, showing that uracil and guanine exhibit a similar binding mode whereas adenine binds deep into the catalytic pocket of PLUTO. Furthermore, competition studies confirmed these results. The present study defines the molecular determinants for PLUTO substrate binding and demonstrates key differences in structure-function relations between PLUTO and other NCS1 family members.

  19. Frataxin Is Localized to Both the Chloroplast and Mitochondrion and Is Involved in Chloroplast Fe-S Protein Function in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Valeria R Turowski

    Full Text Available Frataxin plays a key role in eukaryotic cellular iron metabolism, particularly in mitochondrial heme and iron-sulfur (Fe-S cluster biosynthesis. However, its precise role has yet to be elucidated. In this work, we studied the subcellular localization of Arabidopsis frataxin, AtFH, using confocal microscopy, and found a novel dual localization for this protein. We demonstrate that plant frataxin is targeted to both the mitochondria and the chloroplast, where it may play a role in Fe-S cluster metabolism as suggested by functional studies on nitrite reductase (NIR and ferredoxin (Fd, two Fe-S containing chloroplast proteins, in AtFH deficient plants. Our results indicate that frataxin deficiency alters the normal functioning of chloroplasts by affecting the levels of Fe, chlorophyll, and the photosynthetic electron transport chain in this organelle.

  20. Identification of a functionally essential amino acid for Arabidopsis cyclic nucleotide gated ion channels using the chimeric AtCNGC11/12 gene.

    Science.gov (United States)

    Baxter, Joyce; Moeder, Wolfgang; Urquhart, William; Shahinas, Dea; Chin, Kimberley; Christendat, Dinesh; Kang, Hong-Gu; Angelova, Magdalena; Kato, Naohiro; Yoshioka, Keiko

    2008-11-01

    We used the chimeric Arabidopsis cyclic nucleotide-gated ion channel AtCNGC11/12 to conduct a structure-function study of plant cyclic nucleotide-gated ion channels (CNGCs). AtCNGC11/12 induces multiple pathogen resistance responses in the Arabidopsis mutant constitutive expresser of PR genes 22 (cpr22). A genetic screen for mutants that suppress cpr22-conferred phenotypes identified an intragenic mutant, #73, which has a glutamate to lysine substitution (E519K) at the beginning of the eighth beta-sheet of the cyclic nucleotide-binding domain in AtCNGC11/12. The #73 mutant is morphologically identical to wild-type plants and has lost cpr22-related phenotypes including spontaneous cell death and enhanced pathogen resistance. Heterologous expression analysis using a K(+)-uptake-deficient yeast mutant revealed that this Glu519 is important for AtCNGC11/12 channel function, proving that the occurrence of cpr22 phenotypes requires active channel function of AtCNGC11/12. Additionally, Glu519 was also found to be important for the function of the wild-type channel AtCNGC12. Computational structural modeling and in vitro cAMP-binding assays suggest that Glu519 is a key residue for the structural stability of AtCNGCs and contributes to the interaction of the cyclic nucleotide-binding domain and the C-linker domain, rather than the binding of cAMP. Furthermore, a mutation in the alpha-subunit of the human cone receptor CNGA3 that causes total color blindness aligned well to the position of Glu519 in AtCNGC11/12. This suggests that AtCNGC11/12 suppressors could be a useful tool for discovering important residues not only for plant CNGCs but also for CNGCs in general. PMID:18643993

  1. Arabidopsis RRP6L1 and RRP6L2 function in FLOWERING LOCUS C silencing via regulation of antisense RNA synthesis.

    Directory of Open Access Journals (Sweden)

    Jun-Hye Shin

    2014-09-01

    Full Text Available The exosome complex functions in RNA metabolism and transcriptional gene silencing. Here, we report that mutations of two Arabidopsis genes encoding nuclear exosome components AtRRP6L1 and AtRRP6L2, cause de-repression of the main flowering repressor FLOWERING LOCUS C (FLC and thus delay flowering in early-flowering Arabidopsis ecotypes. AtRRP6L mutations affect the expression of known FLC regulatory antisense (AS RNAs AS I and II, and cause an increase in Histone3 K4 trimethylation (H3K4me3 at FLC. AtRRP6L1 and AtRRP6L2 function redundantly in regulation of FLC and also act independently of the exosome core complex. Moreover, we discovered a novel, long non-coding, non-polyadenylated antisense transcript (ASL, for Antisense Long originating from the FLC locus in wild type plants. The AtRRP6L proteins function as the main regulators of ASL synthesis, as these mutants show little or no ASL transcript. Unlike ASI/II, ASL associates with H3K27me3 regions of FLC, suggesting that it could function in the maintenance of H3K27 trimethylation during vegetative growth. AtRRP6L mutations also affect H3K27me3 levels and nucleosome density at the FLC locus. Furthermore, AtRRP6L1 physically associates with the ASL transcript and directly interacts with the FLC locus. We propose that AtRRP6L proteins participate in the maintenance of H3K27me3 at FLC via regulating ASL. Furthermore, AtRRP6Ls might participate in multiple FLC silencing pathways by regulating diverse antisense RNAs derived from the FLC locus.

  2. The Arabidopsis P4-ATPase ALA3 requires a ß-subunit to function in phospholipid translocation and secretory vesicle formation

    DEFF Research Database (Denmark)

    Lopez Marques, Rosa Laura

    . The root growth defect is accompanied by the failure of the root to release border cells of the root cap. Electron micrograph data suggest that functioning and shedding of border cells are dependent on ALA3, as ala3 mutants are devoid of the characteristic proliferation of slime vesicles at the trans....... Palmgren1 1Centre for Membrane Pumps in Cells and Disease - PUMPKIN, Danish National Research Foundation, Department of Plant Biology, University of Copenhagen, DK-1871 Frederiksberg C, Denmark 2Biochemistry Department MS200, University of Nevada Reno, NV 89557, USA 3Humboldt-University Berlin, Faculty...... and in inducing membrane curvature, which is a requirement for vesicle formation. We show that Aminophospholipid ATPase3 (ALA3), a member of the P4-ATPase subfamily in the plant Arabidopsis thaliana, localizes to the Golgi apparatus and that genetic lesions of ALA3 result in impaired growth of roots and shoots...

  3. A functional EDS1 ortholog is differentially regulated in powdery mildew resistant and susceptible grapevines and complements an Arabidopsis eds1 mutant.

    Science.gov (United States)

    Gao, Fei; Shu, Xiaomei; Ali, Mohammad Babar; Howard, Susanne; Li, Nan; Winterhagen, Patrick; Qiu, Wenping; Gassmann, Walter

    2010-04-01

    Vitis vinifera (grapevine) is the most economically important deciduous fruit crop, but cultivated grapevine varieties lack adequate innate immunity to a range of devastating diseases. To identify genetic resources for grapevine innate immunity and understand pathogen defense pathways in a woody perennial plant, we focus in this study on orthologs of the central Arabidopsis thaliana defense regulator ENHANCED DISEASE SUSCEPTIBILITY1 (EDS1). The family of EDS1-like genes is expanded in grapevine, and members of this family were previously found to be constitutively upregulated in the resistant variety 'Norton' of the North American grapevine species Vitis aestivalis, while they were induced by Erysiphe necator, the causal agent of grapevine powdery mildew (PM), in the susceptible V. vinifera variety 'Cabernet Sauvignon'. Here, we determine the responsiveness of individual EDS1-like genes in grapevine to PM and salicylic acid, and find that EDS1-like paralogs are differentially regulated in 'Cabernet Sauvignon', while two are constitutively upregulated in 'Norton'. Sequencing of VvEDS1 and VaEDS1 cDNA and genomic clones revealed high conservation in the protein-encoding sequence and some divergence of the promoter sequence in the two grapevine varieties. Complementation of the Arabidopsis eds1-1 mutant showed that the EDS1-like gene with highest predicted amino acid sequence similarity to AtEDS1 from either grapevine varieties is a functional ortholog of AtEDS1. Together, our analyses show that differential susceptibility to PM is correlated with differences in EDS1 expression, not differences in EDS1 function, between resistant 'Norton' and susceptible 'Cabernet Sauvignon'.

  4. The Arabidopsis thalianaK+-uptake permease 7 (AtKUP7) contains a functional cytosolic adenylate cyclase catalytic centre

    KAUST Repository

    Al-Younis, Inas

    2015-11-27

    Adenylate Cyclases (ACs) catalyze the formation of the second messenger cyclic adenosine 3′, 5′-monophosphate (cAMP) from adenosine 5’-triphosphate (ATP). Although cAMP is increasingly recognized as an important signaling molecule in higher plants, ACs have remained somewhat elusive. Here we used a search motif derived from experimentally tested guanylyl cyclases (GCs), substituted the residues essential for substrate specificity and identified the Arabidopsis thaliana K+-uptake permease 7 (AtKUP7) as one of several candidate ACs. Firstly, we show that a recombinant N-terminal, cytosolic domain of AtKUP71-100 is able to complement the AC-deficient mutant cyaA in Escherichia coli and thus restoring the fermentation of lactose, and secondly, we demonstrate with both enzyme immunoassays and mass spectrometry that a recombinant AtKUP71-100 generates cAMP in vitro.

  5. The Arabidopsis thaliana K(+)-uptake permease 7 (AtKUP7) contains a functional cytosolic adenylate cyclase catalytic centre.

    Science.gov (United States)

    Al-Younis, Inas; Wong, Aloysius; Gehring, Chris

    2015-12-21

    Adenylate cyclases (ACs) catalyse the formation of the second messenger cyclic adenosine 3',5'-monophosphate (cAMP) from adenosine 5'-triphosphate (ATP). Although cAMP is increasingly recognised as an important signalling molecule in higher plants, ACs have remained somewhat elusive. Here we used a search motif derived from experimentally tested guanylyl cyclases (GCs), substituted the residues essential for substrate specificity and identified the Arabidopsis thaliana K(+)-uptake permease 7 (AtKUP7) as one of several candidate ACs. Firstly, we show that a recombinant N-terminal, cytosolic domain of AtKUP7(1-100) is able to complement the AC-deficient mutant cyaA in Escherichia coli and thus restoring the fermentation of lactose, and secondly, we demonstrate with both enzyme immunoassays and mass spectrometry that a recombinant AtKUP7(1-100) generates cAMP in vitro. PMID:26638082

  6. Function of type-2 Arabidopsis hemoglobin in the auxin-mediated formation of embryogenic cells during morphogenesis

    DEFF Research Database (Denmark)

    Elhiti, Mohamed; Hebelstrup, Kim; Wang, Aiming;

    2013-01-01

    Suppression of the Arabidopsis GLB2, a type-2 nonsymbiotic hemoglobin, enhances somatic embryogenesis by increasing auxin production. In the glb2 knock-out line (GLB2 -/-) polarization of PIN1 proteins and auxin maxima occurred at the base of the cotyledons of the zygotic explants, which...... are the sites of embryogenic tissue formation. These changes were also accompanied by a transcriptional up-regulation of WUSCHEL (WUS) and SOMATIC EMBRYOGENESIS RECEPTOR KINASE (SERK1), markers of embryogenic competence. The increased auxin levels in the GLB2 -/- line were ascribed to the induction of several...... the embryogenic cells, which repress the expression of the transcription factor MYC2, a well characterized repressor of the auxin biosynthetic pathway. A model is proposed in which the suppression of GLB2 reduces the degree of NO scavenging by oxyhemoglobin, thereby increasing the cellular NO concentration...

  7. PMRP Expression Characteristics and Analysisof the Function inArabidopsis%拟南芥PMRP的表达特性及功能分析

    Institute of Scientific and Technical Information of China (English)

    张昊; 由诗东; 高静; 张海丽; 李生辉; 邢继红; 王凤茹; 董金皋

    2014-01-01

    [Objective]The objective of this study is to analyze the expression characteristics ofPMRP (putative membrane related protein)gene (the biological funcion was unknown )inArabidopsis, and make clear of the regulation function of PMRP in Arabidopsis development process.[Method]Bioinformatics method was used to look for the genes which contain the same domain with PMRP in Arabidopsisand draw the phylogenetic tree. Real-time PCR technique was used to analyze the expression level of PMRP in root and stem tissues of 8 and 21 daysArabidopsis,compare the expression ofPMRP gene in the 1st, 2nd, 3rd and the 4th pairs of rosette leaves and cauline leaves in 21 daysArabidopsis, analyze the expression level ofPMRPin flower organs (such as sepals, stamens and petals) and seeds ofArabidopsis. The gain-of-function mutant of PMRP were obtained by constructing a vector ofPMRP gene driven by the 35S promoter of the cauliflower mosaic virus, and introduced it into wild typeArabidopsis Columbia, then tested the expression level of PMRP by RT-PCR technique. The regulating effect ofPMRP gene on the growth sites of leaves and stems was analyzed by observing the phenotype of the35S:PMRP transgenic plants. The function ofPMRP gene in differentiation of vascular xylem and phloem was observed using the paraffin sections of the stem transverse section in thePMRP over-expressing transgenicArabidopsis. The effect ofPMRP on the growth and developmentof Arabidopsis floral organ was studied through observation of the floral organ anatomy. The effect ofPMRP on fertility inArabidopsis thaliana was analyzed by observing the pod formation in thePMRP over-expressing transgenicArabidopsis.[Result]PMRP is a 411 amino acids protein which containing a START domain and have transmenbrane segments, there are 35 START proteins inArabidopsis. Real-time PCR analysis results showed that the expression level ofPMRP was higher in cauline leaves ( the relative expression ofPMRPwas about 2 935) and then the rosette

  8. The Arabidopsis KH-Domain RNA-Binding Protein ESR1 Functions in Components of Jasmonate Signalling, Unlinking Growth Restraint and Resistance to Stress.

    Directory of Open Access Journals (Sweden)

    Louise F Thatcher

    Full Text Available Glutathione S-transferases (GSTs play important roles in the protection of cells against toxins and oxidative damage where one Arabidopsis member, GSTF8, has become a commonly used marker gene for early stress and defense responses. A GSTF8 promoter fragment fused to the luciferase reporter gene was used in a forward genetic screen for Arabidopsis mutants with up-regulated GSTF8 promoter activity. This identified the esr1-1 (enhanced stress response 1 mutant which also conferred increased resistance to the fungal pathogen Fusarium oxysporum. Through positional cloning, the ESR1 gene was found to encode a KH-domain containing RNA-binding protein (At5g53060. Whole transcriptome sequencing of esr1-1 identified altered expression of genes involved in responses to biotic and abiotic stimuli, hormone signaling pathways and developmental processes. In particular was an overall significant enrichment for jasmonic acid (JA mediated processes in the esr1-1 down-regulated dataset. A subset of these genes were tested for MeJA inducibility and we found the expression of some but not all were reduced in esr1-1. The esr1-1 mutant was not impaired in other aspects of JA-signalling such as JA- sensitivity or development, suggesting ESR1 functions in specific components of the JA-signaling pathway. Examination of salicylic acid (SA regulated marker genes in esr1-1 showed no increase in basal or SA induced expression suggesting repression of JA-regulated genes is not due to antagonistic SA-JA crosstalk. These results define new roles for KH-domain containing proteins with ESR1 unlinking JA-mediated growth and defense responses.

  9. A Dual-Function Transcription Factor, AtYY1, Is a Novel Negative Regulator of the Arabidopsis ABA Response Network.

    Science.gov (United States)

    Li, Tian; Wu, Xiu-Yun; Li, Hui; Song, Jian-Hui; Liu, Jin-Yuan

    2016-05-01

    Abscisic acid (ABA) plays crucial roles in plant growth and development, as well as in response to various environmental stresses. To date, many regulatory genes involved in the ABA response network have been identified; however, their roles have remained to be fully elucidated. In this study, we identified AtYY1, an Arabidopsis homolog of the mammalian C2H2 zinc-finger transcription factor Yin Yang 1 (YY1), as a novel negative regulator of the ABA response. AtYY1 is a dual-function transcription factor with both repression and activation domains. The expression of AtYY1 was induced by ABA and stress conditions including high salt and dehydration. The yy1 mutant was more sensitive to ABA and NaCl than the wild-type, while overexpressing AtYY1 plants were less sensitive. AtYY1 loss also enhanced ABA-induced stomatal closing and drought resistance. Moreover, AtYY1 can bind the ABA REPRESSOR1 (ABR1) promoter and directly upregulate ABR1 expression, as well as negatively regulate ABA- and salt-responsive gene expression. Additional analysis indicated that ABA INSENSITIVE4 (ABI4) might positively regulate AtYY1 expression and that ABR1 can antagonize this regulation. Our findings provide direct evidence that AtYY1 is a novel negative regulator of the ABA response network and that the ABI4-AtYY1-ABR1 regulatory pathway may fine-tune ABA-responsive gene expression in Arabidopsis. PMID:26961720

  10. An SGS3-like protein functions in RNA-directed DNA methylation and transcriptional gene silencing in Arabidopsis

    KAUST Repository

    Zheng, Zhimin

    2010-01-06

    RNA-directed DNA methylation (RdDM) is an important epigenetic mechanism for silencing transgenes and endogenous repetitive sequences such as transposons. The RD29A promoter-driven LUCIFERASE transgene and its corresponding endogenous RD29A gene are hypermethylated and silenced in the Arabidopsis DNA demethylase mutant ros1. By screening for second-site suppressors of ros1, we identified the RDM12 locus. The rdm12 mutation releases the silencing of the RD29A-LUC transgene and the endogenous RD29A gene by reducing the promoter DNA methylation. The rdm12 mutation also reduces DNA methylation at endogenous RdDM target loci, including transposons and other repetitive sequences. In addition, the rdm12 mutation affects the levels of small interfering RNAs (siRNAs) from some of the RdDM target loci. RDM12 encodes a protein with XS and coiled-coil domains, and is similar to SGS3, which is a partner protein of RDR6 and can bind to double-stranded RNAs with a 5′ overhang, and is required for several post-transcriptional gene silencing pathways. Our results show that RDM12 is a component of the RdDM pathway, and suggest that RdDM may involve double-stranded RNAs with a 5′ overhang and the partnering between RDM12 and RDR2. © 2010 Blackwell Publishing Ltd.

  11. Pattern of CsICE1 expression under cold or drought treatment and functional verification through analysis of transgenic Arabidopsis.

    Science.gov (United States)

    Ding, Z T; Li, C; Shi, H; Wang, H; Wang, Y

    2015-01-01

    CsICE1 is thought to be involved in hardiness resistance of tea plants. Using seedling cuttings of biennial Wuniuzao in this study, the pattern of CsICE1 expression under cold temperature (4°, -5°C), drought [20% polyethylene glycol 6000 (PEG-6000)], and plant hormone [200 mg/L abscisic acid (ABA), 1 mg/L brassinolide (BR)] treatment was studied by real-time quantitative PCR. Additionally, stress resistance, such as the freezing resistance of CsICE1, was studied using Arabidopsis lines transformed with sense or anti-sense CsICE1 via Agrobacterium tumefaciens infection. Our results showed that CsICE1 mRNA could be induced under -5°C, PEG, ABA, or BR treatment, although the pattern of expression differed for all treatments. Compared to wild type (WT) and anti-sense ICE1 transgenic lines, sense lines displayed higher relative germination rates under salt and drought stress. After freezing treatment, the sense transgenic lines over-expressing CsICE1 showed a higher survival rate, increased levels of proline, and decreased levels of malonaldehyde. Conversely, compared with WT, anti-sense ICE1 transgenic lines had lower proline levels and higher malonaldehyde levels under freezing conditions. Our study indicates that CsICE1 is an important anti-freezing gene and that over-expression of CsICE1 can improve cold resistance and enhance salt and drought tolerance of transgenic lines. PMID:26400357

  12. A mitochondrial alkaline/neutral invertase isoform (A/N-InvC) functions in developmental energy-demanding processes in Arabidopsis.

    Science.gov (United States)

    Martín, Mariana L; Lechner, Leandra; Zabaleta, Eduardo J; Salerno, Graciela L

    2013-03-01

    Recent findings demonstrate that alkaline/neutral invertases (A/N-Invs), enzymes that catalyze the breakdown of sucrose into glucose and fructose, are essential proteins in plant life. The fact that different isoforms are present in multiple locations makes them candidates for the coordination of metabolic processes. In the present study, we functionally characterized the encoding gene of a novel A/N-Inv (named A/N-InvC) from Arabidopsis, which localizes in mitochondria. A/N-InvC is expressed in roots, in aerial parts (shoots and leaves) and flowers. A detailed phenotypic analysis of knockout mutant plants (invc) reveals an impaired growth phenotype. Shoot growth was severely reduced, but root development was not affected as reported for A/N-InvA mutant (inva) plants. Remarkably, germination and flowering, two energy demanding processes, were the most affected stages. The effect of exogenous growth regulators led us to suggest that A/N-InvC may be modulating hormone balance in relation to the radicle emergence. We also show that oxygen consumption is reduced in inva and invc in comparison with wild-type plants, indicating that both organelle isoenzymes may play a fundamental role in mitochondrion functionality. Taken together, our results emphasize the involvement of mitochondrial A/N-Invs in developmental processes and uncover the possibility of playing different roles for the two isoforms located in the organelle.

  13. Contribution of PPi-Hydrolyzing Function of Vacuolar H(+)-Pyrophosphatase in Vegetative Growth of Arabidopsis: Evidenced by Expression of Uncoupling Mutated Enzymes.

    Science.gov (United States)

    Asaoka, Mariko Mariko Asaoka; Segami, Shoji; Ferjani, Ali; Maeshima, Masayoshi

    2016-01-01

    The vacuolar-type H(+)-pyrophosphatase (H(+)-PPase) catalyzes a coupled reaction of pyrophosphate (PPi) hydrolysis and active proton translocation across the tonoplast. Overexpression of H(+)-PPase improves growth in various plant species, and loss-of-function mutants (fugu5s) of H(+)-PPase in Arabidopsis thaliana have post-germinative developmental defects. Here, to further clarify the physiological significance of this important enzyme, we newly generated three varieties of H(+)-PPase overexpressing lines with different levels of activity that we analyzed together with the loss-of-function mutant fugu5-3. The H(+)-PPase overexpressors exhibited enhanced activity of H(+)-PPase during vegetative growth, but no change in the activity of vacuolar H(+)-ATPase. Overexpressors with high enzymatic activity grew more vigorously with fresh weight increased by more than 24 and 44%, compared to the wild type and fugu5-3, respectively. Consistently, the overexpressors had larger rosette leaves and nearly 30% more cells in leaves than the wild type. When uncoupling mutated variants of H(+)-PPase, that could hydrolyze PPi but could not translocate protons, were introduced into the fugu5-3 mutant background, shoot growth defects recovered to the same levels as when a normal H(+)-PPase was introduced. Taken together, our findings clearly demonstrate that additional expression of H(+)-PPase improves plant growth by increasing cell number, predominantly as a consequence of the PPi-hydrolyzing activity of the enzyme.

  14. The cbfs triple mutants reveal the essential functions of CBFs in cold acclimation and allow the definition of CBF regulons in Arabidopsis.

    Science.gov (United States)

    Jia, Yuxin; Ding, Yanglin; Shi, Yiting; Zhang, Xiaoyan; Gong, Zhizhong; Yang, Shuhua

    2016-10-01

    In Arabidopsis, the C-repeat binding factors (CBFs) have been extensively studied as key transcription factors in the cold stress response. However, their exact functions in the cold response remains unclear due to the lack of a null cbf triple mutant. In this study, we used CRISPR/Cas9 technology to mutate CBF1 or CBF1/CBF2 in a cbf3 T-DNA insertion mutant to generate cbf1,3 double and cbf1 cbf2 cbf3 (cbfs) triple mutants. The response of the cbfs triple mutants to chilling stress is impaired. Furthermore, no significant difference in freezing tolerance was observed between the wild-type and the cbf1,3 and cbfs mutants without cold acclimation. However, the cbfs mutants were extremely sensitive to freezing stress after cold acclimation, and freezing sensitivity ranking was cbfs > cbf1,3 > cbf3. RNA-Seq analysis showed that 134 genes were CBF regulated, of which 112 were regulated positively and 22 negatively by CBFs. Our study reveals the essential functions of CBFs in chilling stress response and cold acclimation, as well as defines a set of genes as CBF regulon. It also provides materials for the genetic dissection of components in CBF-dependent cold signaling. PMID:27353960

  15. Downy mildew (Peronospora parasitica) resistance genes in Arabidopsis vary in functional requirements for NDR1, EDS1, NPR1 and salicylic acid accumulation.

    Science.gov (United States)

    McDowell, J M; Cuzick, A; Can, C; Beynon, J; Dangl, J L; Holub, E B

    2000-06-01

    To better understand the genetic requirements for R gene-dependent defense activation in Arabidopsis, we tested the effect of several defense response mutants on resistance specified by eight RPP genes (for resistance to Peronospora parasitica) expressed in the Col-0 background. In most cases, resistance was not suppressed by a mutation in the SAR regulatory gene NPR1 or by expression of the NahG transgene. Thus, salicylic acid accumulation and NPR1 function are not necessary for resistance mediated by these RPP genes. In addition, resistance conferred by two of these genes, RPP7 and RPP8, was not significantly suppressed by mutations in either EDS1 or NDR1. RPP7 resistance was also not compromised by mutations in EIN2, JAR1 or COI1 which affect ethylene or jasmonic acid signaling. Double mutants were therefore tested. RPP7 and RPP8 were weakly suppressed in an eds1-2/ndr1-1 background, suggesting that these RPP genes operate additively through EDS1, NDR1 and as-yet-undefined signaling components. RPP7 was not compromised in coi1/npr1 or coi1/NahG backgrounds. These observations suggest that RPP7 initiates resistance through a novel signaling pathway that functions independently of salicylic acid accumulation or jasmonic acid response components.

  16. Characterization of the promoter and extended C-terminal domain of Arabidopsis WRKY33 and functional analysis of tomato WRKY33 homologues in plant stress responses.

    Science.gov (United States)

    Zhou, Jie; Wang, Jian; Zheng, Zuyu; Fan, Baofang; Yu, Jing-Quan; Chen, Zhixiang

    2015-08-01

    Arabidopsis AtWRKY33 plays a critical role in broad plant stress responses. Whether there are evolutionarily conserved homologues of AtWRKY33 in other plants and what make AtWRKY33 such an important protein in plant stress responses are largely unknown. We compared AtWRKY33 with its close homologues to identify AtWRKY33-specific regulatory and structural elements, which were then functionally analysed through complementation. We also performed phylogenetic analysis to identify structural AtWRKY33 homologues in other plants and functionally analysed two tomato homologues through complementation and gene silencing. AtWRKY33 has an extended C-terminal domain (CTD) absent in its close homologue AtWRKY25. Both its CTD and the strong pathogen/stress-responsive expression of AtWRKY33 are necessary to complement the critical phenotypes of atwrky33. Structural AtWRKY33 homologues were identified in both dicot and monocot plants including two (SlWRKY33A and SlWRKY33B) in tomato. Molecular complementation and gene silencing confirmed that the two tomato WRKY genes play a critical role similar to that of AtWRKY33 in plant stress responses. Thus, WRKY33 proteins are evolutionarily conserved with a critical role in broad plant stress responses. Both its CTD and promoter are critical for the uniquely important roles of WRKY33 in plant stress responses.

  17. The BEACH Domain Protein SPIRRIG Is Essential for Arabidopsis Salt Stress Tolerance and Functions as a Regulator of Transcript Stabilization and Localization.

    Directory of Open Access Journals (Sweden)

    Alexandra Steffens

    2015-07-01

    Full Text Available Members of the highly conserved class of BEACH domain containing proteins (BDCPs have been established as broad facilitators of protein-protein interactions and membrane dynamics in the context of human diseases like albinism, bleeding diathesis, impaired cellular immunity, cancer predisposition, and neurological dysfunctions. Also, the Arabidopsis thaliana BDCP SPIRRIG (SPI is important for membrane integrity, as spi mutants exhibit split vacuoles. In this work, we report a novel molecular function of the BDCP SPI in ribonucleoprotein particle formation. We show that SPI interacts with the P-body core component DECAPPING PROTEIN 1 (DCP1, associates to mRNA processing bodies (P-bodies, and regulates their assembly upon salt stress. The finding that spi mutants exhibit salt hypersensitivity suggests that the local function of SPI at P-bodies is of biological relevance. Transcriptome-wide analysis revealed qualitative differences in the salt stress-regulated transcriptional response of Col-0 and spi. We show that SPI regulates the salt stress-dependent post-transcriptional stabilization, cytoplasmic agglomeration, and localization to P-bodies of a subset of salt stress-regulated mRNAs. Finally, we show that the PH-BEACH domains of SPI and its human homolog FAN (Factor Associated with Neutral sphingomyelinase activation interact with DCP1 isoforms from plants, mammals, and yeast, suggesting the evolutionary conservation of an association of BDCPs and P-bodies.

  18. Allelic Analyses of the Arabidopsis YUC1 Locus Reveal Residues and Domains Essential for the Functions of YUC Family of Flavin Monooxygenases

    Institute of Scientific and Technical Information of China (English)

    Xianhui Hou; Sainan Liu; Florencia Pierri; Xinhua Dai; Li-Jia Qu; Yunde Zhao

    2011-01-01

    Flavin monooxygenases(FMOs)play critical roles in plant growth and development by synthesizing auxin and other signaling molecules.However,the structure and function relationship within plant FMOs is not understood.Here we defined the important residues and domains of the Arabidopsis YUC1 FMO,a key enzyme in auxin biosynthesis.We previously showed that simultaneous inactivation of YUC1 and its homologue YUC4 caused severe defects in vascular and floral development.We mutagenized the yuc4 mutant and screened for mutants with phenotypes similar to those of yuc1 yuc4 double mutants.Among the isolated mutants,five of them contained mutations in the YUC1 gene.Interestingly,the mutations identified in the new yuc1 alleles were concentrated in the two GXGXXG motifs that are highly conserved among the plant FMOs.One such motif presumably binds to flavin adenine dinucleotide(FAD) cofactor and the other binds to nicotinamide adenine dinucleotide phosphate (NADPH).We also identified the Ser139 to Phe conversion in yuc1,a mutation that is located between the two nucleotide-binding sites.By analyzing a series of yuc1 mutants,we identified key residues and motifs essential for the functions of YUC1 FMO.

  19. To control and to be controlled – understanding the Arabidopsis SLIM1 function in sulfur deficiency through comprehensive investigation of the EIL protein family.

    Directory of Open Access Journals (Sweden)

    Anna eWawrzyńska

    2014-10-01

    Full Text Available SSLIM1, a member of the EIN3-like (EIL family of transcription factors in Arabidopsis, is the regulator of many sulfur-deficiency responsive genes. Among the five other proteins of the family, three regulate ethylene responses and two have unassigned functions. Contrary to the well-defined ethylene signaling, the pathway leading from sensing sulfate status to the activation of its acquisition via SLIM1 is completely unknown. SLIM1 binds to the 20 nt-long specific UPE-box sequence; however, it also recognizes the shorter TEIL sequence, unique for the whole EIL family. SLIM1 takes part in the upregulation and downregulation of various sulfur metabolism genes, but also it controls the degradation of glucosinolates under sulfur deficient conditions. Besides facilitating the increased flux through the sulfate assimilation pathway, SLIM1 induces microRNA395, specifically targeting ATP sulfurylases and a low-affinity sulfate transporter, SULTR2;1, thus affecting sulfate translocation to the shoot. Here, we briefly review the identification, structural characteristics and molecular function of SLIM1 from the perspective of the whole EIL protein family.

  20. bHLH106 Integrates Functions of Multiple Genes through Their G-Box to Confer Salt Tolerance on Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Aftab Ahmad

    Full Text Available An activation-tagging methodology was applied to dedifferentiated calli of Arabidopsis to identify new genes involved in salt tolerance. This identified salt tolerant callus 8 (stc8 as a gene encoding the basic helix-loop-helix transcription factor bHLH106. bHLH106-knockout (KO lines were more sensitive to NaCl, KCl, LiCl, ABA, and low temperatures than the wild-type. Back-transformation of the KO line rescued its phenotype, and over-expression (OX of bHLH106 in differentiated plants exhibited tolerance to NaCl. Green fluorescent protein (GFP fused with bHLH106 revealed that it was localized to the nucleus. Prepared bHLH106 protein was subjected to electrophoresis mobility shift assays against E-box sequences (5'-CANNTG-3'. The G-box sequence 5'-CACGTG-3' had the strongest interaction with bHLH106. bHLH106-OX lines were transcriptomically analyzed, and resultant up- and down-regulated genes selected on the criterion of presence of a G-box sequence. There were 198 genes positively regulated by bHLH106 and 36 genes negatively regulated; these genes possessed one or more G-box sequences in their promoter regions. Many of these genes are known to be involved in abiotic stress response. It is concluded that bHLH106 locates at a branching point in the abiotic stress response network by interacting directly to the G-box in genes conferring salt tolerance on plants.

  1. Functional analysis of the cellulose synthase-like genes CSLD1, CSLD2 and CSLD4 in tip-growing arabidopsis cells

    DEFF Research Database (Denmark)

    Bernal Giraldo, Adriana Jimena; Yoo, Cheol-Min; Mutwil, Marek;

    2008-01-01

    for insertions in these genes were partially rescued by reduced temperature growth. However, this was not the case for a double mutant homozygous for insertions in both CSLD2 and CSLD3, suggesting that there may be partial redundancy in the functions of these genes. Mutants in CSLD1 and CSLD4 had a defect......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 rupturing late in development. Remarkably, though, it was often the case that in CSLD2 mutants, tip growth...

  2. Functional and evolutionary analysis of DXL1, a non-essential gene encoding a 1-deoxy-D-xylulose 5-phosphate synthase like protein in Arabidopsis thaliana.

    Science.gov (United States)

    Carretero-Paulet, Lorenzo; Cairó, Albert; Talavera, David; Saura, Andreu; Imperial, Santiago; Rodríguez-Concepción, Manuel; Campos, Narciso; Boronat, Albert

    2013-07-15

    The synthesis of 1-deoxy-D-xylulose 5-phosphate (DXP), catalyzed by the enzyme DXP synthase (DXS), represents a key regulatory step of the 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway for isoprenoid biosynthesis. In plants DXS is encoded by small multigene families that can be classified into, at least, three specialized subfamilies. Arabidopsis thaliana contains three genes encoding proteins with similarity to DXS, including the well-known DXS1/CLA1 gene, which clusters within subfamily I. The remaining proteins, initially named DXS2 and DXS3, have not yet been characterized. Here we report the expression and functional analysis of A. thaliana DXS2. Unexpectedly, the expression of DXS2 failed to rescue Escherichia coli and A. thaliana mutants defective in DXS activity. Coherently, we found that DXS activity was negligible in vitro, being renamed as DXL1 following recent nomenclature recommendation. DXL1 is targeted to plastids as DXS1, but shows a distinct expression pattern. The phenotypic analysis of a DXL1 defective mutant revealed that the function of the encoded protein is not essential for growth and development. Evolutionary analyses indicated that DXL1 emerged from DXS1 through a recent duplication apparently specific of the Brassicaceae lineage. Divergent selective constraints would have affected a significant fraction of sites after diversification of the paralogues. Furthermore, amino acids subjected to divergent selection and likely critical for functional divergence through the acquisition of a novel, although not yet known, biochemical function, were identified. Our results provide with the first evidences of functional specialization at both the regulatory and biochemical level within the plant DXS family.

  3. Terpene Specialized Metabolism in Arabidopsis thaliana

    OpenAIRE

    Tholl, Dorothea; Lee, Sungbeom

    2011-01-01

    Terpenes constitute the largest class of plant secondary (or specialized) metabolites, which are compounds of ecological function in plant defense or the attraction of beneficial organisms. Using biochemical and genetic approaches, nearly all Arabidopsis thaliana (Arabidopsis) enzymes of the core biosynthetic pathways producing the 5-carbon building blocks of terpenes have been characterized and closer insight has been gained into the transcriptional and posttranscriptional/translational mech...

  4. The lumen-facing domain is important for the biological function and organelle-to-organelle movement of bZIP28 during ER stress in Arabidopsis.

    Science.gov (United States)

    Sun, Le; Lu, Sun-Jie; Zhang, Shuang-Shuang; Zhou, Shun-Fan; Sun, Ling; Liu, Jian-Xiang

    2013-09-01

    The membrane-associated transcription factor, bZIP28, is relocated from the endoplasmic reticulum (ER) to the Golgi and proteolytically released from the membrane mediated by two proteases, S1P and S2P, in response to ER stress in Arabidopsis. The activated N-terminal domain recruits nuclear factor Y (NF-Y) subunits in the nucleus to regulate ER stress downstream genes. Little is known about the functions of the bZIP28 C-terminal lumen-facing domain. Here, we provide novel insights into how the ER lumen-facing domain affects the biological function and organelle-to-organelle movement of bZIP28 in the ER stress response. First, we demonstrated the functional redundancy of bZIP28 and bZIP60 by generation and analysis of the bZIP28 and bZIP60 double mutant zip28zip60. Subsequent genetic complementation experiments in zip28zip60 background with deletions on bZIP28 lumen-facing domain highlighted the importance of lumen-facing domain for its in vivo function of bZIP28 in the ER stress response. The protein subcellular localization and Western blotting results further revealed that the bZIP28 lumen-facing domain contains ER retention signal which is important for the proteolytic activation of bZIP28. Thus, the bZIP28 lumen-facing C-terminus plays important roles in the ER-to-Golgi movement of bZIP28, which may contribute to the sensing of the ER stress.

  5. Structure-Function Relationship of a Plant NCS1 Member – Homology Modeling and Mutagenesis Identified Residues Critical for Substrate Specificity of PLUTO, a Nucleobase Transporter from Arabidopsis

    OpenAIRE

    Sandra Witz; Pankaj Panwar; Markus Schober; Johannes Deppe; Farhan Ahmad Pasha; Joanne Lemieux, M; Torsten Möhlmann

    2014-01-01

    Plastidic uracil salvage is essential for plant growth and development. So far, PLUTO, the plastidic nucleobase transporter from Arabidopsis thaliana is the only known uracil importer at the inner plastidic membrane which represents the permeability barrier of this organelle. We present the first homology model of PLUTO, the sole plant NCS1 member from Arabidopsis based on the crystal structure of the benzyl hydantoin transporter MHP1 from Microbacterium liquefaciens and validated by molecula...

  6. Arabidopsis: an adequate model for dicot root systems?

    OpenAIRE

    Zobel, Richard W.

    2016-01-01

    The Arabidopsis root system is frequently considered to have only three classes of root: primary, lateral, and adventitious. Research with other plant species has suggested up to 8 different developmental/functional classes of root for a given plant root system. If Arabidopsis has only three classes of root, it may not be an adequate model for eudicot plant root systems. Recent research, however, can be interpreted to suggest that pre-flowering Arabidopsis does have at least five (5) of th...

  7. Arabidopsis: An Adequate Model for Dicot Root Systems?

    OpenAIRE

    Zobel, Richard W.

    2016-01-01

    The Arabidopsis root system is frequently considered to have only three classes of root: primary, lateral, and adventitious. Research with other plant species has suggested up to eight different developmental/functional classes of root for a given plant root system. If Arabidopsis has only three classes of root, it may not be an adequate model for eudicot plant root systems. Recent research, however, can be interpreted to suggest that pre-flowering Arabidopsis does have at least five (5) of t...

  8. The Arabidopsis NF-YA3 and NF-YA8 genes are functionally redundant and are required in early embryogenesis.

    Directory of Open Access Journals (Sweden)

    Monica Fornari

    Full Text Available Nuclear factor Y (NF-Y is a trimeric transcription factor composed of three distinct subunits called NF-YA, NF-YB and NF-YC. In Arabidopsis thaliana, NF-Y subunits are known to play roles in many processes, such as gametogenesis, embryogenesis, seed development, drought resistance, ABA signaling, flowering time, primary root elongation, Endoplasmic Reticulum (ER stress response and blue light responses. Here, we report that the closely related NF-YA3 and NF-YA8 genes control early embryogenesis. Detailed GUS and in situ analyses showed that NF-YA3 and NF-YA8 are expressed in vegetative and reproductive tissues with the highest expression being during embryo development from the globular to the torpedo embryo stage. Plants from the nf-ya3 and nf-ya8 single mutants do not display any obvious phenotypic alteration, whereas nf-ya3 nf-ya8 double mutants are embryo lethal. Morphological analyses showed that the nf-ya3 nf-ya8 embryos fail to undergo to the heart stage and develop into abnormal globular embryos with both proembryo and suspensor characterized by a disordered cell cluster with an irregular shape, suggesting defects in embryo development. The suppression of both NF-YA3 and NF-YA8 gene expression by RNAi experiments resulted in defective embryos that phenocopied the nf-ya3 nf-ya8 double mutants, whereas complementation experiments partially rescued the abnormal globular nf-ya3 nf-ya8 embryos, confirming that NF-YA3 and NF-YA8 are required in early embryogenesis. Finally, the lack of GFP expression of the auxin responsive DR5rev::GFP marker line in double mutant embryos suggested that mutations in both NF-YA3 and NF-YA8 affect auxin response in early developing embryos. Our findings indicate that NF-YA3 and NF-YA8 are functionally redundant genes required in early embryogenesis of Arabidopsis thaliana.

  9. Global metabolic profiling of Arabidopsis Polyamine Oxidase 4 (AtPAO4 loss-of-function mutants exhibiting delayed dark-induced senescence

    Directory of Open Access Journals (Sweden)

    Miren Iranzu Sequera-Mutiozabal

    2016-02-01

    Full Text Available Early and more recent studies have suggested that some polyamines (PAs, and particularly spermine (Spm, exhibit anti-senescence properties in plants. In this work, we have investigated the role of Arabidopsis Polyamine Oxidase 4 (PAO4, encoding a PA back-conversion oxidase, during dark-induced senescence. Two independent PAO4 (pao4-1 and pao4-2 loss-of-function mutants have been found that accumulate 10-fold higher Spm, and this associated with delayed entry into senescence under dark conditions. Mechanisms underlying pao4 delayed senescence have been studied using global metabolic profiling by GC-TOF/MS. pao4 mutants exhibit constitutively higher levels of important metabolites involved in redox regulation, central metabolism and signaling that support a priming status against oxidative stress. During senescence, interactions between PAs and oxidative, sugar and nitrogen metabolism have been detected that additively contribute to delayed entry into senescence. Our results indicate the occurrence of metabolic interactions between PAs, particularly Spm, with cell oxidative balance and transport/biosynthesis of amino acids as a strategy to cope with oxidative damage produced during senescence.

  10. A chaperone function of NO CATALASE ACTIVITY1 is required to maintain catalase activity and for multiple stress responses in Arabidopsis.

    Science.gov (United States)

    Li, Jing; Liu, Juntao; Wang, Guoqiang; Cha, Joon-Yung; Li, Guannan; Chen, She; Li, Zhen; Guo, Jinghua; Zhang, Caiguo; Yang, Yongqing; Kim, Woe-Yeon; Yun, Dae-Jin; Schumaker, Karen S; Chen, Zhongzhou; Guo, Yan

    2015-03-01

    Catalases are key regulators of reactive oxygen species homeostasis in plant cells. However, the regulation of catalase activity is not well understood. In this study, we isolated an Arabidopsis thaliana mutant, no catalase activity1-3 (nca1-3) that is hypersensitive to many abiotic stress treatments. The mutated gene was identified by map-based cloning as NCA1, which encodes a protein containing an N-terminal RING-finger domain and a C-terminal tetratricopeptide repeat-like helical domain. NCA1 interacts with and increases catalase activity maximally in a 240-kD complex in planta. In vitro, NCA1 interacts with CATALASE2 (CAT2) in a 1:1 molar ratio, and the NCA1 C terminus is essential for this interaction. CAT2 activity increased 10-fold in the presence of NCA1, and zinc ion binding of the NCA1 N terminus is required for this increase. NCA1 has chaperone protein activity that may maintain the folding of catalase in a functional state. NCA1 is a cytosol-located protein. Expression of NCA1 in the mitochondrion of the nca1-3 mutant does not rescue the abiotic stress phenotypes of the mutant, while expression in the cytosol or peroxisome does. Our results suggest that NCA1 is essential for catalase activity.

  11. A gain-of-function mutation in Msl10 triggers cell death and wound-induced hyperaccumulation of jasmonic acid in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Yan Zou; Jian-Min Zhou; Satya Chintamanani; Ping He; Hirotada Fukushige; Liping Yu; Meiyu Shao; Lihuang Zhu; David F Hildebrand; Xiaoyan Tang

    2016-01-01

    Jasmonates (JAs) are rapidly induced after wound-ing and act as key regulators for wound induced signaling pathway. However, what perceives the wound signal and how that triggers JA biosynthesis remains poorly understood. To identify components involved in Arabidopsis wound and JA signaling pathway, we screened for mutants with abnormal expression of a luciferase reporter, which is under the control of a wound-responsive promoter of an ethylene response factor (ERF) transcription factor gene, RAP2.6 (Related to APetala 2.6). The rea1 (RAP2.6 expresser in shoot apex) mutant constitutively expressed the RAP2.6-LUC reporter gene in young leaves. Along with the typical JA phenotypes including shorter petioles, loss of apical dominance, accumulation of anthocyanin pig-ments and constitutive expression of JA response gene, rea1 plants also displayed cell death and accumulated high levels of JA in response to wounding. The phenotype of rea1 mutant is caused by a gain-of-function mutation in the C-terminus of a mechanosensitive ion channel MscS-like 10 (MSL10). MSL10 is localized in the plasma membrane and is expressed predom-inantly in root tip, shoot apex and vascular tissues. These results suggest that MSL10 is involved in the wound-triggered early signal transduction pathway and possibly in regulating the positive feedback synthesis of JA.

  12. Conservation and Diversification of the SHR-SCR-SCL23 Regulatory Network in the Development of the Functional Endodermis in Arabidopsis Shoots.

    Science.gov (United States)

    Yoon, Eun Kyung; Dhar, Souvik; Lee, Mi-Hyun; Song, Jae Hyo; Lee, Shin Ae; Kim, Gyuree; Jang, Sejeong; Choi, Ji Won; Choe, Jeong-Eun; Kim, Jeong Hoe; Lee, Myeong Min; Lim, Jun

    2016-08-01

    Development of the functional endodermis of Arabidopsis thaliana roots is controlled, in part, by GRAS transcription factors, namely SHORT-ROOT (SHR), SCARECROW (SCR), and SCARECROW-LIKE 23 (SCL23). Recently, it has been shown that the SHR-SCR-SCL23 regulatory module is also essential for specification of the endodermis (known as the bundle sheath) in leaves. Nevertheless, compared with what is known about the role of the SHR-SCR-SCL23 regulatory network in roots, the molecular interactions of SHR, SCR, and SCL23 are much less understood in shoots. Here, we show that SHR forms protein complexes with SCL23 to regulate transcription of SCL23 in shoots, similar to the regulation mode of SCR expression. Our results indicate that SHR acts as master regulator to directly activate the expression of SCR and SCL23. In the SHR-SCR-SCL23 network, we found a previously uncharacterized negative feedback loop whereby SCL23 modulates SHR levels. Through molecular, genetic, physiological, and morphological analyses, we also reveal that the SHR-SCR-SCL23 module plays a key role in the formation of the endodermis (known as the starch sheath) in hypocotyls. Taken together, our results provide new insights into the regulatory role of the SHR-SCR-SCL23 network in the endodermis development in both roots and shoots. PMID:27353361

  13. The Arabidopsis P4-ATPase ALA3 localizes to the golgi and requires a beta-subunit to function in lipid translocation and secretory vesicle formation.

    Science.gov (United States)

    Poulsen, Lisbeth Rosager; López-Marqués, Rosa Laura; McDowell, Stephen C; Okkeri, Juha; Licht, Dirk; Schulz, Alexander; Pomorski, Thomas; Harper, Jeffrey F; Palmgren, Michael Gjedde

    2008-03-01

    Vesicle budding in eukaryotes depends on the activity of lipid translocases (P(4)-ATPases) that have been implicated in generating lipid asymmetry between the two leaflets of the membrane and in inducing membrane curvature. We show that Aminophospholipid ATPase3 (ALA3), a member of the P(4)-ATPase subfamily in Arabidopsis thaliana, localizes to the Golgi apparatus and that mutations of ALA3 result in impaired growth of roots and shoots. The growth defect is accompanied by failure of the root cap to release border cells involved in the secretion of molecules required for efficient root interaction with the environment, and ala3 mutants are devoid of the characteristic trans-Golgi proliferation of slime vesicles containing polysaccharides and enzymes for secretion. In yeast complementation experiments, ALA3 function requires interaction with members of a novel family of plant membrane-bound proteins, ALIS1 to ALIS5 (for ALA-Interacting Subunit), and in this host ALA3 and ALIS1 show strong affinity for each other. In planta, ALIS1, like ALA3, localizes to Golgi-like structures and is expressed in root peripheral columella cells. We propose that the ALIS1 protein is a beta-subunit of ALA3 and that this protein complex forms an important part of the Golgi machinery required for secretory processes during plant development.

  14. RNA Polymerase V Functions in Arabidopsis Interphase Heterochromatin Organization Independently of the 24-nt siRNA-Directed DNA Methylation Pathway

    Institute of Scientific and Technical Information of China (English)

    Olga Pontes; Pedro Costa-Nunes; Paul Vithayathil; Craig S.Pikaard

    2009-01-01

    In Arabidopsis,pericentromeric repeats,retroelements,and silenced rRNA genes are assembled into heterochromatin within nuclear structures known as chromocenters.The mechanisms governing higher-order heterochromatin organization are poorly understood but 24-nt small interfering RNAs (siRNAs) are known to play key roles in heterochromatin formation.Nuclear RNA polymerase IV (Pol IV),RNA-DEPENDENT RNA POLYMERASE 2 (RDR2),and DICER-LIKE 3 (DCL3) are required for biogenesis of 24-nt siRNAs that associate with ARGONAUTE 4 (AGO4).Nuclear RNA polymerase V (Pol V) collaborates with DRD1 (DEFICIENT IN RNA-DEPENDENT DNA METHYLATION 1) to generate transcripts at heterochromatic loci that are hypothesized to bind to siRNA-AGO4 complexes and subsequently recruit the de-novo DNA methylation and/or histone modifying machinery.Here,we report that decondensation of the major pericentromeric repeats and depletion of the heterochromatic mark histone H3 lysine 9 dimethylation at chromocenters occurs specifically in pol V and drd1 mutants.Disruption of pericentromeric repeats condensation is coincident with transcriptional reactivation of specific classes of pericentromeric 180-bp repeats.We further demonstrate that Pol V functions independently of Pol IV,RDR2,and DCL3-mediated siRNA production to affect interphase heterochromatin organization,possibly by involving RNAs that recruit structural or chromatin-modifying proteins.

  15. A gain-of-function mutation in Msl10 triggers cell death and wound-induced hyperaccumulation of jasmonic acid in Arabidopsis.

    Science.gov (United States)

    Zou, Yan; Chintamanani, Satya; He, Ping; Fukushige, Hirotada; Yu, Liping; Shao, Meiyu; Zhu, Lihuang; Hildebrand, David F; Tang, Xiaoyan; Zhou, Jian-Min

    2016-06-01

    Jasmonates (JAs) are rapidly induced after wounding and act as key regulators for wound induced signaling pathway. However, what perceives the wound signal and how that triggers JA biosynthesis remains poorly understood. To identify components involved in Arabidopsis wound and JA signaling pathway, we screened for mutants with abnormal expression of a luciferase reporter, which is under the control of a wound-responsive promoter of an ethylene response factor (ERF) transcription factor gene, RAP2.6 (Related to APetala 2.6). The rea1 (RAP2.6 expresser in shoot apex) mutant constitutively expressed the RAP2.6-LUC reporter gene in young leaves. Along with the typical JA phenotypes including shorter petioles, loss of apical dominance, accumulation of anthocyanin pigments and constitutive expression of JA response gene, rea1 plants also displayed cell death and accumulated high levels of JA in response to wounding. The phenotype of rea1 mutant is caused by a gain-of-function mutation in the C-terminus of a mechanosensitive ion channel MscS-like 10 (MSL10). MSL10 is localized in the plasma membrane and is expressed predominantly in root tip, shoot apex and vascular tissues. These results suggest that MSL10 is involved in the wound-triggered early signal transduction pathway and possibly in regulating the positive feedback synthesis of JA. PMID:26356550

  16. A Gain-of-Function Mutation in IAA7/AXR2 Confers Late Flowering under Short-day Light in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Yan-Xia Mai; Long Wang; Hong-Quan Yang

    2011-01-01

    Floral initiation is a major step in the life cycle of plants, which is influenced by photoperiod, temperature,and phytohormones, such as gibberellins (GAs). It is known that GAs promote floral initiation under short-day light conditions (SDs) by regulating the floral meristem-identity gene LEAFY (LFY) and the flowering-time gene SUPPRESSOR OF OVEREXPRESSlON OF CO 1 (SOC1). We have defined the role of the auxin signaling component INDOLE-3-ACETIC ACID 7 (IAA7)/AUXIN RESISTANT 2 (AXR2) in the regulation of flowering time in Arabidopsis thaliana. We demonstrate that the gain-of-function mutant of IAA7/AXR2, axr2-1, flowers late under SDs. The exogenous application of GAs rescued the late flowering phenotype of axr2-1 plants. The expression of the GA20 oxidase (GA20ox) genes, GA20ox1 and GA20ox2,was reduced in axr2-1 plants, and the levels of both LFY and SOC1 transcripts were reduced in axr2-1 mutants under SDs. Furthermore, the overexpression of SOC1 or LFY in axr2-1 mutants rescued the late flowering phenotype under SDs. Our results suggest that IAA7/AXR2 might act to inhibit the timing of floral transition under SDs, at least in part, by negatively regulating the expressions of the GA20ox1 and GA20ox2 genes.

  17. Conservation and Diversification of the SHR-SCR-SCL23 Regulatory Network in the Development of the Functional Endodermis in Arabidopsis Shoots.

    Science.gov (United States)

    Yoon, Eun Kyung; Dhar, Souvik; Lee, Mi-Hyun; Song, Jae Hyo; Lee, Shin Ae; Kim, Gyuree; Jang, Sejeong; Choi, Ji Won; Choe, Jeong-Eun; Kim, Jeong Hoe; Lee, Myeong Min; Lim, Jun

    2016-08-01

    Development of the functional endodermis of Arabidopsis thaliana roots is controlled, in part, by GRAS transcription factors, namely SHORT-ROOT (SHR), SCARECROW (SCR), and SCARECROW-LIKE 23 (SCL23). Recently, it has been shown that the SHR-SCR-SCL23 regulatory module is also essential for specification of the endodermis (known as the bundle sheath) in leaves. Nevertheless, compared with what is known about the role of the SHR-SCR-SCL23 regulatory network in roots, the molecular interactions of SHR, SCR, and SCL23 are much less understood in shoots. Here, we show that SHR forms protein complexes with SCL23 to regulate transcription of SCL23 in shoots, similar to the regulation mode of SCR expression. Our results indicate that SHR acts as master regulator to directly activate the expression of SCR and SCL23. In the SHR-SCR-SCL23 network, we found a previously uncharacterized negative feedback loop whereby SCL23 modulates SHR levels. Through molecular, genetic, physiological, and morphological analyses, we also reveal that the SHR-SCR-SCL23 module plays a key role in the formation of the endodermis (known as the starch sheath) in hypocotyls. Taken together, our results provide new insights into the regulatory role of the SHR-SCR-SCL23 network in the endodermis development in both roots and shoots.

  18. The arabidopsis wall associated kinase-like 10 gene encodes a functional guanylyl cyclase and is co-expressed with pathogen defense related genes

    KAUST Repository

    Meier, Stuart

    2010-01-26

    Background: Second messengers have a key role in linking environmental stimuli to physiological responses. One such messenger, guanosine 3?,5?-cyclic monophosphate (cGMP), has long been known to be an essential signaling molecule in many different physiological processes in higher plants, including biotic stress responses. To date, however, the guanylyl cyclase (GC) enzymes that catalyze the formation of cGMP from GTP have largely remained elusive in higher plants. Principal Findings: We have identified an Arabidopsis receptor type wall associated kinase-like molecule (AtWAKL10) as a candidate GC and provide experimental evidence to show that the intracellular domain of AtWAKL10431-700 can generate cGMP in vitro. Further, we also demonstrate that the molecule has kinase activity indicating that AtWAKL10 is a twin-domain catalytic protein. A co-expression and stimulus-specific expression analysis revealed that AtWAKL10 is consistently coexpressed with well characterized pathogen defense related genes and along with these genes is induced early and sharply in response to a range of pathogens and their elicitors. Conclusions: We demonstrate that AtWAKL10 is a twin-domain, kinase-GC signaling molecule that may function in biotic stress responses that are critically dependent on the second messenger cGMP. © 2010 Meier et al.

  19. Functional analysis of U1-70K interacting SR proteins in pre-mRNA splicing in Arabidopsis

    Energy Technology Data Exchange (ETDEWEB)

    A.S.N. Reddy

    2008-11-25

    Proteins of a serine/arginine-rich (SR) family are part of the spliceosome and are implicated in both constitutive and alternative splicing of pre-mRNAs. With the funding from DOE we have been studying alternative of splicing of genes encoding serine/arginine-rich (SR) proteins and the roles of SR proteins that interact with U1-70K in regulating basic and alternative splicing. Alternative splicing of pre-mRNAs of Arabidopsis serine/arginine-rich proteins and its regulation by hormones and stresses: We analyzed the splicing of all 19 Arabidopsis genes in different tissues, during different seedling stages and in response to various hormonal and stress treatments. Remarkably, about 90 different transcripts are produced from 15 SR genes, thereby increasing the transcriptome complexity of SR genes by about five fold. Using the RNA isolated from polysomes we have shown that most of the splice variants are recruited for translation. Alternative splicing of some SR genes is controlled in a developmental and tissue-specific manner (Palusa et al., 2007). Interestingly, among the various hormones and abiotic stresses tested, temperature stress (cold and heat) and ultraviolet light dramatically altered alternative splicing of pre-mRNAs of several SR genes whereas hormones altered the splicing of only two SR genes (Palusa et al., 2007). Localization and dynamics of a novel serine/arginine-rich protein that interacts with U1-70K: We analyzed the intranuclear movement of SR45 fused to GFP by fluorescence recovery after photobleaching (FRAP) and fluorescence loss in photobleaching (FLIP). We demonstrate that the movement of GFP-SR45 is ATP-dependent. Interestingly, inhibition of transcription or phosphorylation slowed the mobility of GFP-SR45 (Ali et al., 2006). Our studies have revealed that the nuclear localization signals are located in arg/ser-rich domains (RS) 1 and 2, whereas the speckle targeting signals are exclusively present in RS2 (Ali et al., 2006). The regulation of

  20. Functional analysis of U1-70K interacting SR proteins in pre-mRNA splicing in Arabidopsis

    International Nuclear Information System (INIS)

    Proteins of a serine/arginine-rich (SR) family are part of the spliceosome and are implicated in both constitutive and alternative splicing of pre-mRNAs. With the funding from DOE we have been studying alternative of splicing of genes encoding serine/arginine-rich (SR) proteins and the roles of SR proteins that interact with U1-70K in regulating basic and alternative splicing. Alternative splicing of pre-mRNAs of Arabidopsis serine/arginine-rich proteins and its regulation by hormones and stresses: We analyzed the splicing of all 19 Arabidopsis genes in different tissues, during different seedling stages and in response to various hormonal and stress treatments. Remarkably, about 90 different transcripts are produced from 15 SR genes, thereby increasing the transcriptome complexity of SR genes by about five fold. Using the RNA isolated from polysomes we have shown that most of the splice variants are recruited for translation. Alternative splicing of some SR genes is controlled in a developmental and tissue-specific manner (Palusa et al., 2007). Interestingly, among the various hormones and abiotic stresses tested, temperature stress (cold and heat) and ultraviolet light dramatically altered alternative splicing of pre-mRNAs of several SR genes whereas hormones altered the splicing of only two SR genes (Palusa et al., 2007). Localization and dynamics of a novel serine/arginine-rich protein that interacts with U1-70K: We analyzed the intranuclear movement of SR45 fused to GFP by fluorescence recovery after photobleaching (FRAP) and fluorescence loss in photobleaching (FLIP). We demonstrate that the movement of GFP-SR45 is ATP-dependent. Interestingly, inhibition of transcription or phosphorylation slowed the mobility of GFP-SR45 (Ali et al., 2006). Our studies have revealed that the nuclear localization signals are located in arg/ser-rich domains (RS) 1 and 2, whereas the speckle targeting signals are exclusively present in RS2 (Ali et al., 2006). The regulation of

  1. Genome-Wide Analysis of PAPS1-Dependent Polyadenylation Identifies Novel Roles for Functionally Specialized Poly(A Polymerases in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Christian Kappel

    2015-08-01

    Full Text Available The poly(A tail at 3' ends of eukaryotic mRNAs promotes their nuclear export, stability and translational efficiency, and changes in its length can strongly impact gene expression. The Arabidopsis thaliana genome encodes three canonical nuclear poly(A polymerases, PAPS1, PAPS2 and PAPS4. As shown by their different mutant phenotypes, these three isoforms are functionally specialized, with PAPS1 modifying organ growth and suppressing a constitutive immune response. However, the molecular basis of this specialization is largely unknown. Here, we have estimated poly(A-tail lengths on a transcriptome-wide scale in wild-type and paps1 mutants. This identified categories of genes as particularly strongly affected in paps1 mutants, including genes encoding ribosomal proteins, cell-division factors and major carbohydrate-metabolic proteins. We experimentally verified two novel functions of PAPS1 in ribosome biogenesis and redox homoeostasis that were predicted based on the analysis of poly(A-tail length changes in paps1 mutants. When overlaying the PAPS1-dependent effects observed here with coexpression analysis based on independent microarray data, the two clusters of transcripts that are most closely coexpressed with PAPS1 show the strongest change in poly(A-tail length and transcript abundance in paps1 mutants in our analysis. This suggests that their coexpression reflects at least partly the preferential polyadenylation of these transcripts by PAPS1 versus the other two poly(A-polymerase isoforms. Thus, transcriptome-wide analysis of poly(A-tail lengths identifies novel biological functions and likely target transcripts for polyadenylation by PAPS1. Data integration with large-scale co-expression data suggests that changes in the relative activities of the isoforms are used as an endogenous mechanism to co-ordinately modulate plant gene expression.

  2. The eta7/csn3-3 auxin response mutant of Arabidopsis defines a novel function for the CSN3 subunit of the COP9 signalosome.

    Directory of Open Access Journals (Sweden)

    He Huang

    Full Text Available The COP9 signalosome (CSN is an eight subunit protein complex conserved in all higher eukaryotes. In Arabidopsis thaliana, the CSN regulates auxin response by removing the ubiquitin-like protein NEDD8/RUB1 from the CUL1 subunit of the SCF(TIR1/AFB ubiquitin-ligase (deneddylation. Previously described null mutations in any CSN subunit result in the pleiotropic cop/det/fus phenotype and cause seedling lethality, hampering the study of CSN functions in plant development. In a genetic screen to identify enhancers of the auxin response defects conferred by the tir1-1 mutation, we identified a viable csn mutant of subunit 3 (CSN3, designated eta7/csn3-3. In addition to enhancing tir1-1 mutant phenotypes, the csn3-3 mutation alone confers several phenotypes indicative of impaired auxin signaling including auxin resistant root growth and diminished auxin responsive gene expression. Unexpectedly however, csn3-3 plants are not defective in either the CSN-mediated deneddylation of CUL1 or in SCF(TIR1-mediated degradation of Aux/IAA proteins. These findings suggest that csn3-3 is an atypical csn mutant that defines a novel CSN or CSN3-specific function. Consistent with this possibility, we observe dramatic differences in double mutant interactions between csn3-3 and other auxin signaling mutants compared to another weak csn mutant, csn1-10. Lastly, unlike other csn mutants, assembly of the CSN holocomplex is unaffected in csn3-3 plants. However, we detected a small CSN3-containing protein complex that is altered in csn3-3 plants. We hypothesize that in addition to its role in the CSN as a cullin deneddylase, CSN3 functions in a distinct protein complex that is required for proper auxin signaling.

  3. Arabidopsis MKS1 is involved in basal immunity and requires an intact N-terminal domain for proper function.

    Directory of Open Access Journals (Sweden)

    Klaus Petersen

    Full Text Available BACKGROUND: Innate immune signaling pathways in animals and plants are regulated by mitogen-activated protein kinase (MAPK cascades. MAP kinase 4 (MPK4 functions downstream of innate immune receptors via a nuclear substrate MKS1 to regulate the activity of the WRKY33 transcription factor, which in turn controls the production of anti-microbial phytoalexins. METHODOLOGY/PRINCIPAL FINDINGS: We investigate the role of MKS1 in basal resistance and the importance of its N- and C-terminal domains for MKS1 function. We used the information that mks1 loss-of-function partially suppresses the mpk4 loss-of-function phenotype, and that transgenic expression of functional MKS1 in mpk4/mks1 double mutants reverted the mpk4 dwarf phenotype. Transformation of mks1/mpk4 with mutant versions of MKS1 constructs showed that a single amino acid substitution in a putative MAP kinase docking domain, MKS1-L32A, or a truncated MKS1 version unable to interact with WRKY33, were deficient in reverting the double mutant to the mpk4 phenotype. These results demonstrate functional requirement in MKS1 for the interaction with MPK4 and WRKY33. In addition, nuclear localization of MKS1 was shown to depend on an intact N-terminal domain. Furthermore, loss-of-function mks1 mutants exhibited increased susceptibility to strains of Pseudomonas syringae and Hyaloperonospora arabidopsidis, indicating that MKS1 plays a role in basal defense responses. CONCLUSIONS: Taken together, our results indicate that MKS1 function and subcellular location requires an intact N-terminus important for both MPK4 and WRKY33 interactions.

  4. OsSFR6 is a functional rice orthologue of SENSITIVE TO FREEZING-6 and can act as a regulator of COR gene expression, osmotic stress and freezing tolerance in Arabidopsis.

    Science.gov (United States)

    Wathugala, Deepthi L; Richards, Shane A; Knight, Heather; Knight, Marc R

    2011-09-01

    The Arabidopsis protein SENSITIVE TO FREEZING-6 (AtSFR6) is required for cold- and drought-inducible expression of COLD-ON REGULATED (COR) genes and, as a consequence, AtSFR6 is essential for osmotic stress and freezing tolerance in Arabidopsis. Therefore, orthologues of AtSFR6 in crop species represent important candidate targets for future manipulation of stress tolerance. We identified and cloned a homologue of AtSFR6 from rice (Oryza sativa), OsSFR6, and confirmed its orthology in Arabidopsis. OsSFR6 was identified by homology searches, and a full-length coding region isolated using reverse transcription polymerase chain reaction (RT-PCR) from Oryza sativa cDNA. To test for orthology, OsSFR6 was expressed in an Arabidopsis sfr6 loss-of-function mutant background, and restoration of wild-type phenotypes was assessed. Searching the rice genome revealed a single homologue of AtSFR6. Cloning and sequencing the OsSFR6 coding region showed OsSFR6 to have 61.7% identity and 71.1% similarity to AtSFR6 at the predicted protein sequence level. Expression of OsSFR6 in the atsfr6 mutant background restored the wild-type visible phenotype, as well as restoring wild-type levels of COR gene expression and tolerance of osmotic and freezing stresses. OsSFR6 is an orthologue of AtSFR6, and thus a target for future manipulation to improve tolerance to osmotic and other abiotic stresses. PMID:21585388

  5. Arabidopsis MKS1 is involved in basal immunity and requires an intact N-terminal domain for proper function

    DEFF Research Database (Denmark)

    Petersen, Klaus; Qiu, Jin-Long; Lütje, Juri;

    2010-01-01

    Innate immune signaling pathways in animals and plants are regulated by mitogen-activated protein kinase (MAPK) cascades. MAP kinase 4 (MPK4) functions downstream of innate immune receptors via a nuclear substrate MKS1 to regulate the activity of the WRKY33 transcription factor, which in turn...

  6. Functional characterisation of an Arabidopsis gene strongly induced by ionising radiation: the gene coding the poly(ADP-ribose)polymerase-1 (AthPARP-1)

    International Nuclear Information System (INIS)

    Arabidopsis thaliana, the model-system in plant genetics, has been used to study the responses to DNA damage, experimentally introduced by γ-irradiation. We have characterised a radiation-induced gene coding a 111 kDa protein, AthPARP-1, homologous to the human poly(ADP-ribose)polymerase-1 (hPARP-1). As hPARP-1 is composed by three functional domain with characteristic motifs, AthPARP-1 binds to DNA bearing single-strand breaks and shows DNA damage-dependent poly(ADP-ribosyl)ation. The preferential expression of AthPARP-1 in mitotically active tissues is in agreement with a potential role in the maintenance of genome integrity during DNA replication, as proposed for its human counterpart. Transcriptional gene activation by ionising radiation of AthPARP-1 and AthPARP-2 genes is to date plant specific activation. Our expression analyses after exposure to various stress indicate that 1) AthPARP-1 and AthPARP-2 play an important role in the response to DNA lesions, particularly they are activated by genotoxic agents implicating the BER DNA repair pathway 2) AthPARP-2 gene seems to play an additional role in the signal transduction induced by oxidative stress 3) the observed expression profile of AthPARP-1 is in favour of the regulation of AthPARP-1 gene expression at the level of transcription and translation. This mode of regulation of AthPARP-1 protein biosynthesis, clearly distinct from that observed in animals, needs the implication of a so far unidentified transcription factor that is activated by the presence of DNA lesions. The major outcome of this work resides in the isolation and characterisation of such new transcription factor, which will provide new insight on the regulation of plant gene expression by genotoxic stress. (author)

  7. Two Hydroxyproline Galactosyltransferases, GALT5 and GALT2, Function in Arabinogalactan-Protein Glycosylation, Growth and Development in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Debarati Basu

    Full Text Available Hydroxyproline-O-galactosyltransferase (GALT initiates O-glycosylation of arabinogalactan-proteins (AGPs. We previously characterized GALT2 (At4g21060, and now report on functional characterization of GALT5 (At1g74800. GALT5 was identified using heterologous expression in Pichia and an in vitro GALT assay. Product characterization showed GALT5 specifically adds galactose to hydroxyproline in AGP protein backbones. Functions of GALT2 and GALT5 were elucidated by phenotypic analysis of single and double mutant plants. Allelic galt5 and galt2 mutants, and particularly galt2 galt5 double mutants, demonstrated lower GALT activities and reductions in β-Yariv-precipitated AGPs compared to wild type. Mutant plants showed pleiotropic growth and development phenotypes (defects in root hair growth, root elongation, pollen tube growth, flowering time, leaf development, silique length, and inflorescence growth, which were most severe in the double mutants. Conditional mutant phenotypes were also observed, including salt-hypersensitive root growth and root tip swelling as well as reduced inhibition of pollen tube growth and root growth in response to β-Yariv reagent. These mutants also phenocopy mutants for an AGP, SOS5, and two cell wall receptor-like kinases, FEI1 and FEI2, which exist in a genetic signaling pathway. In summary, GALT5 and GALT2 function as redundant GALTs that control AGP O-glycosylation, which is essential for normal growth and development.

  8. Contributions of Individual Amino Acid Residues to the Endogenous CLV3 Function in Shoot Apical Meristem Maintenance in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Xiu-Fen Song; Da-Li Yu; Ting-Ting Xu; Shi-Chao Ren; Peng Guo; Chun-Ming Liu

    2012-01-01

    As a peptide hormone,CLV3 restricts the stem cell number in shoot apical meristem (SAM) by interacting with CLV1/CLV2/CRN/RPK2 receptor complexes.To elucidate howthe function of the CLV3 peptide in SAM maintenance is established at the amino acid (AA) level,alanine substitutions were performed by introducing point mutations to individual residues in the peptide-coding region of CLV3 and its flanking sequences.Constructs carrying such substitutions,expressed under the control of CLV3 regulatory elements,were transformed to the clv3-2 null mutant to evaluate their efficiencies in complementing its defects in SAMs in vivo.These studies showed that aspartate-8,histidine-11,glycine-6,proline-4,arginine-1,and proline-9,arranged in an order of importance,were critical,while threonine-2,valine-3,serine-5,and the previously assigned hydroxylation and arabinosylation residue proline-7 were trivial for the endogenous CLV3 function in SAM maintenance.In contrast,substitutions of flanking residues did not impose much damage on CLV3.Complementation of different alanine-substituted constructs was confirmed by measurements of the sizes of SAMs and the WUS expression levels in transgenic plants.These studies established a complete contribution map of individual residues in the peptide-coding region of CLV3 for its function in SAM,which may help to understand peptide hormones in general.

  9. Mining the active proteome of Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Renier A. L. Van Der Hoorn

    2011-11-01

    Full Text Available Assigning functions to the >30.000 proteins encoded by the Arabidopsis genome is a challenging task of the Arabidopsis Functional Genomics Network. Although genome-wide technologies like proteomics and transcriptomics have generated a wealth of information that significantly accelerated gene annotation, protein activities are poorly predicted by transcript or protein levels as protein activities are post-translationally regulated. To directly display protein activities in Arabidopsis proteomes, we developed and applied Activity-based Protein Profiling (ABPP. ABPP is based on the use of small molecule probes that react with the catalytic residues of distinct protein classes in an activity-dependent manner. Labeled proteins are separated and detected from proteins gels and purified and identified by mass spectrometry. Using probes of six different chemotypes we have displayed of activities of 76 Arabidopsis proteins. These proteins represent over ten different protein classes that contain over 250 Arabidopsis proteins, including cysteine- serine- and metallo-proteases, lipases, acyltransferases, and the proteasome. We have developed methods for identification of in vivo labeled proteins using click-chemistry and for in vivo imaging with fluorescent probes. In vivo labeling has revealed novel protein activities and unexpected subcellular activities of the proteasome. Labeling of extracts displayed several differential activities e.g. of the proteasome during immune response and methylesterases during infection. These studies illustrate the power of ABPP to display the functional proteome and testify to a successful interdisciplinary collaboration involving chemical biology, organic chemistry and proteomics.

  10. A partial loss-of-function mutation in an Arabidopsis RNA polymerase III subunit leads to pleiotropic defects.

    Science.gov (United States)

    Johnson, Kaeli C M; Yu, Yu; Gao, Lei; Eng, Ryan C; Wasteneys, Geoffrey O; Chen, Xuemei; Li, Xin

    2016-04-01

    Plants employ five DNA-dependent RNA polymerases (Pols) in transcription. One of these polymerases, Pol III, has previously been reported to transcribe 5S rRNA, tRNAs, and a number of small RNAs. However, in-depth functional analysis is complicated by the fact that knockout mutations in Pol subunits are typically lethal. Here, we report the characterization of the first known viable Pol III subunit mutant,nrpc7-1 This mutant was originally isolated from a forward genetic screen designed to identify enhancers of the autoimmune mutantsnc1, which contains a gain-of-function mutation in a nucleotide-binding leucine-rich repeat (NLR) immune receptor-encoding gene. Thenrpc7-1mutation occurs in an intron-exon splice site and results in intron retention in someNRPC7transcripts. There is a global disruption in RNA equilibrium innrpc7-1, exemplified by the altered expression of a number of RNA molecules, some of which are not reported to be transcribed by Pol III. There are developmental defects associated with the mutation, as homozygous mutant plants are dwarf, have stunted roots and siliques, and possess serrated leaves. These defects are possibly due to altered small RNA stability or activity. Additionally, thenrpc7-1mutation confers anNLR-specific alternative splicing defect that correlates with enhanced disease resistance, highlighting the importance of alternative splicing in regulating NLR activity. Altogether, these results reveal novel roles for Pol III in maintaining RNA homeostasis, adjusting the expression of a diverse suite of genes, and indirectly modulating gene splicing. Future analyses using thenrpc7-1mutant will be instrumental in examining other unknown Pol III functions. PMID:26865731

  11. Arabidopsis lectin receptor kinases LecRK-IX.1 and LecRK-IX.2 are functional analogs in regulating phytophthora resistance and plant cell death

    NARCIS (Netherlands)

    Wang, Yan; Cordewener, Jan H G; America, Antoine H P; Shan, Weixing; Bouwmeester, Klaas; Govers, Francine

    2015-01-01

    L-type lectin receptor kinases (LecRK) are potential immune receptors. Here, we characterized two closely-related Arabidopsis LecRK, LecRK-IX.1 and LecRK-IX.2, of which T-DNA insertion mutants showed compromised resistance to Phytophthora brassicae and Phytophthora capsici, with double mutants showi

  12. Functional analysis of water stress-responsive soybean GmNAC003 and GmNAC004 transcription factors in lateral root development in arabidopsis.

    Directory of Open Access Journals (Sweden)

    Truyen N Quach

    Full Text Available In Arabidopsis, NAC (NAM, ATAF and CUC transcription factors have been found to promote lateral root number through the auxin signaling pathway. In the present study, the role of water stress-inducible soybean GmNAC003 and GmNAC004 genes in the enhancement of lateral root development under water deficit conditions was investigated. Both genes were highly expressed in roots, leaves and flowers of soybean and were strongly induced by water stress and moderately induced by a treatment with abscisic acid (ABA. They showed a slight response to treatment with 2,4-dichlorophenoxyacetic acid (2,4-D. The transgenic Arabidopsis plants overexpressing GmNAC004 showed an increase in lateral root number and length under non-stress conditions and maintained higher lateral root number and length under mild water stress conditions compared to the wild-type (WT, while the transgenic plants overexpressing GmNAC003 did not show any response. However, LR development of GmNAC004 transgenic Arabidopsis plants was not enhanced in the water-stressed compared to the well-watered treatment. In the treatment with ABA, LR density of the GmNAC004 transgenic Arabidopsis was less suppressed than that of the WT, suggesting that GmNAC004 counteracts ABA-induced inhibition of lateral root development. In the treatment with 2,4-D, lateral root density was enhanced in both GmNAC004 transgenic Arabidopsis and WT plants but the promotion was higher in the transgenic plants. Conversely, in the treatment with naphthylphthalamic acid (NPA, lateral root density was inhibited and there was no difference in the phenotype of the GmNAC004 transgenic Arabidopsis and WT plants, indicating that auxin is required for the action of GmNAC004. Transcript analysis for a number of known auxin and ABA related genes showed that GmNAC004's role may suppress ABA signaling but promote auxin signaling to increase lateral root development in the Arabidopsis heterologous system.

  13. Phosphatidic Acid Interacts with a MYB Transcription Factor and Regulates Its Nuclear Localization and Function in Arabidopsis[C][W

    Science.gov (United States)

    Yao, Hongyan; Wang, Geliang; Guo, Liang; Wang, Xuemin

    2013-01-01

    Phosphatidic acid (PA) has emerged as a class of cellular mediators involved in various cellular and physiological processes, but little is known about its mechanism of action. Here we show that PA interacts with WEREWOLF (WER), a R2R3 MYB transcription factor involved in root hair formation. The PA-interacting region is confined to the end of the R2 subdomain. The ablation of the PA binding motif has no effect on WER binding to DNA, but abolishes its nuclear localization and its function in regulating epidermal cell fate. Inhibition of PA production by phospholipase Dζ also suppresses WER’s nuclear localization, root hair formation, and elongation. These results suggest a role for PA in promoting protein nuclear localization. PMID:24368785

  14. Phosphatidic acid interacts with a MYB transcription factor and regulates its nuclear localization and function in Arabidopsis.

    Science.gov (United States)

    Yao, Hongyan; Wang, Geliang; Guo, Liang; Wang, Xuemin

    2013-12-01

    Phosphatidic acid (PA) has emerged as a class of cellular mediators involved in various cellular and physiological processes, but little is known about its mechanism of action. Here we show that PA interacts with werewolf (WER), a R2R3 MYB transcription factor involved in root hair formation. The PA-interacting region is confined to the end of the R2 subdomain. The ablation of the PA binding motif has no effect on WER binding to DNA, but abolishes its nuclear localization and its function in regulating epidermal cell fate. Inhibition of PA production by phospholipase Dζ also suppresses WER's nuclear localization, root hair formation, and elongation. These results suggest a role for PA in promoting protein nuclear localization.

  15. Alternative splicing of Arabidopsis IBR5 pre-mRNA generates two IBR5 isoforms with distinct and overlapping functions.

    Directory of Open Access Journals (Sweden)

    Thilanka Jayaweera

    Full Text Available The INDOLE-3-BUTYRIC ACID RESPONSE5 (IBR5 gene encodes a dual specificity phosphatase that regulates plant auxin responses. IBR5 has been predicted to generate two transcripts through alternative splicing, but alternative splicing of IBR5 has not been confirmed experimentally. The previously characterized ibr5-1 null mutant exhibits many auxin related defects such as auxin insensitive primary root growth, defective vascular development, short stature and reduced lateral root development. However, whether all these defects are caused by the lack of phosphatase activity is not clear. Here we describe two new auxin insensitive IBR5 alleles, ibr5-4, a catalytic site mutant, and ibr5-5, a splice site mutant. Characterization of these new mutants indicates that IBR5 is post-transcriptionally regulated to generate two transcripts, AT2G04550.1 and AT2G04550.3, and consequently two IBR5 isoforms, IBR5.1 and IBR5.3. The IBR5.1 isoform exhibits phosphatase catalytic activity that is required for both proper degradation of Aux/IAA proteins and auxin-induced gene expression. These two processes are independently regulated by IBR5.1. Comparison of new mutant alleles with ibr5-1 indicates that all three mutant alleles share many phenotypes. However, each allele also confers distinct defects implicating IBR5 isoform specific functions. Some of these functions are independent of IBR5.1 catalytic activity. Additionally, analysis of these new mutant alleles suggests that IBR5 may link ABP1 and SCF(TIR1/AFBs auxin signaling pathways.

  16. 煤焦沥青烟提取物致BEAS-2B恶性转化细胞中姊妹染色单体分离相关蛋白的改变%Change of structurol maintenance of chromosome(SMC )1, SMC3, separase and securin expression in BEAS-2B malignant transformation cell induced by coal tar pitch smoke extracts

    Institute of Scientific and Technical Information of China (English)

    李智涛; 王威; 赵勇; 王丽霞; 祝寒松; 吴卫东; 吴逸明

    2010-01-01

    目的 通过检测姊妹染色体凝集和分离相关蛋白染色体结构维持蛋白(SMC)1、SMC3、分离酶(Separase)和保全素(Securin)在煤焦沥青致BEAS-2B癌变细胞中的变化,探讨其在煤焦沥青接触者肺癌发生中的作用.方法 用中温煤焦沥青烟提取物作为诱导剂,建立永生化人支气管上皮细胞BEAS-2B的恶性转化模型,用实时定量反转录-聚合酶链反应(RT-PCR)检测相关基因的mRNA表达水平;细胞爬片免疫组化半定量法检测其蛋白表达改变.以二甲亚砜(DMSO)溶剂组和未染毒的正常传代的BEAS-2B细胞为对照组.结果 与正常对照组和DMSO溶剂对照组比较,煤焦沥青烟提取物诱导转化细胞中,SMC1基因和蛋白表达水平的差异无统计学意义(P>0.05);煤焦沥青烟诱导组SMC3和Separase的基因和蛋白表达水平明显升高(基因:SMC3:2.54±0.20、Separase:2.42±0.22,蛋白:SMC3:0.27±0.02、Separase:0.25±0.02),Securin的基因和蛋白表达水平明显降低(基因:0.30±0.04,蛋白:0.17±0.01),与其他两组(DMSO溶剂对照组:基因:SMC3:1.13±0.12、Separase:1.00±0.04、Securin:0.90±0.11,蛋白:SMC3:0.10±0.03、Separase:0.18±0.02、Securin:0.22±0.02;正常对照组:基因:SMC3:1.00±0.11、Separase:1.00±0.08、Securin:1.00±0.11,蛋白:SMC3:0.09±0.01、Separase:0.18±0.01、Securin:0.23±0.02)相比,差异均有统计学意义(P<0.05).结论 在煤焦沥青致支气管上皮细胞恶性转化过程中,姊妹染色单体凝集和分离相关蛋白SMC3和Separase升高,Securin表达水平降低,参与了细胞恶性转化过程.%Objective To study the role of structural maintenance of chromosome (SMC)1, SMC3,Separase and Securin in tumorgenesis that contact with coal tar pitch. Methods The BEAS-2B cells was induced by coal tar pitch smoke extracts to form malignant transformation cell model in vitro. The gene expression levels of mRNA were assessed by real-time quantitative RT-PCR, and the protein expression variation

  17. Major latex protein-like protein 43 (MLP43) functions as a positive regulator during abscisic acid responses and confers drought tolerance in Arabidopsis thaliana

    OpenAIRE

    WANG, YANPING; Yang, Li; Chen, Xi; Ye, Tiantian; Zhong, Bao; Liu, Ruijie; Wu, Yan; Chan, Zhulong

    2015-01-01

    Drought stress is one of the disadvantageous environmental conditions for plant growth and reproduction. Given the importance of abscisic acid (ABA) to plant growth and abiotic stress responses, identification of novel components involved in ABA signalling transduction is critical. In this study, we screened numerous Arabidopsis thaliana mutants by seed germination assay and identified a mutant mlp43 (major latex protein-like 43) with decreased ABA sensitivity in seed germination. The mlp43 m...

  18. Insights into the Structural and Functional Evolution of Plant Genomes Afforded by the Nucleotide Sequences of Chromosomes 2 and 4 of Arabidopsis thaliana

    OpenAIRE

    Bancroft, Ian

    2000-01-01

    The rapidly accumulating genome sequence data from the plant Arabidopsis thaliana allows more detailed analysis of genome content and organisation than ever bafore possible in plants. The genome shows a surprisingly high level of genetic redundancy, with as many as 75% of gene products showing signficant homology to another protien of A. thaliana. Many duplicated genes occur in arrays of conserved order and indicate that A. thaliana is likely to have had a tetraploid ancestor. Analysis of the...

  19. Insights Into the Structural and Functional Evolution of Plant Genomes Afforded by the Nucleotide Sequences of Chromosomes 2 and 4 of Arabidopsis Thaliana

    OpenAIRE

    Bancroft, Ian

    2000-01-01

    The rapidly accumulating genome sequence data from the plant Arabidopsis thaliana allows more detailed analysis of genome content and organisation than ever bafore possible in plants. The genome shows a surprisingly high level of genetic redundancy, with as many as 75% of gene products showing signficant homology to another protien of A. thaliana. Many duplicated genes occur in arrays of conserved order and indicate that A. thaliana is likely to have had a tetraploid ancestor. Analysis of the...

  20. Gibberellins control fruit patterning in Arabidopsis thaliana.

    Science.gov (United States)

    Arnaud, Nicolas; Girin, Thomas; Sorefan, Karim; Fuentes, Sara; Wood, Thomas A; Lawrenson, Tom; Sablowski, Robert; Østergaard, Lars

    2010-10-01

    The Arabidopsis basic helix-loop-helix (bHLH) proteins INDEHISCENT (IND) and ALCATRAZ (ALC) specify tissues required for fruit opening that have major roles in seed dispersal and plant domestication. Here, we show that synthesis of the phytohormone gibberellin is a direct and necessary target of IND, and that ALC interacts directly with DELLA repressors, which antagonize ALC function but are destabilized by gibberellin. Thus, the gibberellin/DELLA pathway has a key role in patterning the Arabidopsis fruit, and the interaction between DELLA and bHLH proteins, previously shown to connect gibberellin and light responses, is a versatile regulatory module also used in tissue patterning. PMID:20889713

  1. Arabidopsis CALCIUM-DEPENDENT PROTEIN KINASE8 and CATALASE3 Function in Abscisic Acid-Mediated Signaling and H2O2 Homeostasis in Stomatal Guard Cells under Drought Stress.

    Science.gov (United States)

    Zou, Jun-Jie; Li, Xi-Dong; Ratnasekera, Disna; Wang, Cun; Liu, Wen-Xin; Song, Lian-Fen; Zhang, Wen-Zheng; Wu, Wei-Hua

    2015-05-01

    Drought is a major threat to plant growth and crop productivity. Calcium-dependent protein kinases (CDPKs, CPKs) are believed to play important roles in plant responses to drought stress. Here, we report that Arabidopsis thaliana CPK8 functions in abscisic acid (ABA)- and Ca(2+)-mediated plant responses to drought stress. The cpk8 mutant was more sensitive to drought stress than wild-type plants, while the transgenic plants overexpressing CPK8 showed enhanced tolerance to drought stress compared with wild-type plants. ABA-, H2O2-, and Ca(2+)-induced stomatal closing were impaired in cpk8 mutants. Arabidopsis CATALASE3 (CAT3) was identified as a CPK8-interacting protein, confirmed by yeast two-hybrid, coimmunoprecipitation, and bimolecular fluorescence complementation assays. CPK8 can phosphorylate CAT3 at Ser-261 and regulate its activity. Both cpk8 and cat3 plants showed lower catalase activity and higher accumulation of H2O2 compared with wild-type plants. The cat3 mutant displayed a similar drought stress-sensitive phenotype as cpk8 mutant. Moreover, ABA and Ca(2+) inhibition of inward K(+) currents were diminished in guard cells of cpk8 and cat3 mutants. Together, these results demonstrated that CPK8 functions in ABA-mediated stomatal regulation in responses to drought stress through regulation of CAT3 activity. PMID:25966761

  2. Histone H1 Variants in Arabidopsis Are Subject to Numerous Post-Translational Modifications, Both Conserved and Previously Unknown in Histones, Suggesting Complex Functions of H1 in Plants.

    Science.gov (United States)

    Kotliński, Maciej; Rutowicz, Kinga; Kniżewski, Łukasz; Palusiński, Antoni; Olędzki, Jacek; Fogtman, Anna; Rubel, Tymon; Koblowska, Marta; Dadlez, Michał; Ginalski, Krzysztof; Jerzmanowski, Andrzej

    2016-01-01

    Linker histones (H1s) are conserved and ubiquitous structural components of eukaryotic chromatin. Multiple non-allelic variants of H1, which differ in their DNA/nucleosome binding properties, co-exist in animal and plant cells and have been implicated in the control of genetic programs during development and differentiation. Studies in mammals and Drosophila have revealed diverse post-translational modifications of H1s, most of which are of unknown function. So far, it is not known how this pattern compares with that of H1s from other major lineages of multicellular Eukaryotes. Here, we show that the two main H1variants of a model flowering plant Arabidopsis thaliana are subject to a rich and diverse array of post-translational modifications. The distribution of these modifications in the H1 molecule, especially in its globular domain (GH1), resembles that occurring in mammalian H1s, suggesting that their functional significance is likely to be conserved. While the majority of modifications detected in Arabidopsis H1s, including phosphorylation, acetylation, mono- and dimethylation, formylation, crotonylation and propionylation, have also been reported in H1s of other species, some others have not been previously identified in histones.

  3. An Atlas of Type I MADS Box Gene Expression during Female Gametophyte and Seed Development in Arabidopsis[W].

    NARCIS (Netherlands)

    Bemer, M.; Heijmans, K.; Airoldi, C.A.; Davies, B.; Angenent, G.C.

    2010-01-01

    Members of the plant type I MADS domain subfamily have been reported to be involved in reproductive development in Arabidopsis (Arabidopsis thaliana). However, from the 61 type I genes in the Arabidopsis genome, only PHERES1, AGAMOUS-LIKE80 (AGL80), DIANA, AGL62, and AGL23 have been functionally cha

  4. Cloning and Function Characteristic of GhDWF 4,an Ortholog of Arabidopsis DWF 4 from Upland Cotton (Gossypium hirsutum L.)

    Institute of Scientific and Technical Information of China (English)

    HU Ming-yu; LUO Ming; TAN Kun-ling; XIAO Zhong-yi; PEI Yan

    2008-01-01

    @@ As one of the longest cells characterized in plant kingdom,cotton fibers were regarded as an ideal material for studying plant cell growth and development.In recent years,several reports revealed that brassinosteroids (BRs) play an important role in the growth and development of cotton fiber.To further investigate the effect of BRs on fiber cell development and illuminate the mechanism of BRs action,we cloned GhDWF4,an ortholog of Arabidopsis DWF4 from upland cotton (Gossypium hirsuturn L.).

  5. AtNOS/AtNOA1 Is a Functional Arabidopsis thaliana cGTPase and Not a Nitric-oxide Synthase*S⃞

    OpenAIRE

    Moreau, Magali; Lee, Gyu In; Wang, Yongzeng; Crane, Brian R.; Klessig, Daniel F

    2008-01-01

    AtNOS1 was previously identified as a potential nitric-oxide synthase (NOS) in Arabidopsis thaliana, despite lack of sequence similarity to animal NOSs. Although the dwarf and yellowish leaf phenotype of Atnos1 knock-out mutant plants can be rescued by treatment with exogenous NO, doubts have recently been raised as to whether AtNOS1 is a true NOS. Moreover, depending on the type of physiological responses studied, Atnos1 is not always deficient in NO induction and/or ...

  6. Arabidopsis AtRRP44A is the functional homolog of Rrp44/Dis3, an exosome component, is essential for viability and is required for RNA processing and degradation.

    Directory of Open Access Journals (Sweden)

    Naoyoshi Kumakura

    Full Text Available The RNA exosome is a multi-subunit complex that is responsible for 3' to 5' degradation and processing of cellular RNA. Rrp44/Dis3 is the catalytic center of the exosome in yeast and humans. However, the role of Rrp44/Dis3 homologs in plants is still unidentified. Here, we show that Arabidopsis AtRRP44A is the functional homolog of Rrp44/Dis3, is essential for plant viability and is required for RNA processing and degradation. We characterized AtRRP44A and AtRRP44B/SOV, two predicted Arabidopsis Rrp44/Dis3 homologs. AtRRP44A could functionally replace S. cerevisiae Rrp44/Dis3, but AtRRP44B/SOV could not. rrp44a knock-down mutants showed typical phenotypes of exosome function deficiency, 5.8S rRNA 3' extension and rRNA maturation by-product over-accumulation, but rrp44b mutants did not. Conversely, AtRRP44B/SOV mutants showed elevated levels of a selected mRNA, on which rrp44a did not have detectable effects. Although T-DNA insertion mutants of AtRRP44B/SOV had no obvious phenotype, those of AtRRP44A showed defects in female gametophyte development and early embryogenesis. These results indicate that AtRRP44A and AtRRP44B/SOV have independent roles for RNA turnover in plants.

  7. Polyploidy in the Arabidopsis genus.

    Science.gov (United States)

    Bomblies, Kirsten; Madlung, Andreas

    2014-06-01

    Whole genome duplication (WGD), which gives rise to polyploids, is a unique type of mutation that duplicates all the genetic material in a genome. WGD provides an evolutionary opportunity by generating abundant genetic "raw material," and has been implicated in diversification, speciation, adaptive radiation, and invasiveness, and has also played an important role in crop breeding. However, WGD at least initially challenges basic biological functions by increasing cell size, altering relationships between cell volume and DNA content, and doubling the number of homologous chromosome copies that must be sorted during cell division. Newly polyploid lineages often have extensive changes in gene regulation, genome structure, and may suffer meiotic or mitotic chromosome mis-segregation. The abundance of species that persist in nature as polyploids shows that these problems are surmountable and/or that advantages of WGD might outweigh drawbacks. The molecularly especially tractable Arabidopsis genus has several ancient polyploidy events in its history and contains several independent more recent polyploids. This genus can thus provide important insights into molecular aspects of polyploid formation, establishment, and genome evolution. The ability to integrate ecological and evolutionary questions with molecular and genetic understanding makes comparative analyses in this genus particularly attractive and holds promise for advancing our general understanding of polyploid biology. Here, we highlight some of the findings from Arabidopsis that have given us insights into the origin and evolution of polyploids. PMID:24788061

  8. Suppressor Screens in Arabidopsis.

    Science.gov (United States)

    Li, Xin; Zhang, Yuelin

    2016-01-01

    Genetic screens have proven to be a useful tool in the dissection of biological processes in plants. Specifically, suppressor screens have been widely used to study signal transduction pathways. Here we provide a detailed protocol for ethyl methanesulfonate (EMS) mutagenesis used in our suppressor screens in Arabidopsis and discuss the basic principles behind suppressor screen design and downstream analyses. PMID:26577776

  9. Expression of Caenorhabditis elegans PCS in the AtPCS1-deficient Arabidopsis thaliana cad1-3 mutant separates the metal tolerance and non-host resistance functions of phytochelatin synthases.

    Science.gov (United States)

    Kühnlenz, Tanja; Westphal, Lore; Schmidt, Holger; Scheel, Dierk; Clemens, Stephan

    2015-11-01

    Phytochelatin synthases (PCS) play key roles in plant metal tolerance. They synthesize small metal-binding peptides, phytochelatins, under conditions of metal excess. Respective mutants are strongly cadmium and arsenic hypersensitive. However, their ubiquitous presence and constitutive expression had long suggested a more general function of PCS besides metal detoxification. Indeed, phytochelatin synthase1 from Arabidopsis thaliana (AtPCS1) was later implicated in non-host resistance. The two different physiological functions may be attributable to the two distinct catalytic activities demonstrated for AtPCS1, that is the dipeptidyl transfer onto an acceptor molecule in phytochelatin synthesis, and the proteolytic deglycylation of glutathione conjugates. In order to test this hypothesis and to possibly separate the two biological roles, we expressed a phylogenetically distant PCS from Caenorhabditis elegans in an AtPCS1 mutant. We confirmed the involvement of AtPCS1 in non-host resistance by showing that plants lacking the functional gene develop a strong cell death phenotype when inoculated with the potato pathogen Phytophthora infestans. Furthermore, we found that the C. elegans gene rescues phytochelatin synthesis and cadmium tolerance, but not the defect in non-host resistance. This strongly suggests that the second enzymatic function of AtPCS1, which remains to be defined in detail, is underlying the plant immunity function.

  10. Analyzing Synthetic Promoters Using Arabidopsis Protoplasts.

    Science.gov (United States)

    Stracke, Ralf; Thiedig, Katharina; Kuhlmann, Melanie; Weisshaar, Bernd

    2016-01-01

    This chapter describes a transient protoplast co-transfection method that can be used to quantitatively study in vivo the activity and function of promoters and promoter elements (reporters), and their induction or repression by transcription factors (effectors), stresses, hormones, or metabolites. A detailed protocol for carrying out transient co-transfection assays with Arabidopsis At7 protoplasts and calculating the promoter activity is provided. PMID:27557761

  11. Single Molecule Analysis of the Arabidopsis FRA1 Kinesin Shows that It Is a Functional Motor Protein with Unusually High Processivity

    Institute of Scientific and Technical Information of China (English)

    Chuanmei Zhu; Ram Dixit

    2011-01-01

    The Arabidopsis FRA1 kinesin contributes to the organization of cellulose microfibrils through an unknown mechanism.The cortical localization of this kinesin during interphase raises the possibility that it transports cell wallrelated cargoes along cortical microtubules that either directly or indirectly influence cellulose microfibril patterning.To determine whether FRA1 is an authentic motor protein,we combined bulk biochemical assays and single molecule fluorescence imaging to analyze the motor properties of recombinant,GFP-tagged FRA1 containing the motor and coiled-coil domains (designated as FRA1(707)-GFP).We found that FRA1(707)-GFP binds to microtubules in an ATP-dependent manner and that its ATPase activity is dramatically stimulated by the presence of microtubules.Using single molecule studies,we found that FRA1(707)-GFP moves processively along microtubule tracks at a velocity of about 0.4 μm s-1.In addition,we found that FRA1(707)-GFP is a microtubule plus-end-directed motor and that it moves along microtubules as a dimer.Interestingly,our single molecule analysis shows that the processivity of FRA1(707)-GFP is at least twice the processivity of conventional kinesin,making FRA1 the most processive kinesin to date.Together,our data show that FRA1 is a bona fide motor protein that has the potential to drive long-distance transport of cargo along cortical microtubules.

  12. MYB97, MYB101 and MYB120 function as male factors that control pollen tube-synergid interaction in Arabidopsis thaliana fertilization.

    Directory of Open Access Journals (Sweden)

    Yan Liang

    2013-11-01

    Full Text Available Pollen tube reception involves a pollen tube-synergid interaction that controls the discharge of sperm cells into the embryo sac during plant fertilization. Despite its importance in the sexual reproduction of plants, little is known about the role of gene regulation in this process. We report here that the pollen-expressed transcription factors MYB97, MYB101 and MYB120 probably control genes whose encoded proteins play important roles in Arabidopsis thaliana pollen tube reception. They share a high amino acid sequence identity and are expressed mainly in mature pollen grains and pollen tubes. None of the single or double mutants of these three genes exhibited any visible defective phenotype. Although the myb97 myb101 myb120 triple mutant was not defective in pollen development, pollen germination, pollen tube growth or tube guidance, the pollen tubes of the triple mutants exhibited uncontrolled growth and failed to discharge their sperm cells after entering the embryo sac. In addition, the myb97 myb101 myb120 triple mutation significantly affected the expression of a group of pollen-expressed genes in mature pollen grains. All these results indicate that MYB97, MYB101 and MYB120 participate in pollen tube reception, possibly by controlling the expression of downstream genes.

  13. Arabidopsis in Wageningen

    OpenAIRE

    Koornneef, M

    2013-01-01

    Arabidopsis thaliana is the plant species that in the past 25 years has developed into the major model species in plant biology research. This was due to its properties such as short generation time, its small genome and its easiness to be transformed. Wageningen University has played an important role in the development of this model, based on interdisciplinary collaborations using genetics as a major tool to investigate aspects of physiology, development, plant-microbe interactions and evol...

  14. Identification of proteins interacting with Arabidopsis ACD11

    DEFF Research Database (Denmark)

    Petersen, Nikolaj H T; Joensen, Jan; McKinney, Lea V;

    2009-01-01

    The Arabidopsis ACD11 gene encodes a sphingosine transfer protein and was identified by the accelerated cell death phenotype of the loss of function acd11 mutant, which exhibits heightened expression of genes involved in the disease resistance hypersensitive response (HR). We used ACD11 as bait...... in a yeast two-hybrid screen of an Arabidopsis cDNA library to identify ACD11 interacting proteins. One interactor identified is a protein of unknown function with an RNA recognition motif (RRM) designated BPA1 (binding partner of ACD11). Co-immunoprecipitation experiments confirmed the ACD11-BPA1...

  15. Computational analyses and annotations of the Arabidopsis peroxidasegene family

    DEFF Research Database (Denmark)

    Østergaard, Lars; Pedersen, Anders Gorm; Jespersen, Hans M.;

    1998-01-01

    Classical heme-containing plant peroxidases have been ascribed a wide variety of functional roles related to development, defense, lignification and hormonal signaling. More than 40 peroxidase genes are now known in Arabidopsis thaliana for which functional association is complicated by a general...... lack of peroxidase substrate specificity. Computational analysis was performed on 30 near full-length Arabidopsis peroxidase cDNAs for annotation of start codons and signal peptide cleavage sites. A compositional analysis revealed that 23 of the 30 peroxidase cDNAs have 5' untranslated regions...

  16. The arabidopsis cyclic nucleotide interactome

    KAUST Repository

    Donaldson, Lara

    2016-05-11

    Background Cyclic nucleotides have been shown to play important signaling roles in many physiological processes in plants including photosynthesis and defence. Despite this, little is known about cyclic nucleotide-dependent signaling mechanisms in plants since the downstream target proteins remain unknown. This is largely due to the fact that bioinformatics searches fail to identify plant homologs of protein kinases and phosphodiesterases that are the main targets of cyclic nucleotides in animals. Methods An affinity purification technique was used to identify cyclic nucleotide binding proteins in Arabidopsis thaliana. The identified proteins were subjected to a computational analysis that included a sequence, transcriptional co-expression and functional annotation analysis in order to assess their potential role in plant cyclic nucleotide signaling. Results A total of twelve cyclic nucleotide binding proteins were identified experimentally including key enzymes in the Calvin cycle and photorespiration pathway. Importantly, eight of the twelve proteins were shown to contain putative cyclic nucleotide binding domains. Moreover, the identified proteins are post-translationally modified by nitric oxide, transcriptionally co-expressed and annotated to function in hydrogen peroxide signaling and the defence response. The activity of one of these proteins, GLYGOLATE OXIDASE 1, a photorespiratory enzyme that produces hydrogen peroxide in response to Pseudomonas, was shown to be repressed by a combination of cGMP and nitric oxide treatment. Conclusions We propose that the identified proteins function together as points of cross-talk between cyclic nucleotide, nitric oxide and reactive oxygen species signaling during the defence response.

  17. An Arabidopsis callose synthase

    DEFF Research Database (Denmark)

    Ostergaard, Lars; Petersen, Morten; Mattsson, Ole;

    2002-01-01

    in the Arabidopsis mpk4 mutant which exhibits systemic acquired resistance (SAR), elevated beta-1,3-glucan synthase activity, and increased callose levels. In addition, AtGsl5 is a likely target of salicylic acid (SA)-dependent SAR, since AtGsl5 mRNA accumulation is induced by SA in wild-type plants, while...... expression of the nahG salicylate hydroxylase reduces AtGsl5 mRNA levels in the mpk4 mutant. These results indicate that AtGsl5 is likely involved in callose synthesis in flowering tissues and in the mpk4 mutant....

  18. 拟南芥亚硫酸盐氧化酶基因AtSO启动子的分离与功能分析%Isolation and Functional Analysis of Sulfite Oxidase Gene AtSO Promoter from Arabidopsis thaliana

    Institute of Scientific and Technical Information of China (English)

    夏宗良; 王美平; 刘全军

    2007-01-01

    亚硫酸盐氧化酶(SO)作为目前发现的钼酶家族成员之一,在哺乳动物硫化物的脱毒、嘌呤代谢等过程中起着非常重要的作用.然而,很少有关于高等植物SO的表达和调控机制的研究报道.本研究中,我们用半定量RT-PCR和组织化学方法对拟南芥中SO基因AtSO的表达调控进行了初步研究.结果表明,AtSO在拟南芥的地上部分如茎、叶、花和未成熟荚果中有较高的表达水平,而在根部表达水平较低.在对分离的该基因上游1 562-bp的启动子区域进行生物信息学分析时,鉴定出一些可能的调控元件如光调控元件(LRE).转基因植株中AtSO启动子驱动下的GUS基因(uidA)表达结果表明:AtSO的表达主要在植物的地上组织,表达具有光依赖性,且表达水平受亚硫酸盐的诱导增高.这一结果对进一步研究SO在植物对光周期和亚硫酸盐胁迫应答反应中的作用提供线索.%Sulfite oxidase(SO),one of the known molybdenum co-factor-containing enzymes,plays important roles in diverse metabolic processes such as sulfur detoxification and purine catabolism in mammals.But much less is known about the expression and regulatory characterization of sulfite oxidase gene in higher plants.In this report.expression of Arabidopsis SO is characterized in detail by semi-quantitative RT-PCR and histochemical staining.The results showed that the transcripts of AtSO were predominantly detected in Arabidopsis aerial tissues including stems,young leaves,young inflorescences and immature siliques at higher level.but in roots with a lower level.To monitor AtSO expression in plant,the promoter region containing a 1 562-bp genomic sequence from AtSO was isolated and analyzed using methods of bioinformatics.Basing on the distribution of beta-glucuronidase(GUS)activities shown by histochemical staining in transgenic Arabidopsis plants harboring the promoter-uidA fusion construct,it can be concluded that AtSO is expressed mainly in

  19. MASSUGU2 encodes Aux/IAA19, an auxin-regulated protein that functions together with the transcriptional activator NPH4/ARF7 to regulate differential growth responses of hypocotyl and formation of lateral roots in Arabidopsis thaliana.

    Science.gov (United States)

    Tatematsu, Kiyoshi; Kumagai, Satoshi; Muto, Hideki; Sato, Atsuko; Watahiki, Masaaki K; Harper, Reneé M; Liscum, Emmanuel; Yamamoto, Kotaro T

    2004-02-01

    We have isolated a dominant, auxin-insensitive mutant of Arabidopsis thaliana, massugu2 (msg2), that displays neither hypocotyl gravitropism nor phototropism, fails to maintain an apical hook as an etiolated seedling, and is defective in lateral root formation. Yet other aspects of growth and development of msg2 plants are almost normal. These characteristics of msg2 are similar to those of another auxin-insensitive mutant, non-phototropic hypocotyl4 (nph4), which is a loss-of-function mutant of AUXIN RESPONSE FACTOR7 (ARF7) (Harper et al., 2000). Map-based cloning of the MSG2 locus reveals that all four mutant alleles result in amino acid substitutions in the conserved domain II of an Auxin/Indole-3-Acetic Acid protein, IAA19. Interestingly, auxin inducibility of MSG2/IAA19 gene expression is reduced by 65% in nph4/arf7. Moreover, MSG2/IAA19 protein binds to the C-terminal domain of NPH4/ARF7 in a Saccharomyces cerevisiae (yeast) two-hybrid assay and to the whole latter protein in vitro by pull-down assay. These results suggest that MSG2/IAA19 and NPH4/ARF7 may constitute a negative feedback loop to regulate differential growth responses of hypocotyls and lateral root formation.

  20. Characterization of multiple SPS knockout mutants reveals redundant functions of the four Arabidopsis sucrose phosphate synthase isoforms in plant viability, and strongly indicates that enhanced respiration and accelerated starch turnover can alleviate the blockage of sucrose biosynthesis.

    Science.gov (United States)

    Bahaji, Abdellatif; Baroja-Fernández, Edurne; Ricarte-Bermejo, Adriana; Sánchez-López, Ángela María; Muñoz, Francisco José; Romero, Jose M; Ruiz, María Teresa; Baslam, Marouane; Almagro, Goizeder; Sesma, María Teresa; Pozueta-Romero, Javier

    2015-09-01

    We characterized multiple knock-out mutants of the four Arabidopsis sucrose phosphate synthase (SPSA1, SPSA2, SPSB and SPSC) isoforms. Despite their reduced SPS activity, spsa1/spsa2, spsa1/spsb, spsa2/spsb, spsa2/spsc, spsb/spsc, spsa1/spsa2/spsb and spsa2/spsb/spsc mutants displayed wild type (WT) vegetative and reproductive morphology, and showed WT photosynthetic capacity and respiration. In contrast, growth of rosettes, flowers and siliques of the spsa1/spsc and spsa1/spsa2/spsc mutants was reduced compared with WT plants. Furthermore, these plants displayed a high dark respiration phenotype. spsa1/spsb/spsc and spsa1/spsa2/spsb/spsc seeds poorly germinated and produced aberrant and sterile plants. Leaves of all viable sps mutants, except spsa1/spsc and spsa1/spsa2/spsc, accumulated WT levels of nonstructural carbohydrates. spsa1/spsc leaves possessed high levels of metabolic intermediates and activities of enzymes of the glycolytic and tricarboxylic acid cycle pathways, and accumulated high levels of metabolic intermediates of the nocturnal starch-to-sucrose conversion process, even under continuous light conditions. Results presented in this work show that SPS is essential for plant viability, reveal redundant functions of the four SPS isoforms in processes that are important for plant growth and nonstructural carbohydrate metabolism, and strongly indicate that accelerated starch turnover and enhanced respiration can alleviate the blockage of sucrose biosynthesis in spsa1/spsc leaves.

  1. Functional conservation and divergence of four ginger AP1/AGL9 MADS-box genes revealed by analysis of their expression and protein-protein interaction, and ectopic expression of AhFUL gene in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Xiumei Li

    Full Text Available Alpinia genus are known generally as ginger-lilies for showy flowers in the ginger family, Zingiberaceae, and their floral morphology diverges from typical monocotyledon flowers. However, little is known about the functions of ginger MADS-box genes in floral identity. In this study, four AP1/AGL9 MADS-box genes were cloned from Alpinia hainanensis, and protein-protein interactions (PPIs and roles of the four genes in floral homeotic conversion and in floral evolution are surveyed for the first time. AhFUL is clustered to the AP1 lineage, AhSEP4 and AhSEP3b to the SEP lineage, and AhAGL6-like to the AGL6 lineage. The four genes showed conserved and divergent expression patterns, and their encoded proteins were localized in the nucleus. Seven combinations of PPI (AhFUL-AhSEP4, AhFUL-AhAGL6-like, AhFUL-AhSEP3b, AhSEP4-AhAGL6-like, AhSEP4-AhSEP3b, AhAGL6-like-AhSEP3b, and AhSEP3b-AhSEP3b were detected, and the PPI patterns in the AP1/AGL9 lineage revealed that five of the 10 possible combinations are conserved and three are variable, while conclusions cannot yet be made regarding the other two. Ectopic expression of AhFUL in Arabidopsis thaliana led to early flowering and floral organ homeotic conversion to sepal-like or leaf-like. Therefore, we conclude that the four A. hainanensis AP1/AGL9 genes show functional conservation and divergence in the floral identity from other MADS-box genes.

  2. Metabolomic Characterization of Knockout Mutants in Arabidopsis: Development of a Metabolite Profiling Database for Knockout Mutants in Arabidopsis.

    Science.gov (United States)

    Fukushima, Atsushi; Kusano, Miyako; Mejia, Ramon Francisco; Iwasa, Mami; Kobayashi, Makoto; Hayashi, Naomi; Watanabe-Takahashi, Akiko; Narisawa, Tomoko; Tohge, Takayuki; Hur, Manhoi; Wurtele, Eve Syrkin; Nikolau, Basil J; Saito, Kazuki

    2014-05-14

    Despite recent intensive research efforts in functional genomics, the functions of only a limited number of Arabidopsis (Arabidopsis thaliana) genes have been determined experimentally, and improving gene annotation remains a major challenge in plant science. As metabolite profiling can characterize the metabolomic phenotype of a genetic perturbation in the plant metabolism, it provides clues to the function(s) of genes of interest. We chose 50 Arabidopsis mutants, including a set of characterized and uncharacterized mutants, that resemble wild-type plants. We performed metabolite profiling of the plants using gas chromatography-mass spectrometry. To make the data set available as an efficient public functional genomics tool for hypothesis generation, we developed the Metabolite Profiling Database for Knock-Out Mutants in Arabidopsis (MeKO). It allows the evaluation of whether a mutation affects metabolism during normal plant growth and contains images of mutants, data on differences in metabolite accumulation, and interactive analysis tools. Nonprocessed data, including chromatograms, mass spectra, and experimental metadata, follow the guidelines set by the Metabolomics Standards Initiative and are freely downloadable. Proof-of-concept analysis suggests that MeKO is highly useful for the generation of hypotheses for genes of interest and for improving gene annotation. MeKO is publicly available at http://prime.psc.riken.jp/meko/.

  3. Transgenic Arabidopsis Gene Expression System

    Science.gov (United States)

    Ferl, Robert; Paul, Anna-Lisa

    2009-01-01

    The Transgenic Arabidopsis Gene Expression System (TAGES) investigation is one in a pair of investigations that use the Advanced Biological Research System (ABRS) facility. TAGES uses Arabidopsis thaliana, thale cress, with sensor promoter-reporter gene constructs that render the plants as biomonitors (an organism used to determine the quality of the surrounding environment) of their environment using real-time nondestructive Green Fluorescent Protein (GFP) imagery and traditional postflight analyses.

  4. Self-consuming innate immunity in Arabidopsis

    DEFF Research Database (Denmark)

    Hofius, Daniel; Mundy, John; Petersen, Morten

    2009-01-01

    . However, it has been unclear by which molecular mechanisms plants execute PCD during innate immune responses. We recently examined HR PCD in autophagy-deficient Arabidopsis knockout mutants (atg) and find that PCD conditioned by one class of plant innate immune receptors is suppressed in atg mutants....... Intriguingly, HR triggered by another class of immune receptors with different genetic requirements is not compromised, indicating that only a specific subset of immune receptors engage the autophagy pathway for HR execution. Thus, our work provides a primary example of autophagic cell death associated...... with innate immune responses in eukaryotes as well as of prodeath functions for the autophagy pathway in plants....

  5. Trichoderma volatiles effecting Arabidopsis

    DEFF Research Database (Denmark)

    Ramadan, Metwaly; Gigolashvili, Tamara; Grosskinsky, Dominik Kilian;

    2015-01-01

    Trichoderma species are present in many ecosystems and some strains have the ability to reduce the severity of plant diseases by activating various defense pathways via specific biologically active signaling molecules. Hence we investigated the effects of low molecular weight volatile compounds...... of Trichoderma asperellum IsmT5 on Arabidopsis thaliana. During co-cultivation of T. asperellum IsmT5 without physical contact to A. thaliana we observed smaller but vital and robust plants. The exposed plants exhibit increased trichome numbers, accumulation of defense-related compounds such as H2O2, anthocyanin......, camalexin, and increased expression of defense-related genes. We conclude that A. thaliana perceives the Trichoderma volatiles as stress compounds and subsequently initiates multilayered adaptations including activation of signaling cascades to withstand this environmental influence. The prominent headspace...

  6. OsSFR6 is a functional rice orthologue of SENSITIVE TO FREEZING-6 and can act as a regulator of COR gene expression, osmotic stress and freezing tolerance in Arabidopsis.

    OpenAIRE

    Wathugala, D.L.; Richards, S.A.; Knight, H; Knight, M.R.

    2011-01-01

    The Arabidopsis protein SENSITIVE TO FREEZING-6 (AtSFR6) is required for cold- and drought-inducible expression of COLD-ON REGULATED (COR) genes and, as a consequence, AtSFR6 is essential for osmotic stress and freezing tolerance in Arabidopsis. Therefore, orthologues of AtSFR6 in crop species represent important candidate targets for future manipulation of stress tolerance. We identified and cloned a homologue of AtSFR6 from rice (Oryza sativa), OsSFR6, and confirmed its orthology in Arabido...

  7. Arabidopsis Rab Geranylgeranyltransferases Demonstrate Redundancy and Broad Substrate Specificity in Vitro.

    Science.gov (United States)

    Shi, Wan; Zeng, Qin; Kunkel, Barbara N; Running, Mark P

    2016-01-15

    Posttranslational lipid modifications mediate the membrane attachment of Rab GTPases, facilitating their function in regulating intracellular vesicular trafficking. In Arabidopsis, most Rab GTPases have two C-terminal cysteines and potentially can be double-geranylgeranylated by heterodimeric Rab geranylgeranyltransferases (Rab-GGTs). Genes encoding two putative α subunits and two putative β subunits of Rab-GGTs have been annotated in the Arabidopsis thaliana genome, but little is known about Rab-GGT activity in Arabidopsis. In this study, we demonstrate that four different heterodimers can be formed between putative Arabidopsis Rab-GGT α subunits RGTA1/RGTA2 and β subunits RGTB1/RGTB2, but only RGTA1·RGTB1 and RGTA1·RGTB2 exhibit bona fide Rab-GGT activity, and they are biochemically redundant in vitro. We hypothesize that RGTA2 function might be disrupted by a 12-amino acid insertion in a conserved motif. We present evidence that Arabidopsis Rab-GGTs may have preference for prenylation of C-terminal cysteines in particular positions. We also demonstrate that Arabidopsis Rab-GGTs can not only prenylate a great variety of Rab GTPases in the presence of Rab escort protein but, unlike Rab-GGT in yeast and mammals, can also prenylate certain non-Rab GTPases independently of Rab escort protein. Our findings may help to explain some of the phenotypes of Arabidopsis protein prenyltransferase mutants. PMID:26589801

  8. ABA Inducible Rice Protein Phosphatase 2C Confers ABA Insensitivity and Abiotic Stress Tolerance in Arabidopsis

    OpenAIRE

    Singh, Amarjeet; Jha, Saroj K.; Bagri, Jayram; Pandey, Girdhar K.

    2015-01-01

    Arabidopsis PP2C belonging to group A have been extensively worked out and known to negatively regulate ABA signaling. However, rice (Oryza sativa) orthologs of Arabidopsis group A PP2C are scarcely characterized functionally. We have identified a group A PP2C from rice (OsPP108), which is highly inducible under ABA, salt and drought stresses and localized predominantly in the nucleus. Genetic analysis revealed that Arabidopsis plants overexpressing OsPP108 are highly insensitive to ABA and t...

  9. Identification and characterization of a salt tolerance-responsive gene( AtGRP9) of Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Soil salinity is one of the important limiting factors for plant growth and development. A cDNA clone encoding a glycine-rich protein (designated AtGRP9) was identified from Arabidopsis by functional expression of the plant cDNA library in the fission yeast S. pombe. Yeast cells overexpressing AtGRP9 displayed significantly enhanced salt tolerance. Northern analysis showed that expression of AtGRP9 in Arabidopsis was induced by NaCl and plant hormone abscisic acid (ABA). These results suggest that AtGRP9 may be involved in the salt stress response in Arabidopsis.

  10. MTHFD1 controls DNA methylation in Arabidopsis

    Science.gov (United States)

    Groth, Martin; Moissiard, Guillaume; Wirtz, Markus; Wang, Haifeng; Garcia-Salinas, Carolina; Ramos-Parra, Perla A.; Bischof, Sylvain; Feng, Suhua; Cokus, Shawn J.; John, Amala; Smith, Danielle C.; Zhai, Jixian; Hale, Christopher J.; Long, Jeff A.; Hell, Ruediger; Díaz de la Garza, Rocío I.; Jacobsen, Steven E.

    2016-01-01

    DNA methylation is an epigenetic mechanism that has important functions in transcriptional silencing and is associated with repressive histone methylation (H3K9me). To further investigate silencing mechanisms, we screened a mutagenized Arabidopsis thaliana population for expression of SDCpro-GFP, redundantly controlled by DNA methyltransferases DRM2 and CMT3. Here, we identify the hypomorphic mutant mthfd1-1, carrying a mutation (R175Q) in the cytoplasmic bifunctional methylenetetrahydrofolate dehydrogenase/methenyltetrahydrofolate cyclohydrolase (MTHFD1). Decreased levels of oxidized tetrahydrofolates in mthfd1-1 and lethality of loss-of-function demonstrate the essential enzymatic role of MTHFD1 in Arabidopsis. Accumulation of homocysteine and S-adenosylhomocysteine, genome-wide DNA hypomethylation, loss of H3K9me and transposon derepression indicate that S-adenosylmethionine-dependent transmethylation is inhibited in mthfd1-1. Comparative analysis of DNA methylation revealed that the CMT3 and CMT2 pathways involving positive feedback with H3K9me are mostly affected. Our work highlights the sensitivity of epigenetic networks to one-carbon metabolism due to their common S-adenosylmethionine-dependent transmethylation and has implications for human MTHFD1-associated diseases. PMID:27291711

  11. Mitotic Exit Function of Polo-like Kinase Cdc5 Is Dependent on Sequential Activation by Cdk1

    Directory of Open Access Journals (Sweden)

    Jose-Antonio Rodriguez-Rodriguez

    2016-05-01

    Full Text Available To complete mitosis, Saccharomyces cerevisiae needs to activate the mitotic phosphatase Cdc14. Two pathways contribute to Cdc14 regulation: FEAR (Cdc14 early anaphase release and MEN (mitotic exit network. Cdc5 polo-like kinase was found to be an important mitotic exit component. However, its specific role in mitotic exit regulation and its involvement in Cdc14 release remain unclear. Here, we provide insight into the mechanism by which Cdc5 contributes to the timely release of Cdc14. Our genetic and biochemical data indicate that Cdc5 acts in parallel with MEN during anaphase. This MEN-independent Cdc5 function requires active separase and activation by Cdk1-dependent phosphorylation. Cdk1 first phosphorylates Cdc5 to activate it in early anaphase, and then, in late anaphase, further phosphorylation of Cdc5 by Cdk1 is needed to promote its MEN-related functions.

  12. Arabidopsis thaliana peroxidase N

    DEFF Research Database (Denmark)

    Mirza, Osman Asghar; Henriksen, A; Ostergaard, L;

    2000-01-01

    The structure of the neutral peroxidase from Arabidopsis thaliana (ATP N) has been determined to a resolution of 1.9 A and a free R value of 20.5%. ATP N has the expected characteristic fold of the class III peroxidases, with a C(alpha) r.m.s.d. of 0.82 A when compared with horseradish peroxidase C...... (HRP C). HRP C is 54% identical to ATP N in sequence. When the structures of four class III plant peroxidases are superimposed, the regions with structural differences are non-randomly distributed; all are located in one half of the molecule. The architecture of the haem pocket of ATP N is very similar...... to that of HRP C, in agreement with the low small-molecule substrate specificity of all class III peroxidases. The structure of ATP N suggests that the pH dependence of the substrate turnover will differ from that of HRP C owing to differences in polarity of the residues in the substrate-access channel. Since...

  13. Analysis of Arabidopsis glutathione-transferases in yeast.

    Science.gov (United States)

    Krajewski, Matthias P; Kanawati, Basem; Fekete, Agnes; Kowalski, Natalie; Schmitt-Kopplin, Philippe; Grill, Erwin

    2013-07-01

    The genome of Arabidopsis thaliana encodes 54 functional glutathione transferases (GSTs), classified in seven clades. Although plant GSTs have been implicated in the detoxification of xenobiotics, such as herbicides, extensive redundancy within this large gene family impedes a functional analysis in planta. In this study, a GST-deficient yeast strain was established as a system for analyzing plant GSTs that allows screening for GST substrates and identifying substrate preferences within the plant GST family. To this end, five yeast genes encoding GSTs and GST-related proteins were simultaneously disrupted. The resulting yeast quintuple mutant showed a strongly reduced conjugation of the GST substrates 1-chloro-2,4-dinitrobenzene (CDNB) and 4-chloro-7-nitro-2,1,3-benzoxadiazole (NBD-Cl). Consistently, the quintuple mutant was hypersensitive to CDNB, and this phenotype was complemented by the inducible expression of Arabidopsis GSTs. The conjugating activity of the plant GSTs was assessed by in vitro enzymatic assays and via analysis of exposed yeast cells. The formation of glutathione adducts with dinitrobenzene was unequivocally verified by stable isotope labeling and subsequent accurate ultrahigh-resolution mass spectrometry (ICR-FTMS). Analysis of Arabidopsis GSTs encompassing six clades and 42 members demonstrated functional expression in yeast by using CDNB and NBD-Cl as model substrates. Subsequently, the established yeast system was explored for its potential to screen the Arabidopsis GST family for conjugation of the fungicide anilazine. Thirty Arabidopsis GSTs were identified that conferred increased levels of glutathionylated anilazine. Efficient anilazine conjugation was observed in the presence of the phi, tau, and theta clade GSTs including AtGSTF2, AtGSTF4, AtGSTF6, AtGSTF8, AtGSTF10, and AtGSTT2, none of which had previously been known to contribute to fungicide detoxification. ICR-FTMS analysis of yeast extracts allowed the simultaneous detection and

  14. ML3: a novel regulator of herbivory-induced responses in Arabidopsis thaliana

    OpenAIRE

    Fridborg, I.; Johansson, A; Lagensjo, J.; Leelarasamee, N.; Floková, K. (Kristýna); Tarkowská, D. (Danuše); Meijer, J.; Bejai, S.

    2013-01-01

    ML (MD2-related lipid recognition) proteins are known to enhance innate immune responses in mammals. This study reports the analysis of the putative ML gene family in Arabidopsis thaliana and suggests a role for the ML3 gene in herbivory-associated responses in plants. Feeding by larvae of the Lepidopteran generalist herbivore Spodoptera littoralis and larvae of the specialist herbivore Plutella xylostella activated ML3 transcription in leaf tissues. ML3 loss-of-function Arabidopsis plants we...

  15. Potential role of Arabidopsis PHP as an accessory subunit of the PAF1 transcriptional cofactor.

    Science.gov (United States)

    Park, Sunchung; Ek-Ramos, Maria Julissa; Oh, Sookyung; van Nocker, Steven

    2011-08-01

    Paf1C is a transcriptional cofactor that has been implicated in various transcription-associated mechanisms spanning initiation, elongation and RNA processing, and is important for multiple aspects of development in Arabidopsis. Our recent studies suggest Arabidopsis Paf1C is crucial for proper regulation of genes within H3K27me3-enriched chromatin, and that a protein named PHP may act as an accessory subunit of Paf1C that promotes this function.

  16. Overexpression of Arabidopsis AnnAt8 Alleviates Abiotic Stress in Transgenic Arabidopsis and Tobacco

    Science.gov (United States)

    Yadav, Deepanker; Ahmed, Israr; Shukla, Pawan; Boyidi, Prasanna; Kirti, Pulugurtha Bharadwaja

    2016-01-01

    Abiotic stress results in massive loss of crop productivity throughout the world. Because of our limited knowledge of the plant defense mechanisms, it is very difficult to exploit the plant genetic resources for manipulation of traits that could benefit multiple stress tolerance in plants. To achieve this, we need a deeper understanding of the plant gene regulatory mechanisms involved in stress responses. Understanding the roles of different members of plant gene families involved in different stress responses, would be a step in this direction. Arabidopsis, which served as a model system for the plant research, is also the most suitable system for the functional characterization of plant gene families. Annexin family in Arabidopsis also is one gene family which has not been fully explored. Eight annexin genes have been reported in the genome of Arabidopsis thaliana. Expression studies of different Arabidopsis annexins revealed their differential regulation under various abiotic stress conditions. AnnAt8 (At5g12380), a member of this family has been shown to exhibit ~433 and ~175 fold increase in transcript levels under NaCl and dehydration stress respectively. To characterize Annexin8 (AnnAt8) further, we have generated transgenic Arabidopsis and tobacco plants constitutively expressing AnnAt8, which were evaluated under different abiotic stress conditions. AnnAt8 overexpressing transgenic plants exhibited higher seed germination rates, better plant growth, and higher chlorophyll retention when compared to wild type plants under abiotic stress treatments. Under stress conditions transgenic plants showed comparatively higher levels of proline and lower levels of malondialdehyde compared to the wild-type plants. Real-Time PCR analyses revealed that the expression of several stress-regulated genes was altered in AnnAt8 over-expressing transgenic tobacco plants, and the enhanced tolerance exhibited by the transgenic plants can be correlated with altered expressions of

  17. Molecular screening tools to study Arabidopsis transcription factors

    Directory of Open Access Journals (Sweden)

    Nora eWehner

    2011-11-01

    Full Text Available In the model plant Arabidopsis thaliana, more than 2000 genes are estimated to encode transcription factors (TFs, which clearly emphasizes the importance of transcriptional control. Although genomic approaches have generated large TF Open Reading Frame (ORF collections, only a limited number of these genes is functionally characterized, yet. This review evaluates strategies and methods to identify TF functions. In particular, we focus on two recently developed TF screening platforms, which make use of publi-cally available GATEWAY® compatible ORF collections. (1 The Arabidopsis thaliana TF ORF over-Expression (AtTORF-Ex library provides pooled collections of transgenic lines over-expressing HA-tagged TF genes, which are suited for screening approaches to define TF functions in stress defense and development. (2 A high-throughput microtiter plate based Protoplast Trans Activation (PTA system has been established to screen for TFs which are regulating a given promoter:Luciferase construct in planta.

  18. Histone Deacetylase Genes in Arabidopsis Development

    Institute of Scientific and Technical Information of China (English)

    Courtney Hollender; Zhongchi Liu

    2008-01-01

    Histone acetylatlon and deacetylation are directly connected with transcriptional activation and silencing in eukaryotas.Gene families for enzymes that accomplish these histone modifications show surprising complexity in domain organization,tissue-specific expression, and function. This review is focused on the family of histone deacetylases (HDACs) that remove the acetyl group from core histone tails, resulting in a "closed" chromatin and transcriptional repression. In Arabidopsis,18 HDAC genes are divided in to three different types - RPD3-1ike, HD-tuin and sirtuin - with two or more members ineach type. The structural feature of each HDAC class, the expression profile of each HDAC gene during development and functional insights of important family members are summarized here. It is clear that HDACs are an important class of global transcriptional regulators that play crucial roles in plant development, defense, and adaptation.

  19. Genetic Analyses of Meiotic Recombination in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Meiosis is essential for sexual reproduction and recombination is a critical step required for normal meiosis. Understanding the underlying molecular mechanisms that regulate recombination ie important for medical, agricultural and ecological reasons. Readily available molecular and cytological tools make Arabidopsis an excellent system to study meiosis. Here we review recent developments in molecular genetic analyses on meiotic recombination. These Include studies on plant homologs of yeast and animal genes, as well as novel genes that were first identified in plants. The characterizations of these genes have demonstrated essential functions from the initiation of recombination by double-strand breaks to repair of such breaks, from the formation of double-Holliday junctions to possible resolution of these junctions, both of which are critical for crossover formation. The recent advances have ushered a new era in plant meiosis, in which the combination of genetics, genomics, and molecular cytology can uncover important gene functions.

  20. Exploiting Natural Variation in Arabidopsis

    NARCIS (Netherlands)

    Molenaar, J.A.; Keurentjes, J.J.B.

    2014-01-01

    Natural variation for many traits is present within the species Arabidopsis thaliana . This chapter describes the use of natural variation to elucidate genes underlying the regulation of quantitative traits. It deals with the development and use of mapping populations, the detection and handling of

  1. Exploiting natural variation in Arabidopsis

    NARCIS (Netherlands)

    J.A. Molenaar; J.J.B. Keurentjes

    2014-01-01

    Natural variation for many traits is present within the species Arabidopsis thaliana. This chapter describes the use of natural variation to elucidate genes underlying the regulation of quantitative traits. It deals with the development and use of mapping populations, the detection and handling of g

  2. Mathematical Modeling and Experimental Validation of the Spatial Distribution of Boron in the Root of Arabidopsis thaliana Identify High Boron Accumulation in the Tip and Predict a Distinct Root Tip Uptake Function

    OpenAIRE

    Shimotohno, Akie; Sotta, Naoyuki; Sato, Takafumi; De Ruvo, Micol; Marée, Athanasius F.M.; Verônica A Grieneisen; Fujiwara, Toru

    2015-01-01

    Boron, an essential micronutrient, is transported in roots of Arabidopsis thaliana mainly by two different types of transporters, BORs and NIPs (nodulin26-like intrinsic proteins). Both are plasma membrane localized, but have distinct transport properties and patterns of cell type-specific accumulation with different polar localizations, which are likely to affect boron distribution. Here, we used mathematical modeling and an experimental determination to address boron distributions in the ro...

  3. P-proteins in Arabidopsis are heteromeric structures involved in rapid sieve tube sealing

    Directory of Open Access Journals (Sweden)

    Stephan B Jekat

    2013-07-01

    Full Text Available Structural phloem proteins (P-proteins are characteristic components of the sieve elements in all dicotyledonous and many monocotyledonous angiosperms. Tobacco P-proteins were recently evidenced to be encoded by the widespread SEO gene family, and tobacco SEO proteins were shown to be directly involved in sieve tube sealing thus preventing the loss of photosynthate. Analysis of the two Arabidopsis SEO proteins (AtSEOa and AtSEOb indicated that the corresponding P-protein subunits do not act in a redundant manner. However, there are still pending questions regarding the interaction properties and specific functions of AtSEOa and AtSEOb as well as the general function of structural P-proteins in Arabidopsis. In this study, we characterized the Arabidopsis P-proteins in more detail. We used in planta bimolecular fluorescence complementation assays to confirm the predicted heteromeric interactions between AtSEOa and AtSEOb. Arabidopsis mutants depleted for one or both AtSEO proteins lacked the typical P-protein structures normally found in sieve elements, underlining the identity of AtSEO proteins as P-proteins and furthermore providing the means to determine the role of Arabidopsis P-proteins in sieve tube sealing. We therefore developed an assay based on phloem exudation. Mutants with reduced AtSEO expression levels lost twice as much photosynthate following injury as comparable wild-type plants, confirming that Arabidopsis P-proteins are indeed involved in sieve tube sealing. 

  4. 拟南芥Psrp-4基因参与光合作用机制的研究%Studies on the Functions of Plastid-specific Ribosomal Protein 4 Gene (Psrp-4) of Arabidopsis in Photosynthesis

    Institute of Scientific and Technical Information of China (English)

    左然; 徐美玲; 温泽文; 张东远

    2012-01-01

    叶绿体核糖体是植物特有的细胞器之一,其主要功能是合成质体基因编码的蛋白质.已有研究表明在叶绿体核糖体内含有6个质体特有蛋白PSRP (plastid-specific ribosomal protein),分别命名为PSRP1~PSRP6.然而,这些蛋白在叶绿体蛋白合成过程以及光合作用中的作用机制研究尚处初级阶段.在本研究中,为了阐明PSRP-4蛋白在叶绿体发育过程中的作用机制,我们利用Gateway系统构建了Psrp-4基因(At2g38140)的RNAi表达载体,转化野生型拟南芥后获得了Psrp-4基因表达量明显降低的psrp-4突变体.研究结果表明:psrp-4突变体比野生型生长略微缓慢,但叶片颜色与野生型差别不大,能够进行正常的光合作用.在高光胁迫条件下,测定psrp-4突变体光合化学效率,发现与野生型差异不明显;进一步的蛋白免疫印记实验证明Psrp-4基因表达量的降低对PSⅡ反应中心D1蛋白的周转也没有明显影响.因此,推测PSRP-4蛋白可能不是叶绿体蛋白合成以及光合作用的正常进行所必需的.%Chloroplast ribosome is an organelle which is specific to plants. Its main function is to synthetize proteins encoded by plastogenes. Study shows that chloroplast ribosome contains six PSRPs (plastid-specific ribosomal proteins), named as PSRP1~PSRP6; however, the study on the functions of those proteins in photosynthesis and protein synthesis in chloroplast is still in its infancy. To investigate the roles of Psrp-4 in chloroplast development, RNAi vector of Psrp-4 gene (At2g38140) which was subsequently transformed into wild type Arabidopsis was constructed using Gateway technology, psrp -4 mutant showedsignificant reduction in expression level. Our results indicated that the growth rate of psrp-4 mutants was slightly lower than the wild type's; however, the leaf color of mutant and wild type plants were identical and photosynthesis in the mutant plants proceeded normally. Under high light treatment

  5. Roles for farnesol and ABA in Arabidopsis flower development

    OpenAIRE

    Fitzpatrick, A. Heather; Shrestha, Nisha; Bhandari, Jayaram; Crowell, Dring N

    2011-01-01

    The Arabidopsis FOLK (At5g58560) gene encodes farnesol kinase, which phosphorylates farnesol to farnesyl phosphate. Loss-of-function mutations in the FOLK gene are associated with enhanced sensitivity to abscisic acid (ABA), suggesting that FOLK negatively regulates ABA signaling. Moreover, folk flowers develop supernumerary carpels under water stress, providing evidence for a molecular link between farnesol metabolism, abiotic stress signaling and flower development. Here, we show that farne...

  6. Epigenetic Control of CACTA Transposon Mobility in Arabidopsis thaliana

    OpenAIRE

    Kato, Masaomi; Takashima, Kazuya; Kakutani, Tetsuji

    2004-01-01

    Epigenetic mutation, heritable developmental variation not based on a change in nucleotide sequence, is widely reported in plants. However, the developmental and evolutionary significance of such mutations remains enigmatic. On the basis of our studies of the endogenous Arabidopsis transposon CACTA, we propose that the inheritance of epigenetic gene silencing over generations can function as a transgenerational genome defense mechanism against deleterious movement of transposons. We previousl...

  7. Arabidopsis Hormone Database: a comprehensive genetic and phenotypic information database for plant hormone research in Arabidopsis.

    Science.gov (United States)

    Peng, Zhi-yu; Zhou, Xin; Li, Linchuan; Yu, Xiangchun; Li, Hongjiang; Jiang, Zhiqiang; Cao, Guangyu; Bai, Mingyi; Wang, Xingchun; Jiang, Caifu; Lu, Haibin; Hou, Xianhui; Qu, Lijia; Wang, Zhiyong; Zuo, Jianru; Fu, Xiangdong; Su, Zhen; Li, Songgang; Guo, Hongwei

    2009-01-01

    Plant hormones are small organic molecules that influence almost every aspect of plant growth and development. Genetic and molecular studies have revealed a large number of genes that are involved in responses to numerous plant hormones, including auxin, gibberellin, cytokinin, abscisic acid, ethylene, jasmonic acid, salicylic acid, and brassinosteroid. Here, we develop an Arabidopsis hormone database, which aims to provide a systematic and comprehensive view of genes participating in plant hormonal regulation, as well as morphological phenotypes controlled by plant hormones. Based on data from mutant studies, transgenic analysis and gene ontology (GO) annotation, we have identified a total of 1026 genes in the Arabidopsis genome that participate in plant hormone functions. Meanwhile, a phenotype ontology is developed to precisely describe myriad hormone-regulated morphological processes with standardized vocabularies. A web interface (http://ahd.cbi.pku.edu.cn) would allow users to quickly get access to information about these hormone-related genes, including sequences, functional category, mutant information, phenotypic description, microarray data and linked publications. Several applications of this database in studying plant hormonal regulation and hormone cross-talk will be presented and discussed. PMID:19015126

  8. An auxin responsive CLE gene regulates shoot apical meristem development in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Hongyan eGuo

    2015-05-01

    Full Text Available Plant hormone auxin regulates most, if not all aspects of plant growth and development, including lateral root formation, organ pattering, apical dominance and tropisms. Peptide hormones are peptides with hormone activities. Some of the functions of peptide hormones in regulating plant growth and development are similar to that of auxin, however, the relationship between auxin and peptide hormones remains largely unknown. Here we report the identification of OsCLE48, a rice (Oryza sativa CLE (CLAVATA3/ENDOSPERM SURROUNDING REGION gene, as an auxin response gene, and the functional characterization of OsCLE48 in Arabidopsis and rice. OsCLE48 encodes a CLE peptide hormone that is similar to Arabidopsis CLEs. RT-PCR analysis showed that OsCLE48 was induced by exogenously application of IAA (indole-3-acetic acid, a naturally occurred auxin. Expression of integrated OsCLE48p:GUS reporter gene in transgenic Arabidopsis plants was also induced by exogenously IAA treatment. These results indicate that OsCLE48 is an auxin responsive gene. Histochemical staining showed that GUS activity was detected in all the tissue and organs of the OsCLE48p:GUS transgenic Arabidopsis plants. Expression of OsCLE48 under the control of the 35S promoter in Arabidopsis inhibited shoot apical meristem development. Expression of OsCLE48 under the control of the CLV3 native regulatory elements almost completely complemented clv3-2 mutant phenotypes, suggesting that OsCLE48 is functionally similar to CLV3. On the other hand, expression of OsCLE48 under the control of the 35S promoter in Arabidopsis has little, if any effects on root apical meristem development, and transgenic rice plants overexpressing OsCLE48 are morphologically indistinguishable from wild type plants, suggesting that the functions of some CLE peptides may not be fully conserved in Arabidopsis and rice.

  9. Asparagine Metabolic Pathways in Arabidopsis.

    Science.gov (United States)

    Gaufichon, Laure; Rothstein, Steven J; Suzuki, Akira

    2016-04-01

    Inorganic nitrogen in the form of ammonium is assimilated into asparagine via multiple steps involving glutamine synthetase (GS), glutamate synthase (GOGAT), aspartate aminotransferase (AspAT) and asparagine synthetase (AS) in Arabidopsis. The asparagine amide group is liberated by the reaction catalyzed by asparaginase (ASPG) and also the amino group of asparagine is released by asparagine aminotransferase (AsnAT) for use in the biosynthesis of amino acids. Asparagine plays a primary role in nitrogen recycling, storage and transport in developing and germinating seeds, as well as in vegetative and senescence organs. A small multigene family encodes isoenzymes of each step of asparagine metabolism in Arabidopsis, except for asparagine aminotransferase encoded by a single gene. The aim of this study is to highlight the structure of the genes and encoded enzyme proteins involved in asparagine metabolic pathways; the regulation and role of different isogenes; and kinetic and physiological properties of encoded enzymes in different tissues and developmental stages. PMID:26628609

  10. Evolution of NIN-like proteins in Arabidopsis, rice, and Lotus japonicus.

    Science.gov (United States)

    Schauser, Leif; Wieloch, Wioletta; Stougaard, Jens

    2005-02-01

    Genetic studies in Lotus japonicus and pea have identified Nin as a core symbiotic gene required for establishing symbiosis between legumes and nitrogen fixing bacteria collectively called Rhizobium. Sequencing of additional Lotus cDNAs combined with analysis of genome sequences from Arabidopsis and rice reveals that Nin homologues in all three species constitute small gene families. In total, the Arabidopsis and rice genomes encode nine and three NIN-like proteins (NLPs), respectively. We present here a bioinformatics analysis and prediction of NLP evolution. On a genome scale we show that in Arabidopsis, this family has evolved through segmental duplication rather than through tandem amplification. Alignment of all predicted NLP protein sequences shows a composition with six conserved modules. In addition, Lotus and pea NLPs contain segments that might characterize NIN proteins of legumes and be of importance for their function in symbiosis. The most conserved region in NLPs, the RWP-RK domain, has secondary structure predictions consistent with DNA binding properties. This motif is shared by several other small proteins in both Arabidopsis and rice. In rice, the RWP-RK domain sequences have diversified significantly more than in Arabidopsis. Database searches reveal that, apart from its presence in Arabidopsis and rice, the motif is also found in the algae Chlamydomonas and in the slime mold Dictyostelium discoideum. Thus, the origin of this putative DNA binding region seems to predate the fungus-plant divide. PMID:15785851

  11. Arabidopsis thaliana—Aphid Interaction

    OpenAIRE

    Louis, Joe; Singh, Vijay,; Shah, Jyoti

    2012-01-01

    Aphids are important pests of plants that use their stylets to tap into the sieve elements to consume phloem sap. Besides the removal of photosynthates, aphid infestation also alters source-sink patterns. Most aphids also vector viral diseases. In this chapter, we will summarize on recent significant findings in plant-aphid interaction, and how studies involving Arabidopsis thaliana and Myzus persicae (Sülzer), more commonly known as the green peach aphid (GPA), are beginning to provide impor...

  12. Stem cell organization in Arabidopsis

    OpenAIRE

    Wendrich, J.R.

    2016-01-01

    Growth of plant tissues and organs depends on continuous production of new cells, by niches of stem cells. Stem cells typically divide to give rise to one differentiating daughter and one non-differentiating daughter. This constant process of self-renewal ensures that the niches of stem cells or meristems stay active throughout plant-life. Specification of stem cells occurs very early during development of the emrbyo and they are maintained during later stages. The Arabidopsis embryo is a hig...

  13. Genome-wide Analysis of Ovate Family Proteins in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Huang Jian-ping; Li Hong-ling; Chang Ying

    2012-01-01

    Arabidopsis thaliana ovate family proteins (AtOFPs) is a newly found plant-specific protein family interacting with TALE (3-aa loop extension homeodomain proteins) homeodomain proteins in Arabidopsis. Here, based on bioinformatic analysis, we found that Arabidopsis genome actually encoded 17 OVATE domain-containing proteins. One of them, AtOFP19, has not been previously identified. Based on their amino acid sequence similarity, AtOFPs proteins can be divided into two groups. Most of the AtOFPs were located in nuclear, four of them were presented in chloroplast and the remaining two members appeared in cytoplasmic. A genome- wide microarray based gene expression analysis involving 47 stages of vegetative and reproductive development revealed that AtOFPs have diverse expression pattems. Investigation of proteins interaction showed that nine AtOFPs only interacted with TALE homeodomain proteins, which are fundamental regulators of plant meristem function and leaf development. Our work could provide important leads toward functional genomics studies of ovate family proteins, which may be involved in a previously unrecognized control mechanism in plant development

  14. Metabolomic Characterization of Knockout Mutants in Arabidopsis: Development of a Metabolite Profiling Database for Knockout Mutants in Arabidopsis1[W][OPEN

    Science.gov (United States)

    Fukushima, Atsushi; Kusano, Miyako; Mejia, Ramon Francisco; Iwasa, Mami; Kobayashi, Makoto; Hayashi, Naomi; Watanabe-Takahashi, Akiko; Narisawa, Tomoko; Tohge, Takayuki; Hur, Manhoi; Wurtele, Eve Syrkin; Nikolau, Basil J.; Saito, Kazuki

    2014-01-01

    Despite recent intensive research efforts in functional genomics, the functions of only a limited number of Arabidopsis (Arabidopsis thaliana) genes have been determined experimentally, and improving gene annotation remains a major challenge in plant science. As metabolite profiling can characterize the metabolomic phenotype of a genetic perturbation in the plant metabolism, it provides clues to the function(s) of genes of interest. We chose 50 Arabidopsis mutants, including a set of characterized and uncharacterized mutants, that resemble wild-type plants. We performed metabolite profiling of the plants using gas chromatography-mass spectrometry. To make the data set available as an efficient public functional genomics tool for hypothesis generation, we developed the Metabolite Profiling Database for Knock-Out Mutants in Arabidopsis (MeKO). It allows the evaluation of whether a mutation affects metabolism during normal plant growth and contains images of mutants, data on differences in metabolite accumulation, and interactive analysis tools. Nonprocessed data, including chromatograms, mass spectra, and experimental metadata, follow the guidelines set by the Metabolomics Standards Initiative and are freely downloadable. Proof-of-concept analysis suggests that MeKO is highly useful for the generation of hypotheses for genes of interest and for improving gene annotation. MeKO is publicly available at http://prime.psc.riken.jp/meko/. PMID:24828308

  15. Arabidopsis CDS blastp result: AK240730 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK240730 J043030K09 At2g32440.1 68415.m03963 ent-kaurenoic acid hydroxylase, putati...ve / cytochrome P450, putative identical to ent-kaurenoic acid hydroxylase / cytochrome P450 CYP88A (GI:1302...1856) [Arabidopsis thaliana]; similar to ent-kaurenoic acid hydroxylase [Arabidopsis thaliana] GI:13021853 2e-11 ...

  16. Arabidopsis CDS blastp result: AK288052 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK288052 J075151I09 At2g32440.1 68415.m03963 ent-kaurenoic acid hydroxylase, putati...ve / cytochrome P450, putative identical to ent-kaurenoic acid hydroxylase / cytochrome P450 CYP88A (GI:1302...1856) [Arabidopsis thaliana]; similar to ent-kaurenoic acid hydroxylase [Arabidopsis thaliana] GI:13021853 6e-14 ...

  17. Arabidopsis CDS blastp result: AK240911 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK240911 J065037E05 At2g32440.1 68415.m03963 ent-kaurenoic acid hydroxylase, putati...ve / cytochrome P450, putative identical to ent-kaurenoic acid hydroxylase / cytochrome P450 CYP88A (GI:1302...1856) [Arabidopsis thaliana]; similar to ent-kaurenoic acid hydroxylase [Arabidopsis thaliana] GI:13021853 4e-22 ...

  18. Arabidopsis CDS blastp result: AK241119 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK241119 J065094C22 At2g32440.1 68415.m03963 ent-kaurenoic acid hydroxylase, putati...ve / cytochrome P450, putative identical to ent-kaurenoic acid hydroxylase / cytochrome P450 CYP88A (GI:1302...1856) [Arabidopsis thaliana]; similar to ent-kaurenoic acid hydroxylase [Arabidopsis thaliana] GI:13021853 2e-13 ...

  19. Arabidopsis CDS blastp result: AK243149 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK243149 J100032I21 At2g32440.1 68415.m03963 ent-kaurenoic acid hydroxylase, putati...ve / cytochrome P450, putative identical to ent-kaurenoic acid hydroxylase / cytochrome P450 CYP88A (GI:1302...1856) [Arabidopsis thaliana]; similar to ent-kaurenoic acid hydroxylase [Arabidopsis thaliana] GI:13021853 7e-12 ...

  20. Arabidopsis CDS blastp result: AK241581 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK241581 J065181K09 At2g32440.1 68415.m03963 ent-kaurenoic acid hydroxylase, putati...ve / cytochrome P450, putative identical to ent-kaurenoic acid hydroxylase / cytochrome P450 CYP88A (GI:1302...1856) [Arabidopsis thaliana]; similar to ent-kaurenoic acid hydroxylase [Arabidopsis thaliana] GI:13021853 4e-15 ...

  1. Arabidopsis CDS blastp result: AK287479 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK287479 J043023O14 At2g32440.1 68415.m03963 ent-kaurenoic acid hydroxylase, putati...ve / cytochrome P450, putative identical to ent-kaurenoic acid hydroxylase / cytochrome P450 CYP88A (GI:1302...1856) [Arabidopsis thaliana]; similar to ent-kaurenoic acid hydroxylase [Arabidopsis thaliana] GI:13021853 1e-17 ...

  2. Using "Arabidopsis" Genetic Sequences to Teach Bioinformatics

    Science.gov (United States)

    Zhang, Xiaorong

    2009-01-01

    This article describes a new approach to teaching bioinformatics using "Arabidopsis" genetic sequences. Several open-ended and inquiry-based laboratory exercises have been designed to help students grasp key concepts and gain practical skills in bioinformatics, using "Arabidopsis" leucine-rich repeat receptor-like kinase (LRR RLK) genetic…

  3. An International Bioinformatics Infrastructure to Underpin the Arabidopsis Community

    Science.gov (United States)

    The future bioinformatics needs of the Arabidopsis community as well as those of other scientific communities that depend on Arabidopsis resources were discussed at a pair of recent meetings held by the Multinational Arabidopsis Steering Committee (MASC) and the North American Arabidopsis Steering C...

  4. Tape-Arabidopsis Sandwich - a simpler Arabidopsis protoplast isolation method

    Directory of Open Access Journals (Sweden)

    Lee Shu-Hong

    2009-11-01

    Full Text Available Abstract Background Protoplasts isolated from leaves are useful materials in plant research. One application, the transient expression of recombinant genes using Arabidopsis mesophyll protoplasts (TEAMP, is currently commonly used for studies of subcellular protein localization, promoter activity, and in vivo protein-protein interactions. This method requires cutting leaves into very thin slivers to collect mesophyll cell protoplasts, a procedure that often causes cell damage, may yield only a few good protoplasts, and is time consuming. In addition, this protoplast isolation method normally requires a large number of leaves derived from plants grown specifically under low-light conditions, which may be a concern when material availability is limited such as with mutant plants, or in large scale experiments. Results In this report, we present a new procedure that we call the Tape-Arabidopsis Sandwich. This is a simple and fast mesophyll protoplast isolation method. Two kinds of tape (Time tape adhered to the upper epidermis and 3 M Magic tape to the lower epidermis are used to make a "Tape-Arabidopsis Sandwich". The Time tape supports the top side of the leaf during manipulation, while tearing off the 3 M Magic tape allows easy removal of the lower epidermal layer and exposes mesophyll cells to cell wall digesting enzymes when the leaf is later incubated in an enzyme solution. The protoplasts released into solution are collected and washed for further use. For TEAMP, plasmids carrying a gene expression cassette for a fluorescent protein can be successfully delivered into protoplasts isolated from mature leaves grown under optimal conditions. Alternatively, these protoplasts may be used for bimolecular fluorescence complementation (BiFC to investigate protein-protein interactions in vivo, or for Western blot analysis. A significant advantage of this protocol over the current method is that it allows the generation of protoplasts in less than 1 hr

  5. The Significance of Hydrogen Sulfide for Arabidopsis Seed Germination.

    Science.gov (United States)

    Baudouin, Emmanuel; Poilevey, Aurélie; Hewage, Nishodi Indiketi; Cochet, Françoise; Puyaubert, Juliette; Bailly, Christophe

    2016-01-01

    Hydrogen sulfide (H2S) recently emerged as an important gaseous signaling molecule in plants. In this study, we investigated the possible functions of H2S in regulating Arabidopsis seed germination. NaHS treatments delayed seed germination in a dose-dependent manner and were ineffective in releasing seed dormancy. Interestingly, endogenous H2S content was enhanced in germinating seeds. This increase was correlated with higher activity of three enzymes (L-cysteine desulfhydrase, D-cysteine desulfhydrase, and β-cyanoalanine synthase) known as sources of H2S in plants. The H2S scavenger hypotaurine and the D/L cysteine desulfhydrase inhibitor propargylglycine significantly delayed seed germination. We analyzed the germinative capacity of des1 seeds mutated in Arabidopsis cytosolic L-cysteine desulfhydrase. Although the mutant seeds do not exhibit germination-evoked H2S formation, they retained similar germination capacity as the wild-type seeds. In addition, des1 seeds responded similarly to temperature and were as sensitive to ABA as wild type seeds. Taken together, these data suggest that, although its metabolism is stimulated upon seed imbibition, H2S plays, if any, a marginal role in regulating Arabidopsis seed germination under standard conditions. PMID:27446159

  6. The Significance of Hydrogen Sulfide for Arabidopsis Seed Germination

    Science.gov (United States)

    Baudouin, Emmanuel; Poilevey, Aurélie; Hewage, Nishodi Indiketi; Cochet, Françoise; Puyaubert, Juliette; Bailly, Christophe

    2016-01-01

    Hydrogen sulfide (H2S) recently emerged as an important gaseous signaling molecule in plants. In this study, we investigated the possible functions of H2S in regulating Arabidopsis seed germination. NaHS treatments delayed seed germination in a dose-dependent manner and were ineffective in releasing seed dormancy. Interestingly, endogenous H2S content was enhanced in germinating seeds. This increase was correlated with higher activity of three enzymes (L-cysteine desulfhydrase, D-cysteine desulfhydrase, and β-cyanoalanine synthase) known as sources of H2S in plants. The H2S scavenger hypotaurine and the D/L cysteine desulfhydrase inhibitor propargylglycine significantly delayed seed germination. We analyzed the germinative capacity of des1 seeds mutated in Arabidopsis cytosolic L-cysteine desulfhydrase. Although the mutant seeds do not exhibit germination-evoked H2S formation, they retained similar germination capacity as the wild-type seeds. In addition, des1 seeds responded similarly to temperature and were as sensitive to ABA as wild type seeds. Taken together, these data suggest that, although its metabolism is stimulated upon seed imbibition, H2S plays, if any, a marginal role in regulating Arabidopsis seed germination under standard conditions.

  7. Proteomics investigation of endogenous S-nitrosylation in Arabidopsis

    International Nuclear Information System (INIS)

    Highlights: ► Identification and quantification of nitrosothiols. ► A first dataset of endogenously nitrosylated cysteines in Arabidopsis cells. ► Nitrosothiols display apolar motifs not located in close vicinity of cysteines. ► Salt stress alters the endogenous nitrosylation of specific cysteines in Arabidopsis. -- Abstract: S-Nitrosylation emerges as an important protein modification in many processes. However, most data were obtained at the protein level after addition of a NO donor, particularly in plants where information about the cysteines nitrosylated in these proteins is scarce. An adapted work-flow, combining the classical biotin switch method and labeling with isotope-coded affinity tags (ICAT), is proposed. Without addition of NO donor, a total of 53 endogenous nitrosocysteines was identified in Arabidopsis cells, in proteins belonging to all cell territories, including membranes, and covering a large panel of functions. This first repertoire of nitrosothiols in plants enabled also preliminary structural description. Three apolar motifs, not located in close vicinity of cysteines and accounting for half the dataset, were detected and are proposed to complement nitrosylation prediction algorithms, poorly trained with plant data to date. Analysis of changes induced by a brief salt stress showed that NaCl modified the nitrosylation level of a small proportion of endogenously nitrosylated proteins and did not concern all nitrosothiols in these proteins. The possible role of some NO targets in the response to salt stress was discussed.

  8. Comparative Proteomic Analysis of Arabidopsis Mature Pollen and Germinated Pollen

    Institute of Scientific and Technical Information of China (English)

    Junjie Zou; Lianfen Song; Wenzheng Zhang; Yi Wang; Songlin Ruan; Wei-Hua Wu

    2009-01-01

    Proteomic analysis was applied to generating the map of Arabidopsis mature pollen proteins and analyzing the differentially expressed proteins that are potentially involved in the regulation of Arabidopsis pollen germination. By applying 2-D electrophoresis and silver staining, we resolved 499 and 494 protein spots from protein samples extracted from pollen grains and pollen tubes, respectively. Using the matrix-assisted laser desorption ionization time-of-flight mass spectrometry method, we identified 189 distinct proteins from 213 protein spots expressed in mature pollen or pollen tubes, and 75 new identified proteins that had not been reported before in research into the Arabidopsis pollen proteome. Comparative analysis revealed that 40 protein spots exhibit reproducible significant changes between mature pollen and pollen tubes. And 21 proteins from 17 downregulated and six upregulated protein spots were identified. Functional category analysis indicated that these differentially expressed proteins mainly involved in signaling, cellular structure, transport, defense/stress responses, transcription, metabolism, and energy production. The patterns of changes at protein level suggested the important roles for energy metabolism-related proteins in pollen tube growth, accompanied by the activation of the stress response pathway and modifications to the cell wall.

  9. Jasmonate Signal Pathway in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Xiao-Yi Shan; Zhi-Long Wang; Daoxin Xie

    2007-01-01

    Jasmonates (JAs), which include jasmonic acid and its cyclopentane derivatives are synthesized from the octadecanoid pathway and widely distributed throughout the plant kingdom. JAs modulate the expression of numerous genes and mediate responses to stress, wounding, insect attack, pathogen infection, and UV damage. They also affect a variety of processes in many plant developmental processes. The JA signal pathway involves two important events: the biosynthesis of JA and the transduction of JA signal. Several important Arabidopsis mutants in jasmonate signal pathway were described in this review.

  10. Subcellular localization and functional domain studies of DEFECTIVE KERNEL1 in maize and Arabidopsis suggest a model for aleurone cell fate specification involving CRINKLY4 and SUPERNUMERARY ALEURONE LAYER1.

    Science.gov (United States)

    Tian, Qing; Olsen, Lene; Sun, Beimeng; Lid, Stein Erik; Brown, Roy C; Lemmon, Betty E; Fosnes, Kjetil; Gruis, Darren Fred; Opsahl-Sorteberg, Hilde-Gunn; Otegui, Marisa S; Olsen, Odd-Arne

    2007-10-01

    DEFECTIVE KERNEL1 (DEK1), which consists of a membrane-spanning region (DEK1-MEM) and a calpain-like Cys proteinase region (DEK1-CALP), is essential for aleurone cell formation at the surface of maize (Zea mays) endosperm. Immunolocalization and FM4-64 dye incubation experiments showed that DEK1 and CRINKLY4 (CR4), a receptor kinase implicated in aleurone cell fate specification, colocalized to plasma membrane and endosomes. SUPERNUMERARY ALEURONE LAYER1 (SAL1), a negative regulator of aleurone cell fate encoding a class E vacuolar sorting protein, colocalized with DEK1 and CR4 in endosomes. Immunogold localization, dual-axis electron tomography, and diffusion of fluorescent dye tracers showed that young aleurone cells established symplastic subdomains through plasmodesmata of larger dimensions than those connecting starchy endosperm cells and that CR4 preferentially associated with plasmodesmata between aleurone cells. Genetic complementation experiments showed that DEK1-CALP failed to restore wild-type phenotypes in maize and Arabidopsis thaliana dek1 mutants, and DEK1-MEM also failed to restore wild-type phenotypes in Arabidopsis dek1-1 mutants. Instead, ectopic expression of DEK1-MEM under the control of the cauliflower mosaic virus 35S promoter gave a dominant negative phenotype. These data suggest a model for aleurone cell fate specification in which DEK1 perceives and/or transmits a positional signal, CR4 promotes the lateral movement of aleurone signaling molecules between aleurone cells, and SAL1 maintains the proper plasma membrane concentration of DEK1 and CR4 proteins via endosome-mediated recycling/degradation.

  11. Ectopic Expression of Pumpkin Gibberellin Oxidases Alters Gibberellin Biosynthesis and Development of Transgenic Arabidopsis Plants1

    Science.gov (United States)

    Radi, Abeer; Lange, Theo; Niki, Tomoya; Koshioka, Masaji; Lange, Maria João Pimenta

    2006-01-01

    Immature pumpkin (Cucurbita maxima) seeds contain gibberellin (GA) oxidases with unique catalytic properties resulting in GAs of unknown function for plant growth and development. Overexpression of pumpkin GA 7-oxidase (CmGA7ox) in Arabidopsis (Arabidopsis thaliana) resulted in seedlings with elongated roots, taller plants that flower earlier with only a little increase in bioactive GA4 levels compared to control plants. In the same way, overexpression of the pumpkin GA 3-oxidase1 (CmGA3ox1) resulted in a GA overdose phenotype with increased levels of endogenous GA4. This indicates that, in Arabidopsis, 7-oxidation and 3-oxidation are rate-limiting steps in GA plant hormone biosynthesis that control plant development. With an opposite effect, overexpression of pumpkin seed-specific GA 20-oxidase1 (CmGA20ox1) in Arabidopsis resulted in dwarfed plants that flower late with reduced levels of GA4 and increased levels of physiological inactive GA17 and GA25 and unexpected GA34 levels. Severe dwarfed plants were obtained by overexpression of the pumpkin GA 2-oxidase1 (CmGA2ox1) in Arabidopsis. This dramatic change in phenotype was accompanied by a considerable decrease in the levels of bioactive GA4 and an increase in the corresponding inactivation product GA34 in comparison to control plants. In this study, we demonstrate the potential of four pumpkin GA oxidase-encoding genes to modulate the GA plant hormone pool and alter plant stature and development. PMID:16384902

  12. Genome wide association mapping for the tolerance to the polyamine oxidase inhibitor guazatine in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Kostadin Evgeniev eAtanasov

    2016-04-01

    Full Text Available Guazatine is a potent inhibitor of polyamine oxidase (PAO activity. In agriculture, guazatine is used as non-systemic contact fungicide efficient in the protection of cereals and citrus fruits against disease. The composition of guazatine is complex, mainly constituted by a mixture of synthetic guanidated polyamines (polyaminoguanidines. Here we have studied the effects from exposure to guazatine in the weed Arabidopsis thaliana. We report that micromolar concentrations of guazatine are sufficient to inhibit growth of Arabidopsis seedlings and induce chlorosis, whereas germination is barely affected. We observed the occurrence of quantitative variation in the response to guazatine between 107 randomly chosen Arabidopsis accessions. This enabled us to undertake genome-wide association (GWA mapping that identified a locus on chromosome one associated with guazatine tolerance. CHLOROPHYLLASE 1 (CLH1 within this locus was studied as candidate gene, together with its paralog (CLH2. The analysis of independent clh1-2, clh1-3, clh2-3, clh2-2 and double clh1-2 clh2-3 mutant alleles indicated that CLH1 and/or CLH2 loss-of-function or expression down-regulation promote guazatine tolerance in Arabidopsis. We report a natural mechanism by which Arabidopsis populations can overcome toxicity by the fungicide guazatine.

  13. Genome Wide Association Mapping for the Tolerance to the Polyamine Oxidase Inhibitor Guazatine in Arabidopsis thaliana.

    Science.gov (United States)

    Atanasov, Kostadin E; Barboza-Barquero, Luis; Tiburcio, Antonio F; Alcázar, Rubén

    2016-01-01

    Guazatine is a potent inhibitor of polyamine oxidase (PAO) activity. In agriculture, guazatine is used as non-systemic contact fungicide efficient in the protection of cereals and citrus fruits against disease. The composition of guazatine is complex, mainly constituted by a mixture of synthetic guanidated polyamines (polyaminoguanidines). Here, we have studied the effects from exposure to guazatine in the weed Arabidopsis thaliana. We report that micromolar concentrations of guazatine are sufficient to inhibit growth of Arabidopsis seedlings and induce chlorosis, whereas germination is barely affected. We observed the occurrence of quantitative variation in the response to guazatine between 107 randomly chosen Arabidopsis accessions. This enabled us to undertake genome-wide association (GWA) mapping that identified a locus on chromosome one associated with guazatine tolerance. CHLOROPHYLLASE 1 (CLH1) within this locus was studied as candidate gene, together with its paralog (CLH2). The analysis of independent clh1-2, clh1-3, clh2-3, clh2-2, and double clh1-2 clh2-3 mutant alleles indicated that CLH1 and/or CLH2 loss-of-function or expression down-regulation promote guazatine tolerance in Arabidopsis. We report a natural mechanism by which Arabidopsis populations can overcome toxicity by the fungicide guazatine. PMID:27092150

  14. Gravity perception and gravitropic response of inflorescence stems in Arabidopsis thaliana

    Science.gov (United States)

    Fukaki, H.; Tasaka, M.

    1999-01-01

    Shoots of higher plants exhibit negative gravitropism. However, little is known about the site of gravity perception in shoots and the molecular mechanisms of shoot gravitropic responses. Our recent analysis using shoot gravitropism1(sgr1)/scarecrow(scr) and sgr7/short-root (shr) mutants in Arabidopsis thaliana indicated that the endodermis is essential for shoot gravitropism and strongly suggested that the endodermis functions as the gravity-sensing cell layer in dicotyledonous plant shoots. In this paper, we present our recent analysis and model of gravity perception and gravitropic response of inflorescence stems in Arabidopsis thaliana.

  15. EMF1, a novel protein involved in the control of shoot architecture and flowering in Arabidopsis

    DEFF Research Database (Denmark)

    Aubert, D.; Chen, L.; Moon, Y.-H.;

    2001-01-01

    shares common motifs that include nuclear localization signals, P-loop, and LXXLL elements. Alteration of EMF1 expression in transgenic plants caused progressive changes in flowering time, shoot determinacy, and inflorescence architecture. EMF1 and its related sequence may belong to a new class......Shoot architecture and flowering time in angiosperms depend on the balanced expression of a large number of flowering time and flower meristem identity genes. Loss-of-function mutations in the Arabidopsis EMBRYONIC FLOWER (EMF) genes cause Arabidopsis to eliminate rosette shoot growth and transform...

  16. An auxin responsive CLE gene regulates shoot apical meristem development in Arabidopsis.

    Science.gov (United States)

    Guo, Hongyan; Zhang, Wei; Tian, Hainan; Zheng, Kaijie; Dai, Xuemei; Liu, Shanda; Hu, Qingnan; Wang, Xianling; Liu, Bao; Wang, Shucai

    2015-01-01

    Plant hormone auxin regulates most, if not all aspects of plant growth and development, including lateral root formation, organ pattering, apical dominance, and tropisms. Peptide hormones are peptides with hormone activities. Some of the functions of peptide hormones in regulating plant growth and development are similar to that of auxin, however, the relationship between auxin and peptide hormones remains largely unknown. Here we report the identification of OsCLE48, a rice (Oryza sativa) CLE (CLAVATA3/ENDOSPERM SURROUNDING REGION) gene, as an auxin response gene, and the functional characterization of OsCLE48 in Arabidopsis and rice. OsCLE48 encodes a CLE peptide hormone that is similar to Arabidopsis CLEs. RT-PCR analysis showed that OsCLE48 was induced by exogenously application of IAA (indole-3-acetic acid), a naturally occurred auxin. Expression of integrated OsCLE48p:GUS reporter gene in transgenic Arabidopsis plants was also induced by exogenously IAA treatment. These results indicate that OsCLE48 is an auxin responsive gene. Histochemical staining showed that GUS activity was detected in all the tissue and organs of the OsCLE48p:GUS transgenic Arabidopsis plants. Expression of OsCLE48 under the control of the 35S promoter in Arabidopsis inhibited shoot apical meristem development. Expression of OsCLE48 under the control of the CLV3 native regulatory elements almost completely complemented clv3-2 mutant phenotypes, suggesting that OsCLE48 is functionally similar to CLV3. On the other hand, expression of OsCLE48 under the control of the 35S promoter in Arabidopsis has little, if any effects on root apical meristem development, and transgenic rice plants overexpressing OsCLE48 are morphologically indistinguishable from wild type plants, suggesting that the functions of some CLE peptides may not be fully conserved in Arabidopsis and rice. Taken together, our results showed that OsCLE48 is an auxin responsive peptide hormone gene, and it regulates shoot apical

  17. Arabidopsis CDS blastp result: AK288065 [KOME

    Lifescience Database Archive (English)

    Full Text Available al to sulfate tansporter Sultr1;3 [Arabidopsis thaliana] GI:10716805; contains Pfam profile PF00916: Sulfate... transporter family; contains Pfam profile PF01740: STAS domain; contains TIGRfam profile TIGR00815: sulfate permease 1e-145 ...

  18. Arabidopsis CDS blastp result: AK061395 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK061395 006-305-E02 At2g02180.1 tobamovirus multiplication protein 3 (TOM3) identical to tobamovirus multip...lication protein (TOM3) GI:15425641 from [Arabidopsis thaliana] 1e-125 ...

  19. Arabidopsis CDS blastp result: AK104882 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK104882 001-044-H04 At2g02180.1 tobamovirus multiplication protein 3 (TOM3) identical to tobamovirus multip...lication protein (TOM3) GI:15425641 from [Arabidopsis thaliana] 1e-119 ...

  20. Arabidopsis CDS blastp result: AK066854 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK066854 J013075C10 At2g02180.1 tobamovirus multiplication protein 3 (TOM3) identical to tobamovirus multipl...ication protein (TOM3) GI:15425641 from [Arabidopsis thaliana] 1e-119 ...

  1. Arabidopsis CDS blastp result: AK101318 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK101318 J033034D12 At2g02180.1 tobamovirus multiplication protein 3 (TOM3) identical to tobamovirus multipl...ication protein (TOM3) GI:15425641 from [Arabidopsis thaliana] 1e-125 ...

  2. Arabidopsis CDS blastp result: AK069960 [KOME

    Lifescience Database Archive (English)

    Full Text Available thyltransferase 1 / caffeic acid/5-hydroxyferulic acid O-methyltransferase (OMT1) identical to O-methyltrans...T1) (Flavonol 3- O-methyltransferase 1) (Caffeic acid/5-hydroxyferulic acid O- methyltransferase) {Arabidopsis thaliana} 5e-60 ...

  3. Arabidopsis CDS blastp result: AK064768 [KOME

    Lifescience Database Archive (English)

    Full Text Available thyltransferase 1 / caffeic acid/5-hydroxyferulic acid O-methyltransferase (OMT1) identical to O-methyltrans...T1) (Flavonol 3- O-methyltransferase 1) (Caffeic acid/5-hydroxyferulic acid O- methyltransferase) {Arabidopsis thaliana} 1e-112 ...

  4. Arabidopsis CDS blastp result: AK061551 [KOME

    Lifescience Database Archive (English)

    Full Text Available ethyltransferase 1 / caffeic acid/5-hydroxyferulic acid O-methyltransferase (OMT1) identical to O-methyltran...MT1) (Flavonol 3- O-methyltransferase 1) (Caffeic acid/5-hydroxyferulic acid O- methyltransferase) {Arabidopsis thaliana} 2e-67 ...

  5. Arabidopsis CDS blastp result: AK104764 [KOME

    Lifescience Database Archive (English)

    Full Text Available ethyltransferase 1 / caffeic acid/5-hydroxyferulic acid O-methyltransferase (OMT1) identical to O-methyltran...MT1) (Flavonol 3- O-methyltransferase 1) (Caffeic acid/5-hydroxyferulic acid O- methyltransferase) {Arabidopsis thaliana} 2e-67 ...

  6. Arabidopsis CDS blastp result: AK098998 [KOME

    Lifescience Database Archive (English)

    Full Text Available thyltransferase 1 / caffeic acid/5-hydroxyferulic acid O-methyltransferase (OMT1) identical to O-methyltrans...T1) (Flavonol 3- O-methyltransferase 1) (Caffeic acid/5-hydroxyferulic acid O- methyltransferase) {Arabidopsis thaliana} 8e-57 ...

  7. Arabidopsis CDS blastp result: AK061859 [KOME

    Lifescience Database Archive (English)

    Full Text Available ethyltransferase 1 / caffeic acid/5-hydroxyferulic acid O-methyltransferase (OMT1) identical to O-methyltran...MT1) (Flavonol 3- O-methyltransferase 1) (Caffeic acid/5-hydroxyferulic acid O- methyltransferase) {Arabidopsis thaliana} 1e-100 ...

  8. Arabidopsis CDS blastp result: AK102695 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK102695 J033103F21 At5g16910.1 cellulose synthase family protein similar to gi:2827143 cellulose... synthase catalytic subunit, Arabidopsis thaliana, gi:9622886 cellulose synthase-7 from Zea mays 0.0 ...

  9. Arabidopsis CDS blastp result: AK102134 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK102134 J033085F12 At5g16910.1 cellulose synthase family protein similar to gi:2827143 cellulose... synthase catalytic subunit, Arabidopsis thaliana, gi:9622886 cellulose synthase-7 from Zea mays 0.0 ...

  10. Arabidopsis CDS blastp result: AK066835 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK066835 J013087I16 At5g16910.1 cellulose synthase family protein similar to gi:2827143 cellulose... synthase catalytic subunit, Arabidopsis thaliana, gi:9622886 cellulose synthase-7 from Zea mays 1e-171 ...

  11. Arabidopsis CDS blastp result: AK065259 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK065259 J013002J18 At5g16910.1 cellulose synthase family protein similar to gi:2827143 cellulose... synthase catalytic subunit, Arabidopsis thaliana, gi:9622886 cellulose synthase-7 from Zea mays 0.0 ...

  12. Arabidopsis CDS blastp result: AK100523 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK100523 J023100P04 At5g16910.1 cellulose synthase family protein similar to gi:2827143 cellulose... synthase catalytic subunit, Arabidopsis thaliana, gi:9622886 cellulose synthase-7 from Zea mays 0.0 ...

  13. Arabidopsis CDS blastp result: AK242550 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242550 J080319D10 At2g35630.1 68415.m04369 microtubule organization 1 protein (MO...R1) identical to microtubule organization 1 protein GI:14317953 from [Arabidopsis thaliana] 5e-44 ...

  14. Arabidopsis CDS blastp result: AK241043 [KOME

    Lifescience Database Archive (English)

    Full Text Available upted by a stop codon, creating non-consensus donor and acceptor splice sites. 2e-41 ... ...tical to SP|P92997 Germin-like protein subfamily 1 member 13 precursor {Arabidopsis thaliana}; exon 2 interr

  15. Arabidopsis CDS blastp result: AK243135 [KOME

    Lifescience Database Archive (English)

    Full Text Available upted by a stop codon, creating non-consensus donor and acceptor splice sites. 7e-43 ... ...tical to SP|P92997 Germin-like protein subfamily 1 member 13 precursor {Arabidopsis thaliana}; exon 2 interr

  16. The fifth international conference on Arabidopsis research

    Energy Technology Data Exchange (ETDEWEB)

    Hangarter, R.; Scholl, R.; Davis, K.; Feldmann, K.

    1993-12-31

    This volume contains abstracts of oral and poster presentations made in conjunction with the Fifth International Conference on Arabidopsis Research held August 19--22, 1993 at the Ohio State University, Columbus, Ohio.

  17. Arabidopsis CDS blastp result: AK101526 [KOME

    Lifescience Database Archive (English)

    Full Text Available ucosaminyltransferase, putative similar to N-acetylglucosaminyltransferase I from Arabidopsis thaliana [gi:5139335]; contains AT-AC non-consensus splice sites at intron 13 1e-179 ...

  18. Arabidopsis CDS blastp result: AK119708 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK119708 002-157-E08 At1g28330.1 dormancy-associated protein, putative (DRM1) identical to dormancy...-associated protein [Arabidopsis thaliana] GI:2995990; similar to dormancy-associated protei

  19. Arabidopsis CDS blastp result: AK060981 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK060981 006-202-H08 At1g28330.1 dormancy-associated protein, putative (DRM1) identical to dormancy...-associated protein [Arabidopsis thaliana] GI:2995990; similar to dormancy-associated protei

  20. Arabidopsis CDS blastp result: AK111576 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK111576 J013075J23 At1g01510.1 C-terminal binding protein (ANGUSTIFOLIA) nearly id...entical to C-terminal binding protein ANGUSTIFOLIA [Arabidopsis thaliana] GI:15408535; contains Pfam profile

  1. Arabidopsis CDS blastp result: AK120838 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK120838 J023022B11 At1g01510.1 C-terminal binding protein (ANGUSTIFOLIA) nearly id...entical to C-terminal binding protein ANGUSTIFOLIA [Arabidopsis thaliana] GI:15408535; contains Pfam profile

  2. Arabidopsis CDS blastp result: AK111921 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK111921 001-013-A10 At1g01510.1 C-terminal binding protein (ANGUSTIFOLIA) nearly i...dentical to C-terminal binding protein ANGUSTIFOLIA [Arabidopsis thaliana] GI:15408535; contains Pfam profil

  3. Profilin Plays a Role in Cell Elongation, Cell Shape Maintenance, and Flowering in Arabidopsis

    DEFF Research Database (Denmark)

    Ramachandran, S.; Christensen, Hans Erik Mølager; Ishimaru, Y.;

    2000-01-01

    carrying a 35S-PFN-1 or 35S-antisense PFN-1 transgene. Etiolated seedlings underexpressing PFN (PFN-U) displayed an overall dwarf phenotype with short hypocotyls whose lengths were 20% to 25% that of wild type (WT) at low temperatures. Light-grown PFN-U plants were smaller in stature and flowered early......Profilin (PFN) is an ubiquitous, low-M-r, actin-binding protein involved in the organization of the cytoskeleton of eukaryotes including higher plants. PFNs are encoded by a multigene family in Arabidopsis. We have analyzed in vivo functions of Arabidopsis PFN by generating transgenic plants...... expressed in the vascular bundles of cotyledons and leaves. Our results show that Arabidopsis PFNs play a role in cell elongation, cell shape maintenance, polarized growth of root hair, and unexpectedly, in determination of flowering time....

  4. Sequence and analysis of chromosome 3 of the plant Arabidopsis thaliana.

    Science.gov (United States)

    Salanoubat, M; Lemcke, K; Rieger, M; Ansorge, W; Unseld, M; Fartmann, B; Valle, G; Blöcker, H; Perez-Alonso, M; Obermaier, B; Delseny, M; Boutry, M; Grivell, L A; Mache, R; Puigdomènech, P; De Simone, V; Choisne, N; Artiguenave, F; Robert, C; Brottier, P; Wincker, P; Cattolico, L; Weissenbach, J; Saurin, W; Quétier, F; Schäfer, M; Müller-Auer, S; Gabel, C; Fuchs, M; Benes, V; Wurmbach, E; Drzonek, H; Erfle, H; Jordan, N; Bangert, S; Wiedelmann, R; Kranz, H; Voss, H; Holland, R; Brandt, P; Nyakatura, G; Vezzi, A; D'Angelo, M; Pallavicini, A; Toppo, S; Simionati, B; Conrad, A; Hornischer, K; Kauer, G; Löhnert, T H; Nordsiek, G; Reichelt, J; Scharfe, M; Schön, O; Bargues, M; Terol, J; Climent, J; Navarro, P; Collado, C; Perez-Perez, A; Ottenwälder, B; Duchemin, D; Cooke, R; Laudie, M; Berger-Llauro, C; Purnelle, B; Masuy, D; de Haan, M; Maarse, A C; Alcaraz, J P; Cottet, A; Casacuberta, E; Monfort, A; Argiriou, A; flores, M; Liguori, R; Vitale, D; Mannhaupt, G; Haase, D; Schoof, H; Rudd, S; Zaccaria, P; Mewes, H W; Mayer, K F; Kaul, S; Town, C D; Koo, H L; Tallon, L J; Jenkins, J; Rooney, T; Rizzo, M; Walts, A; Utterback, T; Fujii, C Y; Shea, T P; Creasy, T H; Haas, B; Maiti, R; Wu, D; Peterson, J; Van Aken, S; Pai, G; Militscher, J; Sellers, P; Gill, J E; Feldblyum, T V; Preuss, D; Lin, X; Nierman, W C; Salzberg, S L; White, O; Venter, J C; Fraser, C M; Kaneko, T; Nakamura, Y; Sato, S; Kato, T; Asamizu, E; Sasamoto, S; Kimura, T; Idesawa, K; Kawashima, K; Kishida, Y; Kiyokawa, C; Kohara, M; Matsumoto, M; Matsuno, A; Muraki, A; Nakayama, S; Nakazaki, N; Shinpo, S; Takeuchi, C; Wada, T; Watanabe, A; Yamada, M; Yasuda, M; Tabata, S

    2000-12-14

    Arabidopsis thaliana is an important model system for plant biologists. In 1996 an international collaboration (the Arabidopsis Genome Initiative) was formed to sequence the whole genome of Arabidopsis and in 1999 the sequence of the first two chromosomes was reported. The sequence of the last three chromosomes and an analysis of the whole genome are reported in this issue. Here we present the sequence of chromosome 3, organized into four sequence segments (contigs). The two largest (13.5 and 9.2 Mb) correspond to the top (long) and the bottom (short) arms of chromosome 3, and the two small contigs are located in the genetically defined centromere. This chromosome encodes 5,220 of the roughly 25,500 predicted protein-coding genes in the genome. About 20% of the predicted proteins have significant homology to proteins in eukaryotic genomes for which the complete sequence is available, pointing to important conserved cellular functions among eukaryotes. PMID:11130713

  5. Arabidopsis CDS blastp result: AK064342 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK064342 002-107-H07 At5g58270.1 mitochondrial half-ABC transporter (STA1) identical to half...-molecule ABC transporter ATM3 GI:9964121 from [Arabidopsis thaliana]; almost identical to mitochondrial half...-ABC transporter STA1 GI:9187883 from [Arabidopsis thaliana]; identical to cDNA mitochondrial half-ABC transporter (STA1 gene)GI:9187882 0.0 ...

  6. Arabidopsis CDS blastp result: AK287662 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK287662 J065112L10 At5g58270.1 68418.m07295 mitochondrial half-ABC transporter (STA1) identical to half...-molecule ABC transporter ATM3 GI:9964121 from [Arabidopsis thaliana]; almost identical to mitochondrial half...-ABC transporter STA1 GI:9187883 from [Arabidopsis thaliana]; identical to cDNA mitochondrial half-ABC transporter (STA1 gene)GI:9187882 1e-65 ...

  7. Arabidopsis CDS blastp result: AK242094 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242094 J075142E09 At5g58270.1 68418.m07295 mitochondrial half-ABC transporter (STA1) identical to half...-molecule ABC transporter ATM3 GI:9964121 from [Arabidopsis thaliana]; almost identical to mitochondrial half...-ABC transporter STA1 GI:9187883 from [Arabidopsis thaliana]; identical to cDNA mitochondrial half-ABC transporter (STA1 gene)GI:9187882 2e-33 ...

  8. Arabidopsis CDS blastp result: AK102879 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK102879 J033112G11 At5g58270.1 mitochondrial half-ABC transporter (STA1) identical to half...-molecule ABC transporter ATM3 GI:9964121 from [Arabidopsis thaliana]; almost identical to mitochondrial half...-ABC transporter STA1 GI:9187883 from [Arabidopsis thaliana]; identical to cDNA mitochondrial half-ABC transporter (STA1 gene)GI:9187882 1e-122 ...

  9. Arabidopsis CDS blastp result: AK287488 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK287488 J043029O04 At5g58270.1 68418.m07295 mitochondrial half-ABC transporter (STA1) identical to half...-molecule ABC transporter ATM3 GI:9964121 from [Arabidopsis thaliana]; almost identical to mitochondrial half...-ABC transporter STA1 GI:9187883 from [Arabidopsis thaliana]; identical to cDNA mitochondrial half-ABC transporter (STA1 gene)GI:9187882 4e-27 ...

  10. Gene Coexpression Analysis Reveals Complex Metabolism of the Monoterpene Alcohol Linalool in Arabidopsis FlowersW

    NARCIS (Netherlands)

    Ginglinger, J.F.; Boachon, B.; Hofer, R.; Paetz, C.; Kollner, T.G.; Miesch, L.; Lugan, R.; Baltenweck, R.; Mutterer, J.; Ullman, P.; Verstappen, F.W.A.; Bouwmeester, H.J.

    2013-01-01

    The cytochrome P450 family encompasses the largest family of enzymes in plant metabolism, and the functions of many of its members in Arabidopsis thaliana are still unknown. Gene coexpression analysis pointed to two P450s that were coexpressed with two monoterpene synthases in flowers and were thus

  11. Rapid kinetic labeling of Arabidopsis cell suspension cultures: Implications for models of lipid export from plastids

    Science.gov (United States)

    T-87 suspension cell cultures are increasingly used in Arabidopsis research, but there are no reports describing their lipid composition or biosynthesis. To evaluate if T-87 cell cultures as a model system for analysis of lipid metabolism, including tests of gene candidate functions, we have deter...

  12. The Golgi localized bifunctional UDP-rhamnose/UDP-galactose transporter family of Arabidopsis

    DEFF Research Database (Denmark)

    Rautengarten, Carsten; Ebert, Berit; Moreno, Ignacio;

    2014-01-01

    that are specifically presumed to deliver the diverse array of nucleotide sugars found in plants. This study has developed a novel approach that enabled functional characterization of six bifunctional UDP-rhamnose (Rha)/UDP-galactose (Gal) transporters from Arabidopsis. An analysis of loss...

  13. Identification of genes affecting the response of tomato and Arabidopsis upon powdery mildew infection

    NARCIS (Netherlands)

    Gao, D.

    2014-01-01

      Many plant species are hosts of powdery mildew fungi, including Arabidopsis and economically important crops such as wheat, barley and tomato. Resistance has been explored using induced mutagenesis and natural variation in the plant species. The isolated genes encompass loss-of-function susc

  14. In vivo localization in Arabidopsis protoplasts and root tissue.

    Science.gov (United States)

    Lee, Myoung Hui; Lee, Yongjik; Hwang, Inhwan

    2013-01-01

    In eukaryotic cells, a large number of proteins are transported to their final destination after translation by a process called intracellular trafficking. Transient gene expression, either in plant protoplasts or in specific plant tissues, is a fast, flexible, and reproducible approach to study the cellular function of proteins, protein subcellular localizations, and protein-protein interactions. Here we describe the general method of protoplast isolation, polyethylene glycol-mediated protoplast transformation and immunostaining of protoplast or intact root tissues for studying the localization of protein in Arabidopsis.

  15. Natural genetic variation in Arabidopsis for responsiveness to plant growth-promoting rhizobacteria.

    Science.gov (United States)

    Wintermans, Paul C A; Bakker, Peter A H M; Pieterse, Corné M J

    2016-04-01

    The plant growth-promoting rhizobacterium (PGPR) Pseudomonas simiae WCS417r stimulates lateral root formation and increases shoot growth in Arabidopsis thaliana (Arabidopsis). These plant growth-stimulating effects are partly caused by volatile organic compounds (VOCs) produced by the bacterium. Here, we performed a genome-wide association (GWA) study on natural genetic variation in Arabidopsis for the ability to profit from rhizobacteria-mediated plant growth-promotion. To this end, 302 Arabidopsis accessions were tested for root architecture characteristics and shoot fresh weight in response to exposure to WCS417r. Although virtually all Arabidopsis accessions tested responded positively to WCS417r, there was a large variation between accessions in the increase in shoot fresh weight, the extra number of lateral roots formed, and the effect on primary root length. Correlation analyses revealed that the bacterially-mediated increase in shoot fresh weight is related to alterations in root architecture. GWA mapping for WCS417r-stimulated changes in root and shoot growth characteristics revealed 10 genetic loci highly associated with the responsiveness of Arabidopsis to the plant growth-promoting activity of WCS417r. Several of the underlying candidate genes have been implicated in important plant growth-related processes. These results demonstrate that plants possess natural genetic variation for the capacity to profit from the plant growth-promoting function of a beneficial rhizobacterium in their rhizosphere. This knowledge is a promising starting point for sustainable breeding strategies for future crops that are better able to maximize profitable functions from their root microbiome.

  16. Natural genetic variation in Arabidopsis for responsiveness to plant growth-promoting rhizobacteria.

    Science.gov (United States)

    Wintermans, Paul C A; Bakker, Peter A H M; Pieterse, Corné M J

    2016-04-01

    The plant growth-promoting rhizobacterium (PGPR) Pseudomonas simiae WCS417r stimulates lateral root formation and increases shoot growth in Arabidopsis thaliana (Arabidopsis). These plant growth-stimulating effects are partly caused by volatile organic compounds (VOCs) produced by the bacterium. Here, we performed a genome-wide association (GWA) study on natural genetic variation in Arabidopsis for the ability to profit from rhizobacteria-mediated plant growth-promotion. To this end, 302 Arabidopsis accessions were tested for root architecture characteristics and shoot fresh weight in response to exposure to WCS417r. Although virtually all Arabidopsis accessions tested responded positively to WCS417r, there was a large variation between accessions in the increase in shoot fresh weight, the extra number of lateral roots formed, and the effect on primary root length. Correlation analyses revealed that the bacterially-mediated increase in shoot fresh weight is related to alterations in root architecture. GWA mapping for WCS417r-stimulated changes in root and shoot growth characteristics revealed 10 genetic loci highly associated with the responsiveness of Arabidopsis to the plant growth-promoting activity of WCS417r. Several of the underlying candidate genes have been implicated in important plant growth-related processes. These results demonstrate that plants possess natural genetic variation for the capacity to profit from the plant growth-promoting function of a beneficial rhizobacterium in their rhizosphere. This knowledge is a promising starting point for sustainable breeding strategies for future crops that are better able to maximize profitable functions from their root microbiome. PMID:26830772

  17. Mass spectrometric imaging as a high-spatial resolution tool for functional genomics: Tissue-specific gene expression of TT7 inferred from heterogeneous distribution of metabolites in Arabidopsis flowers

    Energy Technology Data Exchange (ETDEWEB)

    Korte, Andrew R.; Song, Zhihong; Nikolau, Basil J.; Lee, Young Jin

    2011-12-23

    Laser desorption/ionization (LDI) mass spectrometry imaging (MSI) was used to acquire chemical images of flavonoid metabolites on the surface of wild-type and mutant (tt7) Arabidopsis thaliana flowers. Flavonoids were localized to the petals and carpels of flowers, with tissue heterogeneity in the petals. Specifically, kaempferol and/or its glycosides were abundant in the distal region of petals and quercetin and its downstream flavonoids were highly enriched in the more proximal region of petals. As a result of a mutation in the TT7 gene which blocks the conversion of dihydrokaempferol to dihydroquercetin, the downstream metabolites, quercetin, isohamnetin, and their glycosides, were not observed in the mutant flowers. Instead, the metabolites in an alternative pathway, kaempferol and/or its glycosides, were as highly abundant on the proximal region of the petals as in the distal region. In addition, the combined flavonoid amounts on the proximal region of petals in the wild-type are almost equivalent to the amounts of kaempferol and/or its glycosides in the mutant. This strongly suggests that the expression of the TT7 gene is localized on the proximal part of the petal while the other genes in the upper stream pathway are evenly expressed throughout the petal. Most importantly, this work demonstrates MSI of metabolites can be utilized for the localization of gene expression.

  18. The pattern of polymorphism in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    2005-07-01

    Full Text Available We resequenced 876 short fragments in a sample of 96 individuals of Arabidopsis thaliana that included stock center accessions as well as a hierarchical sample from natural populations. Although A. thaliana is a selfing weed, the pattern of polymorphism in general agrees with what is expected for a widely distributed, sexually reproducing species. Linkage disequilibrium decays rapidly, within 50 kb. Variation is shared worldwide, although population structure and isolation by distance are evident. The data fail to fit standard neutral models in several ways. There is a genome-wide excess of rare alleles, at least partially due to selection. There is too much variation between genomic regions in the level of polymorphism. The local level of polymorphism is negatively correlated with gene density and positively correlated with segmental duplications. Because the data do not fit theoretical null distributions, attempts to infer natural selection from polymorphism data will require genome-wide surveys of polymorphism in order to identify anomalous regions. Despite this, our data support the utility of A. thaliana as a model for evolutionary functional genomics.

  19. Expression pattern of GASA, downstream genes of DELLA, in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    ZHANG ShengChun; WANG XiaoJing

    2008-01-01

    Separation and functional research of related components involved in gibberellins (GAs) signaling are important to clarify the mechanism of GA functioning. Research on the downstream components of DELLA, the key factor of the GA signaling pathway, is limited at present. GASA (GA-Stimulated in Arabidopsis) family contains 15 genes usually regulated by GA in Arabidopsis thaliana. All GASA proteins have a cleavable signal peptide in N terminus and a conserved GASA domain including 12 cysteines in C terminus. RT-PCR analysis revealed that the expression of GASA4 and GASA6 were down-regulated, but GASA1 and GASA9were up-regulated in the DELLA mutants, gai-t6 and rga-24, as well as the double mutant, consisting with the results that GASA4 and GASA6 were induced, but GASA1 and GASA9 were inhibited by exogenous GA3. In addition, the expression patterns of other GASA genes were regulated by GA and ABA, separately or cooperatively. Most of GASA genes were expressed in roots, stems, leaves, flowers and developing siliques. GUS gene driven by the promoters of GASA6, GASA7, GASAS, GASA9, GASA10, GASA11 and GASA12were used as reporters and it was found that all GASA genes expressed in the growing and differentiating organs and abscission zones,suggesting the role of these genes in cell growth and differentiation. This study provided an important basis for functional study of the GASA gene family in the GA and ABA signaling pathway.

  20. AtPIN: Arabidopsis thaliana Protein Interaction Network

    Directory of Open Access Journals (Sweden)

    Silva-Filho Marcio C

    2009-12-01

    Full Text Available Abstract Background Protein-protein interactions (PPIs constitute one of the most crucial conditions to sustain life in living organisms. To study PPI in Arabidopsis thaliana we have developed AtPIN, a database and web interface for searching and building interaction networks based on publicly available protein-protein interaction datasets. Description All interactions were divided into experimentally demonstrated or predicted. The PPIs in the AtPIN database present a cellular compartment classification (C3 which divides the PPI into 4 classes according to its interaction evidence and subcellular localization. It has been shown in the literature that a pair of genuine interacting proteins are generally expected to have a common cellular role and proteins that have common interaction partners have a high chance of sharing a common function. In AtPIN, due to its integrative profile, the reliability index for a reported PPI can be postulated in terms of the proportion of interaction partners that two proteins have in common. For this, we implement the Functional Similarity Weight (FSW calculation for all first level interactions present in AtPIN database. In order to identify target proteins of cytosolic glutamyl-tRNA synthetase (Cyt-gluRS (AT5G26710 we combined two approaches, AtPIN search and yeast two-hybrid screening. Interestingly, the proteins glutamine synthetase (AT5G35630, a disease resistance protein (AT3G50950 and a zinc finger protein (AT5G24930, which has been predicted as target proteins for Cyt-gluRS by AtPIN, were also detected in the experimental screening. Conclusions AtPIN is a friendly and easy-to-use tool that aggregates information on Arabidopsis thaliana PPIs, ontology, and sub-cellular localization, and might be a useful and reliable strategy to map protein-protein interactions in Arabidopsis. AtPIN can be accessed at http://bioinfo.esalq.usp.br/atpin.

  1. Arabidopsis seedling flood-inoculation technique: a rapid and reliable assay for studying plant-bacterial interactions

    Directory of Open Access Journals (Sweden)

    Uppalapati Srinivasa R

    2011-10-01

    Full Text Available Abstract Background The Arabidopsis thaliana-Pseudomonas syringae model pathosystem is one of the most widely used systems to understand the mechanisms of microbial pathogenesis and plant innate immunity. Several inoculation methods have been used to study plant-pathogen interactions in this model system. However, none of the methods reported to date are similar to those occurring in nature and amicable to large-scale mutant screens. Results In this study, we developed a rapid and reliable seedling flood-inoculation method based on young Arabidopsis seedlings grown on MS medium. This method has several advantages over conventional soil-grown plant inoculation assays, including a shorter growth and incubation period, ease of inoculation and handling, uniform infection and disease development, requires less growth chamber space and is suitable for high-throughput screens. In this study we demonstrated the efficacy of the Arabidopsis seedling assay to study 1 the virulence factors of P. syringae pv. tomato DC3000, including type III protein secretion system (TTSS and phytotoxin coronatine (COR; 2 the effector-triggered immunity; and 3 Arabidopsis mutants affected in salicylic acid (SA- and pathogen-associated molecular pattern (PAMPs-mediated pathways. Furthermore, we applied this technique to study nonhost resistance (NHR responses in Arabidopsis using nonhost pathogens, such as P. syringae pv. tabaci, pv. glycinea and pv. tomato T1, and confirmed the functional role of FLAGELLIN-SENSING 2 (FLS2 in NHR. Conclusions The Arabidopsis seedling flood-inoculation assay provides a rapid, efficient and economical method for studying Arabidopsis-Pseudomonas interactions with minimal growth chamber space and time. This assay could also provide an excellent system for investigating the virulence mechanisms of P. syringae. Using this method, we demonstrated that FLS2 plays a critical role in conferring NHR against nonhost pathovars of P. syringae, but not to

  2. Family business: the multidrug-resistance related protein (MRP) ABC transporter genes in Arabidopsis thaliana.

    Science.gov (United States)

    Kolukisaoglu, H Uner; Bovet, Lucien; Klein, Markus; Eggmann, Thomas; Geisler, Markus; Wanke, Dierk; Martinoia, Enrico; Schulz, Burkhard

    2002-11-01

    Despite the completion of the sequencing of the entire genome of Arabidopsis thaliana (L.) Heynh., the exact determination of each single gene and its function remains an open question. This is especially true for multigene families. An approach that combines analysis of genomic structure, expression data and functional genomics to ascertain the role of the members of the multidrug-resistance-related protein ( MRP) gene family, a subfamily of the ATP-binding cassette (ABC) transporters from Arabidopsis is presented. We used cDNA sequencing and alignment-based re-annotation of genomic sequences to define the exact genic structure of all known AtMRP genes. Analysis of promoter regions suggested different induction conditions even for closely related genes. Expression analysis for the entire gene family confirmed these assumptions. Phylogenetic analysis and determination of segmental duplication in the regions of AtMRP genes revealed that the evolution of the extraordinarily high number of ABC transporter genes in plants cannot solely be explained by polyploidisation during the evolution of the Arabidopsis genome. Interestingly MRP genes from Oryza sativa L. (rice; OsMRP) show very similar genomic structures to those from Arabidopsis. Screening of large populations of T-DNA-mutagenised lines of A. thaliana resulted in the isolation of AtMRP insertion mutants. This work opens the way for the defined analysis of a multigene family of important membrane transporters whose broad variety of functions expands their traditional role as cellular detoxifiers. PMID:12430019

  3. Characterization of Arabidopsis calreticulin mutants in response to calcium and salinity stresses

    Institute of Scientific and Technical Information of China (English)

    Zhigang Li; Yangrong Cao; Jinsong Zhang; Shouyi Chen

    2008-01-01

    As an important calcium-binding protein,calreticulin plays an important role in regulating calcium homeostasis in endoplasmic reticulum (ER) of plants.Here,we identified three loss-of-function mutants ofcalreticulin genes in Arabidopsis to demonstrate the function of calreticulin in response to calcium and salinity stresses.There are three genes encoding calreticulin in Arabidopsis,and they are named AtCRT1,2,and 3,respectively.We found that both single mutant of crt3 and double mutant of crtl crt2 were more sensitive to low calcium environment than wild-type Arabidopsis.Moreover,crt3 mutant showed more sensitivity to salt treatment at germination stage,but tolerance to salt stress at later stage compared with wild-type plant.However,there was no obvious growth difference in the mutant crt1 and crt2 compared with wild-type Arabidopsis under calcium and salt stresses.These results suggest that calreticulin functions in plant responses to calcium and salt stresses.

  4. An improved grafting technique for mature Arabidopsis plants demonstrates long-distance shoot-to-root transport of phytochelatins in Arabidopsis.

    Science.gov (United States)

    Chen, Alice; Komives, Elizabeth A; Schroeder, Julian I

    2006-05-01

    Phytochelatins (PCs) are peptides that function in heavy-metal chelation and detoxification in plants and fungi. A recent study showed that PCs have the ability to undergo long-distance transport in a root-to-shoot direction in transgenic Arabidopsis (Arabidopsis thaliana). To determine whether long-distance transport of PCs can occur in the opposite direction, from shoots to roots, the wheat (Triticum aestivum) PC synthase (TaPCS1) gene was expressed under the control of a shoot-specific promoter (CAB2) in an Arabidopsis PC-deficient mutant, cad1-3 (CAB2TaPCS1/cad1-3). Analyses demonstrated that TaPCS1 is expressed only in shoots and that CAB2TaPCS1/cad1-3 lines complement the cadmium (Cd) and arsenic metal sensitivity of cad1-3 shoots. CAB2TaPCS1/cad1-3 plants exhibited higher Cd accumulation in roots and lower Cd accumulation in shoots compared to wild type. Fluorescence HPLC coupled to mass spectrometry analyses directly detected PC2 in the roots of CAB2:TaPCS1/cad1-3 but not in cad1-3 controls, suggesting that PC2 is transported over long distances in the shoot-to-root direction. In addition, wild-type shoot tissues were grafted onto PC synthase cad1-3 atpcs2-1 double loss-of-function mutant root tissues. An Arabidopsis grafting technique for mature plants was modified to obtain an 84% success rate, significantly greater than a previous rate of approximately 11%. Fluorescence HPLC-mass spectrometry showed the presence of PC2, PC3, and PC4 in the root tissue of grafts between wild-type shoots and cad1-3 atpcs2-1 double-mutant roots, demonstrating that PCs are transported over long distances from shoots to roots in Arabidopsis.

  5. Allele-specific virulence attenuation of the Pseudomonas syringae HopZ1a type III effector via the Arabidopsis ZAR1 resistance protein.

    Directory of Open Access Journals (Sweden)

    Jennifer D Lewis

    2010-04-01

    Full Text Available Plant resistance (R proteins provide a robust surveillance system to defend against potential pathogens. Despite their importance in plant innate immunity, relatively few of the approximately 170 R proteins in Arabidopsis have well-characterized resistance specificity. In order to identify the R protein responsible for recognition of the Pseudomonas syringae type III secreted effector (T3SE HopZ1a, we assembled an Arabidopsis R gene T-DNA Insertion Collection (ARTIC from publicly available Arabidopsis thaliana insertion lines and screened it for plants lacking HopZ1a-induced immunity. This reverse genetic screen revealed that the Arabidopsis R protein HOPZ-activated resistance 1 (ZAR1; At3g50950 is required for recognition of HopZ1a in Arabidopsis. ZAR1 belongs to the coiled-coil (CC class of nucleotide binding site and leucine-rich repeat (NBS-LRR containing R proteins; however, the ZAR1 CC domain phylogenetically clusters in a clade distinct from other related Arabidopsis R proteins. ZAR1-mediated immunity is independent of several genes required by other R protein signaling pathways, including NDR1 and RAR1, suggesting that ZAR1 possesses distinct signaling requirements. The closely-related T3SE protein, HopZ1b, is still recognized by zar1 Arabidopsis plants indicating that Arabidopsis has evolved at least two independent R proteins to recognize the HopZ T3SE family. Also, in Arabidopsis zar1 plants HopZ1a promotes P. syringae growth indicative of an ancestral virulence function for this T3SE prior to the evolution of recognition by the host resistance protein ZAR1. Our results demonstrate that the Arabidopsis resistance protein ZAR1 confers allele-specific recognition and virulence attenuation of the Pseudomonas syringae T3SE protein HopZ1a.

  6. Advances in Arabidopsis research in China from 2006 to 2007

    Institute of Scientific and Technical Information of China (English)

    LIANG Yan; ZUO JianRu; YANG WeiCai

    2007-01-01

    @@ Arabidopsis thaliana, a model plant species, has a number of advantages over other plant species as an experimental organism due to many of its genetic and genomic features. The Chinese Arabidopsis community has made significant contributions to plant biology research in recent years[1,2]. In 2006, studies of plant biology in China received more attention than ever before, especially those pertaining to Arabidopsis research. Here we briefly summarize recent advances in Arabidopsis research in China.

  7. Mathematical modeling and experimental validation of the spatial distribution of boron in the root of Arabidopsis thaliana identify high boron accumulation in the tip and predict a distinct root tip uptake function.

    Science.gov (United States)

    Shimotohno, Akie; Sotta, Naoyuki; Sato, Takafumi; De Ruvo, Micol; Marée, Athanasius F M; Grieneisen, Verônica A; Fujiwara, Toru

    2015-04-01

    Boron, an essential micronutrient, is transported in roots of Arabidopsis thaliana mainly by two different types of transporters, BORs and NIPs (nodulin26-like intrinsic proteins). Both are plasma membrane localized, but have distinct transport properties and patterns of cell type-specific accumulation with different polar localizations, which are likely to affect boron distribution. Here, we used mathematical modeling and an experimental determination to address boron distributions in the root. A computational model of the root is created at the cellular level, describing the boron transporters as observed experimentally. Boron is allowed to diffuse into roots, in cells and cell walls, and to be transported over plasma membranes, reflecting the properties of the different transporters. The model predicts that a region around the quiescent center has a higher concentration of soluble boron than other portions. To evaluate this prediction experimentally, we determined the boron distribution in roots using laser ablation-inductivity coupled plasma-mass spectrometry. The analysis indicated that the boron concentration is highest near the tip and is lower in the more proximal region of the meristem zone, similar to the pattern of soluble boron distribution predicted by the model. Our model also predicts that upward boron flux does not continuously increase from the root tip toward the mature region, indicating that boron taken up in the root tip is not efficiently transported to shoots. This suggests that root tip-absorbed boron is probably used for local root growth, and that instead it is the more mature root regions which have a greater role in transporting boron toward the shoots. PMID:25670713

  8. Evidences for involvement of endogenous cAMP in Arabidopsis defense responses to Verticillium toxins

    Institute of Scientific and Technical Information of China (English)

    Jing JIANG; Ling Wen FAN; Wei Hua WU

    2005-01-01

    Although there were reports suggesting the involvement of endogenous cAMP in plant defense signaling cascades,there is no direct evidence supporting this notion yet and the detailed mechanism is unclear. In the present study, we have used pathogenic fungi Verticillium dahliae and Arabidopsis plants as a model system of plant-microb interaction to demonstrate the function of endogenous cAMP in Arabidopsis defense responses. Both V. dahliae inoculation and Verticillium toxins injection induced typical "wilt" symptoms in Arabidopsis seedlings. When either 8-Br-AMP (a membrane permeable cAMP analogue) or salicylic acid (SA) was applied to Arabidopsis, the plants became resistant to V. dahliae toxins. However, addition of 8-Br-AMP did not increase the resistance of Arabidopsis transgenic plants deficient in SA to the toxins, suggesting that cAMP might act upstream of SA in plant defense signaling pathway.Indeed, 8-Br-cAMP and forskolin, an activator of adenylyl cyclase, significantly stimulated the endogenous SA level in plants, whereas DDA, an inhibitor of adenylyl cyclase dramatically reduced toxin-induced SA increase. Both the endogenous cAMP and SA increased significantly in Arabidopsis seedlings treated with toxins. Furthermore, transcription level of pathogenesis-related protein 1 gene (PR1) was strongly induced by both 8-Br-cAMP and the toxin treatment. Taken together, our data demonstrate that endogenous cAMP is involved in plant defense responses against Verticilliumsecreted toxins by regulating the production of the known signal SA in plant defense pathway.

  9. Spatio-temporal expression patterns of Arabidopsis thaliana and Medicago truncatula defensin-like genes.

    Directory of Open Access Journals (Sweden)

    Mesfin Tesfaye

    Full Text Available Plant genomes contain several hundred defensin-like (DEFL genes that encode short cysteine-rich proteins resembling defensins, which are well known antimicrobial polypeptides. Little is known about the expression patterns or functions of many DEFLs because most were discovered recently and hence are not well represented on standard microarrays. We designed a custom Affymetrix chip consisting of probe sets for 317 and 684 DEFLs from Arabidopsis thaliana and Medicago truncatula, respectively for cataloging DEFL expression in a variety of plant organs at different developmental stages and during symbiotic and pathogenic associations. The microarray analysis provided evidence for the transcription of 71% and 90% of the DEFLs identified in Arabidopsis and Medicago, respectively, including many of the recently annotated DEFL genes that previously lacked expression information. Both model plants contain a subset of DEFLs specifically expressed in seeds or fruits. A few DEFLs, including some plant defensins, were significantly up-regulated in Arabidopsis leaves inoculated with Alternaria brassicicola or Pseudomonas syringae pathogens. Among these, some were dependent on jasmonic acid signaling or were associated with specific types of immune responses. There were notable differences in DEFL gene expression patterns between Arabidopsis and Medicago, as the majority of Arabidopsis DEFLs were expressed in inflorescences, while only a few exhibited root-enhanced expression. By contrast, Medicago DEFLs were most prominently expressed in nitrogen-fixing root nodules. Thus, our data document salient differences in DEFL temporal and spatial expression between Arabidopsis and Medicago, suggesting distinct signaling routes and distinct roles for these proteins in the two plant species.

  10. Tethering Complexes in the Arabidopsis Endomembrane System.

    Science.gov (United States)

    Vukašinović, Nemanja; Žárský, Viktor

    2016-01-01

    Targeting of endomembrane transport containers is of the utmost importance for proper land plant growth and development. Given the immobility of plant cells, localized membrane vesicle secretion and recycling are amongst the main processes guiding proper cell, tissue and whole plant morphogenesis. Cell wall biogenesis and modification are dependent on vectorial membrane traffic, not only during normal development, but also in stress responses and in plant defense against pathogens and/or symbiosis. It is surprising how little we know about these processes in plants, from small GTPase regulation to the tethering complexes that act as their effectors. Tethering factors are single proteins or protein complexes mediating first contact between the target membrane and arriving membrane vesicles. In this review we focus on the tethering complexes of the best-studied plant model-Arabidopsis thaliana. Genome-based predictions indicate the presence of all major tethering complexes in plants that are known from a hypothetical last eukaryotic common ancestor (LECA). The evolutionary multiplication of paralogs of plant tethering complex subunits has produced the massively expanded EXO70 family, indicating a subfunctionalization of the terminal exocytosis machinery in land plants. Interpretation of loss of function (LOF) mutant phenotypes has to consider that related, yet clearly functionally-specific complexes often share some common core subunits. It is therefore impossible to conclude with clarity which version of the complex is responsible for the phenotypic deviations observed. Experimental interest in the analysis of plant tethering complexes is growing and we hope to contribute with this review by attracting even more attention to this fascinating field of plant cell biology. PMID:27243010

  11. Tethering complexes in the Arabidopsis endomembrane system

    Directory of Open Access Journals (Sweden)

    Nemanja eVukasinovic

    2016-05-01

    Full Text Available AbstractTargeting of endomembrane transport containers is of the utmost importance for proper land plant growth and development. Given the immobility of plant cells, localized membrane vesicle secretion and recycling are amongst the main processes guiding proper cell, tissue and whole plant morphogenesis. Cell wall biogenesis and modification are dependent on vectorial membrane traffic, not only during normal development, but also in stress responses and in plant defence against pathogens and/or symbiosis. It is surprising how little we know about these processes in plants, from small GTPase regulation to the tethering complexes that act as their effectors. Tethering factors are single proteins or protein complexes mediating first contact between the target membrane and arriving membrane vesicles. In this review we focus on the tethering complexes of the best-studied plant model – Arabidopsis thaliana. Genome-based predictions indicate the presence of all major tethering complexes in plants that are known from a hypothetical last eukaryotic common ancestor (LECA. The evolutionary multiplication of paralogs of plant tethering complex subunits has produced the massively expanded EXO70 family, indicating a subfunctionalization of the terminal exocytosis machinery in land plants. Interpretation of loss of function (LOF mutant phenotypes has to consider that related, yet clearly functionally-specific complexes often share some common core subunits. It is therefore impossible to conclude with clarity which version of the complex is responsible for the phenotypic deviations observed. Experimental interest in the analysis of plant tethering complexes is growing and we hope to contribute with this review by attracting even more attention to this fascinating field of plant cell biology.

  12. Bioavailability of nanoparticulate hematite to Arabidopsis thaliana

    International Nuclear Information System (INIS)

    The environmental effects and bioavailability of nanoparticulate iron (Fe) to plants are currently unknown. Here, plant bioavailability of synthesized hematite Fe nanoparticles was evaluated using Arabidopsis thaliana (A. thaliana) as a model. Over 56-days of growing wild-type A. thaliana, the nanoparticle-Fe and no-Fe treatments had lower plant biomass, lower chlorophyll concentrations, and lower internal Fe concentrations than the Fe-treatment. Results for the no-Fe and nanoparticle-Fe treatments were consistently similar throughout the experiment. These results suggest that nanoparticles (mean diameter 40.9 nm, range 22.3–67.0 nm) were not taken up and therefore not bioavailable to A. thaliana. Over 14-days growing wild-type and transgenic (Type I/II proton pump overexpression) A. thaliana, the Type I plant grew more than the wild-type in the nanoparticle-Fe treatment, suggesting Type I plants cope better with Fe limitation; however, the nanoparticle-Fe and no-Fe treatments had similar growth for all plant types. -- Highlights: ► Iron nanoparticles were synthesized and assessed for bioavailability to Arabidopsis. ► Arabidopsis grew better in the presence of EDTA-bound iron than nanoparticulate iron. ► Arabidopsis grew the same in the presence of nanoparticulate iron compared to no iron. -- Synthesized iron nanoparticles were not bioavailable to Arabidopsis thaliana in agar nutrient media

  13. Overexpression of Late Embryogenesis Abundant 14 enhances Arabidopsis salt stress tolerance

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Fengjuan, E-mail: jfj.5566@163.com; Qi, Shengdong, E-mail: zisexanwu@163.com; Li, Hui, E-mail: 332453593@qq.com; Liu, Pu, E-mail: banbaokezhan@163.com; Li, Pengcheng, E-mail: lpcsdau@163.com; Wu, Changai, E-mail: cawu@sdau.edu.cn; Zheng, Chengchao, E-mail: cczheng@sdau.edu.cn; Huang, Jinguang, E-mail: jghuang@sdau.edu.cn

    2014-11-28

    Highlights: • It is the first time to investigate the biological function of AtLEA14 in salt stress response. • AtLEA14 enhances the salt stress tolerance both in Arabidopsis and yeast. • AtLEA14 responses to salt stress by stabilizing AtPP2-B11, an E3 ligase, under normal or salt stress conditions. - Abstract: Late embryogenesis abundant (LEA) proteins are implicated in various abiotic stresses in higher plants. In this study, we identified a LEA protein from Arabidopsis thaliana, AtLEA14, which was ubiquitously expressed in different tissues and remarkably induced with increased duration of salt treatment. Subcellular distribution analysis demonstrated that AtLEA14 was mainly localized in the cytoplasm. Transgenic Arabidopsis and yeast overexpressing AtLEA14 all exhibited enhanced tolerance to high salinity. The transcripts of salt stress-responsive marker genes (COR15a, KIN1, RD29B and ERD10) were overactivated in AtLEA14 overexpressing lines compared with those in wild type plants under normal or salt stress conditions. In vivo and in vitro analysis showed that AtLEA14 could effectively stabilize AtPP2-B11, an important E3 ligase. These results suggested that AtLEA14 had important protective functions under salt stress conditions in Arabidopsis.

  14. Characterization of the Ubiquitin E2 Enzyme Variant Gene Family in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Yu Zhang; Pei Wen; On-Sun Lau; Xing-Wang Deng

    2007-01-01

    Ubiquitin E2 enzyme variant (UEV) proteins are similar to ubiquitin-conjugating enzyme (E2) in both sequence and structure, but the lack of a catalytic cysteine residue renders them incapable of forming a thiolester linkage with ubiquitin. While the functional roles of several UEVs have been defined in yeast and animal systems, Arabidopsis COP10, a photomorphogenesis repressor, is the only UEV characterized in plants. Phylogenetic analysis revealed that the eight Arabidopsis UEV genes belong to three subfamilies.The expression of those genes is supported by either the presence of ESTs or RT-PCR analysis. We also characterized the other members of the COP10 subfamily, UEV2. Semi-quantitative RT-PCR analysis indicated that the UEV2 transcripts can be detected in most organs of Arabidopsis. Analysis of UEV2::GUS transgenic lines also showed its ubiquitous expression in nearly all the developmental stages of Arabidopsis.Transient expression analysis indicated that the sGFP-UEV2 fusion protein can localize to both the cytoplasm and nucleus. A T-DNA insertion mutant, uev2-1, which abolished the transcription of UEV2, displays no visible phenotype. Further, the cop10-4 uev2-1 double mutant exhibits the same phenotype as the cop10-4mutant in darkness. UEV2 is therefore not functionally redundant with COP10.

  15. The IDA peptide controls abscission in Arabidopsis and Citrus

    Directory of Open Access Journals (Sweden)

    Leandro H Estornell

    2015-11-01

    Full Text Available Organ abscission is an important process in plant development and reproduction. During abscission, changes in cellular adhesion of specialised abscission zone (AZ cells ensure the detachment of infected organs or those no longer serving a function to the plant. In addition, abscission also plays an important role in the release of ripe fruits. Different plant species display distinct patterns and timing of organ shedding, most likely adapted during evolution to their diverse life styles. However, it appears that key regulators of cell separation may have conserved function in different plant species. Here we investigate the functional conservation of the citrus orthologue of the Arabidopsis peptide ligand INFLORESCENCE DEFICIENT IN ABSCISSION (AtIDA, controlling floral organ abscission. We discuss the possible implications of modifying the citrus IDA orthologue for citrus fruit production.

  16. Abundant protein phosphorylation potentially regulates Arabidopsis anther development.

    Science.gov (United States)

    Ye, Juanying; Zhang, Zaibao; You, Chenjiang; Zhang, Xumin; Lu, Jianan; Ma, Hong

    2016-09-01

    As the male reproductive organ of flowering plants, the stamen consists of the anther and filament. Previous studies on stamen development mainly focused on single gene functions by genetic methods or gene expression changes using comparative transcriptomic approaches, especially in model plants such as Arabidopsis thaliana However, studies on Arabidopsis anther protein expression and post-translational modifications are still lacking. Here we report proteomic and phosphoproteomic studies on developing Arabidopsis anthers at stages 4-7 and 8-12. We identified 3908 high-confidence phosphorylation sites corresponding to 1637 phosphoproteins. Among the 1637 phosphoproteins, 493 were newly identified, with 952 phosphorylation sites. Phosphopeptide enrichment prior to LC-MS analysis facilitated the identification of low-abundance proteins and regulatory proteins, thereby increasing the coverage of proteomic analysis, and facilitated the analysis of more regulatory proteins. Thirty-nine serine and six threonine phosphorylation motifs were uncovered from the anther phosphoproteome and further analysis supports that phosphorylation of casein kinase II, mitogen-activated protein kinases, and 14-3-3 proteins is a key regulatory mechanism in anther development. Phosphorylated residues were preferentially located in variable protein regions among family members, but they were they were conserved across angiosperms in general. Moreover, phosphorylation might reduce activity of reactive oxygen species scavenging enzymes and hamper brassinosteroid signaling in early anther development. Most of the novel phosphoproteins showed tissue-specific expression in the anther according to previous microarray data. This study provides a community resource with information on the abundance and phosphorylation status of thousands of proteins in developing anthers, contributing to understanding post-translational regulatory mechanisms during anther development. PMID:27531888

  17. STMP在拟南芥分枝发育过程中的功能鉴定%Functional Analysis of STMP in the Process of the Branch Development in Arabidopsis thaliana

    Institute of Scientific and Technical Information of China (English)

    高梦烛; 张昊; 高静; 王凤茹; 董金皋

    2016-01-01

    拟南芥(Arabidopsis thaliana)中含有脂/固醇结合的相关脂转移蛋白结构域(steroidogenic acute regulatory related lipid transfer,START)的膜相关蛋白(START domain containing-membrane related protein,STMP),STMP是START保守域(第84~295位)功能未知的蛋白质,由440个氨基酸组成、具有跨膜片段、属于磷脂酰胆碱转运蛋白.为明确STMP在拟南芥发育调控过程中的作用,深入了解拟南芥发育调控的分子机理,本研究用35S强启动子启动START结构域,构建START结构域的过表达载体,利用农杆菌(Agrobacterium tumefaciens)侵染花序法把STMP的过表达载体转入野生型拟南芥,获得过表达STMP的转基因拟南芥,并用qRT-PCR技术进行验证;分析转基因拟南芥分枝发育状况,明确STMP在拟南芥分枝调控过程中的作用;用qRT-PCR技术分析STMP的时空表达特性;构建STMP和绿色荧光蛋白(green fluorescent protein,GFP)的融合蛋白载体,把此载体转入野生型拟南芥中,对转基因拟南芥中GFP进行荧光观察,从而对STMP进行亚细胞定位.本研究获得了过表达STMP的转基因株系;过表达STMP的转基因拟南芥分枝比野生型明显增多,突变体stmp的分枝减少;STMP的时空表达特性分析表明,茎中STMP的表达量最高,STMP定位在细胞质膜和细胞质中.结果表明STMP可以促进拟南芥的分枝发育,本研究对完善拟南芥分枝调控机制具有重要的意义,可以为植物株型的定向设计提供理论依据.

  18. Recent Progress in Arabidopsis Research in China: A Preface

    Institute of Scientific and Technical Information of China (English)

    Zhi-Hong Xu

    2006-01-01

    @@ In 2002, a workshop on Arabidopsis research in China was held in Shanghai, when a small group of Chinese plant scientists was working on this model species. Since then, we have witnessed the rapid growth of Arabidopsis research in China. This special issue of Journal of Integrative Plant Biology is dedicated exclusively to the Fourth Workshop on Arabidopsis Research in China, scheduled on November 30, 2005, in Beijing. In addition to reports collected in this special issue, the Chinese Arabidopsis community has been able to make significant contributions to many research fields. Here, I briefly summarize recent advances in Arabidopsis research in China.

  19. Activity Regulation by Heteromerization of Arabidopsis Allene Oxide Cyclase Family Members

    OpenAIRE

    Markus Otto; Christin Naumann; Wolfgang Brandt; Claus Wasternack; Bettina Hause

    2016-01-01

    Jasmonates (JAs) are lipid-derived signals in plant stress responses and development. A crucial step in JA biosynthesis is catalyzed by allene oxide cyclase (AOC). Four genes encoding functional AOCs (AOC1, AOC2, AOC3 and AOC4) have been characterized for Arabidopsis thaliana in terms of organ- and tissue-specific expression, mutant phenotypes, promoter activities and initial in vivo protein interaction studies suggesting functional redundancy and diversification, including first hints at enz...

  20. Expression of aberrant forms of AUXIN RESPONSE FACTOR8 stimulates parthenocarpy in Arabidopsis and tomato.

    Science.gov (United States)

    Goetz, Marc; Hooper, Lauren C; Johnson, Susan D; Rodrigues, Julio Carlyle Macedo; Vivian-Smith, Adam; Koltunow, Anna M

    2007-10-01

    Fruit initiation in Arabidopsis (Arabidopsis thaliana) is generally repressed until fertilization occurs. However, mutations in AUXIN RESPONSE FACTOR8 (ARF8) uncouple fruit initiation from fertilization, resulting in the formation of seedless, parthenocarpic fruit. Here we induced parthenocarpy in wild-type Arabidopsis by introducing either the mutant genomic (g) Atarf8-4 sequence or gAtARF8:beta-glucuronidase translational fusion constructs by plant transformation. Silencing of endogenous AtARF8 transcription was not observed, indicating that the introduced, aberrant ARF8 transcripts were compromising the function of endogenous ARF8 and/or associated factors involved in suppressing fruit initiation. To analyze the role of ARF8 in tomato (Solanum lycopersicum) we initially emasculated 23 tomato cultivars to test for background parthenocarpy. Surprisingly, all had a predisposition to initiate fertilization-independent fruit growth. Expression of gAtarf8-4 in transgenic tomato ('Monalbo') resulted in a significant increase in the number and size of parthenocarpic fruit. Isolation of tomato ARF8 cDNA indicated significant sequence conservation with AtARF8. SlARF8 may therefore control tomato fruit initiation in a similar manner as AtARF8 does in Arabidopsis. Two SlARF8 cDNAs differing in size by 5 bp were found, both arising from the same gene. The smaller cDNA is a splice variant and is also present in Arabidopsis. We propose that low endogenous levels of the splice variant products might interfere with efficient formation/function of a complex repressing fruit initiation, thereby providing an explanation for the observed ovary expansion in tomato and also Arabidopsis after emasculation. Increasing the levels of aberrant Atarf8-4 transcripts may further destabilize formation/function of the complex in a dosage-dependent manner enhancing tomato parthenocarpic fruit initiation frequency and size and mimicking the parthenocarpic dehiscent silique phenotype found in

  1. Amyloplast movement and gravityperception in Arabidopsis endoderm

    Science.gov (United States)

    Tasaka, M.; Saito, T.; Morita, M. T.

    Gravitropism of higher plant is a growth response regulating the orientation of organs elongation, which includes four sequential steps, the perception of gravistimulus, transduction of the physical stimulus to chemical signal, transmission of the signal, and differential cell elongation depending on the signal. To elucidate the molecular mechanism of these steps, we have isolated a number of Arabidopsis mutants with abnormal shoot gravitropic response. zig (zigzag)/sgr4(shoot gravitropism 4) shows little gravitropism in their shoots. Besides, their inflorescence stems elongate in a zigzag-fashion to bend at each node. ZIG encodes a SNARE, AtVTI11. sgr3 with reduced gravitropic response in inflorescence stems had a missense mutation in other SNARE, AtVAM3. These two SNAREs make a complex in the shoot endoderm cells that are gravity-sensing cells, suggesting that the vesicle transport from trans-Golgi network (TGN) to prevacuolar compartment (PVC) and/or vacuole is involved in gravitropism. Abnormal vesicular/vacuolar structures were observed in several tissues of both mutants. Moreover, SGR2 encodes phospholipase A1-like protein that resides in the vacuolar membrane. Endodermis-specific expression of these genes could complement gravitropism in each mutant. In addition, amyloplasts thought to be statoliths localized abnormally in their endoderm cells. These results strongly suggest that formation and function of vacuole in the endoderm cells are important for amyloplasts sedimentation, which is involved in the early process of shoot gravitropism. To reveal this, we constructed vertical stage microscope system to visualize the behavior of amyloplasts and vacuolar membrane in living endodermal cells. We hope to discuss the mechanism of gravity perception after showing their movements.

  2. Mechanical touch responses of Arabidopsis TCH1-3 mutant roots on inclined hard-agar surface

    Science.gov (United States)

    Zha, Guodong; Wang, Bochu; Liu, Junyu; Yan, Jie; Zhu, Liqing; Yang, Xingyan

    2016-01-01

    The gravity-induced mechanical touch stimulus can affect plant root architecture. Mechanical touch responses of plant roots are an important aspect of plant root growth and development. Previous studies have reported that Arabidopsis TCH1-3 genes are involved in mechano-related events, how-ever, the physiological functions of TCH1-3 genes in Arabidopsis root mechanoresponses remain unclear. In the present study, we applied an inclined hard agar plate method to produce mechanical touch stimulus, and provided evidence that altered mechanical environment could influence root growth. Furthermore, tch1-3 Arabidopsis mutants were investigated on inclined agar surfaces to explore the functions of TCH1-3 genes on Arabidopsis root mechanoresponses. The results showed that two tch2 mutants, cml24-2 and cml24-4, exhibited significantly reduced root length, biased skewing, and decreased density of lateral root. In addition, primary root length and density of lateral root of tch3 (cml12-2) was significantly decreased on inclined agar surfaces. This study indicates that the tch2 and tch3 mutants are hypersensitive to mechanical touch stimulus, and TCH2 (CML24-2 and CML24-4) and TCH3 (CML12-2) genes may participate in the mechanical touch response of Arabidopsis roots.

  3. Arabidopsis chloroplast chaperonin 10 is a calmodulin-binding protein

    Science.gov (United States)

    Yang, T.; Poovaiah, B. W.

    2000-01-01

    Calcium regulates diverse cellular activities in plants through the action of calmodulin (CaM). By using (35)S-labeled CaM to screen an Arabidopsis seedling cDNA expression library, a cDNA designated as AtCh-CPN10 (Arabidopsis thaliana chloroplast chaperonin 10) was cloned. Chloroplast CPN10, a nuclear-encoded protein, is a functional homolog of E. coli GroES. It is believed that CPN60 and CPN10 are involved in the assembly of Rubisco, a key enzyme involved in the photosynthetic pathway. Northern analysis revealed that AtCh-CPN10 is highly expressed in green tissues. The recombinant AtCh-CPN10 binds to CaM in a calcium-dependent manner. Deletion mutants revealed that there is only one CaM-binding site in the last 31 amino acids of the AtCh-CPN10 at the C-terminal end. The CaM-binding region in AtCh-CPN10 has higher homology to other chloroplast CPN10s in comparison to GroES and mitochondrial CPN10s, suggesting that CaM may only bind to chloroplast CPN10s. Furthermore, the results also suggest that the calcium/CaM messenger system is involved in regulating Rubisco assembly in the chloroplast, thereby influencing photosynthesis. Copyright 2000 Academic Press.

  4. The RNA-binding protein repertoire of Arabidopsis thaliana

    KAUST Repository

    Marondedze, Claudius

    2016-07-11

    RNA-binding proteins (RBPs) have essential roles in determining the fate of RNA from synthesis to decay and have been studied on a protein-by-protein basis, or computationally based on a number of well-characterised RNA-binding domains. Recently, high-throughput methods enabled the capture of mammalian RNA-binding proteomes. To gain insight into the role of Arabidopsis thaliana RBPs at the systems level, we have employed interactome capture techniques using cells from different ecotypes grown in cultures and leaves. In vivo UV-crosslinking of RNA to RBPs, oligo(dT) capture and mass spectrometry yielded 1,145 different proteins including 550 RBPs that either belong to the functional category ‘RNA-binding’, have known RNA-binding domains or have orthologs identified in mammals, C. elegans, or S. cerevisiae in addition to 595 novel candidate RBPs. We noted specific subsets of RBPs in cultured cells and leaves and a comparison of Arabidopsis, mammalian, C. elegans, and S. cerevisiae RBPs reveals a common set of proteins with a role in intermediate metabolism, as well as distinct differences suggesting that RBPs are also species and tissue specific. This study provides a foundation for studies that will advance our understanding of the biological significance of RBPs in plant developmental and stimulus specific responses.

  5. Mechanisms guiding Polycomb activities during gene silencing in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Chongsheng eHe

    2013-11-01

    Full Text Available Polycomb group (PcG proteins act in an evolutionarily conserved epigenetic pathway that regulates chromatin structures in plants and animals, repressing many developmentally important genes by modifying histones. PcG proteins can form at least two multiprotein complexes: Polycomb repressive complexes 1 and 2 (PRC1 and PRC2, respectively. The functions of Arabidopsis thaliana PRCs have been characterized in multiple stages of development and have diverse roles in response to environmental stimuli. Recently, the mechanism that precisely regulates Arabidopsis PcG activity was extensively studied. In this review, we summarize recent discoveries in the regulations of PcG at the three different layers: the recruitment of PRCs to specific target loci, the polyubiquitination and degradation of PRC2, and the antagonism of PRC2 activity by the Trithorax group proteins. Current knowledge indicates that the powerful activity of the PcG pathway is strictly controlled for specific silencing of target genes during plant development and in response to environmental stimuli.

  6. [Regulation pattern of the FRUITFULL (FUL) gene of Arabidopsis thaliana].

    Science.gov (United States)

    Chu, Tingting; Xie, Hua; Xu, Yong; Ma, Rongcai

    2010-11-01

    FRUITFULL (FUL) is an MADS box gene that functions early in controlling flowering time, meristem identity and cauline leaf morphology and later in carpel and fruit development in Arabidopsis thaliana. In order to clarify the regulation of FUL expression the upstream regulatory region, -2148 bp - +96 bp and the first intron of the FUL gene were cloned, and vectors with a series of deletion of FUL promoter, and the ones fused with the first intron were constructed. Vectors harboring the fusion of cis-acting elements with the constitutive promoters of TUBULIN and ACTIN were also constructed. Beta-Glucuronidase activity assays of the transgenic Arabidopsis plants showed that two cis-elements were involved in the repression of FUL expression, with one of the two being probably the binding site of the transcriptional factor AP1. And the two CArG boxes played a important role in FUL initiation particularly. Furthermore, the first intron of FUL was shown to participate in the development of carpel and stamen as an enhancer.

  7. Acetylsalicylic acid induces programmed cell death in Arabidopsis cell cultures.

    Science.gov (United States)

    García-Heredia, José M; Hervás, Manuel; De la Rosa, Miguel A; Navarro, José A

    2008-06-01

    Acetylsalicylic acid (ASA), a derivative from the plant hormone salicylic acid (SA), is a commonly used drug that has a dual role in animal organisms as an anti-inflammatory and anticancer agent. It acts as an inhibitor of cyclooxygenases (COXs), which catalyze prostaglandins production. It is known that ASA serves as an apoptotic agent on cancer cells through the inhibition of the COX-2 enzyme. Here, we provide evidences that ASA also behaves as an agent inducing programmed cell death (PCD) in cell cultures of the model plant Arabidopsis thaliana, in a similar way than the well-established PCD-inducing agent H(2)O(2), although the induction of PCD by ASA requires much lower inducer concentrations. Moreover, ASA is herein shown to be a more efficient PCD-inducing agent than salicylic acid. ASA treatment of Arabidopsis cells induces typical PCD-linked morphological and biochemical changes, namely cell shrinkage, nuclear DNA degradation, loss of mitochondrial membrane potential, cytochrome c release from mitochondria and induction of caspase-like activity. However, the ASA effect can be partially reverted by jasmonic acid. Taking together, these results reveal the existence of common features in ASA-induced animal apoptosis and plant PCD, and also suggest that there are similarities between the pathways of synthesis and function of prostanoid-like lipid mediators in animal and plant organisms.

  8. An atlas of type I MADS box gene expression during female gametophyte and seed development in Arabidopsis.

    Science.gov (United States)

    Bemer, Marian; Heijmans, Klaas; Airoldi, Chiara; Davies, Brendan; Angenent, Gerco C

    2010-09-01

    Members of the plant type I MADS domain subfamily have been reported to be involved in reproductive development in Arabidopsis (Arabidopsis thaliana). However, from the 61 type I genes in the Arabidopsis genome, only PHERES1, AGAMOUS-LIKE80 (AGL80), DIANA, AGL62, and AGL23 have been functionally characterized, which revealed important roles for these genes during female gametophyte and early seed development. The functions of the other genes are still unknown, despite the fact that the available single T-DNA insertion mutants have been largely investigated. The lack of mutant phenotypes is likely due to a considerable number of recent intrachromosomal duplications in the type I subfamily, resulting in nonfunctional genes in addition to a high level of redundancy. To enable a breakthrough in type I MADS box gene characterization, a framework needs to be established that allows the prediction of the functionality and redundancy of the type I genes. Here, we present a complete atlas of their expression patterns during female gametophyte and seed development in Arabidopsis, deduced from reporter lines containing translational fusions of the genes to green fluorescent protein and beta-glucuronidase. All the expressed genes were revealed to be active in the female gametophyte or developing seed, indicating that the entire type I subfamily is involved in reproductive development in Arabidopsis. Interestingly, expression was predominantly observed in the central cell, antipodal cells, and chalazal endosperm. The combination of our expression results with phylogenetic and protein interaction data allows a better identification of putative redundantly acting genes and provides a useful tool for the functional characterization of the type I MADS box genes in Arabidopsis.

  9. An Atlas of Type I MADS Box Gene Expression during Female Gametophyte and Seed Development in Arabidopsis[W

    Science.gov (United States)

    Bemer, Marian; Heijmans, Klaas; Airoldi, Chiara; Davies, Brendan; Angenent, Gerco C.

    2010-01-01

    Members of the plant type I MADS domain subfamily have been reported to be involved in reproductive development in Arabidopsis (Arabidopsis thaliana). However, from the 61 type I genes in the Arabidopsis genome, only PHERES1, AGAMOUS-LIKE80 (AGL80), DIANA, AGL62, and AGL23 have been functionally characterized, which revealed important roles for these genes during female gametophyte and early seed development. The functions of the other genes are still unknown, despite the fact that the available single T-DNA insertion mutants have been largely investigated. The lack of mutant phenotypes is likely due to a considerable number of recent intrachromosomal duplications in the type I subfamily, resulting in nonfunctional genes in addition to a high level of redundancy. To enable a breakthrough in type I MADS box gene characterization, a framework needs to be established that allows the prediction of the functionality and redundancy of the type I genes. Here, we present a complete atlas of their expression patterns during female gametophyte and seed development in Arabidopsis, deduced from reporter lines containing translational fusions of the genes to green fluorescent protein and β-glucuronidase. All the expressed genes were revealed to be active in the female gametophyte or developing seed, indicating that the entire type I subfamily is involved in reproductive development in Arabidopsis. Interestingly, expression was predominantly observed in the central cell, antipodal cells, and chalazal endosperm. The combination of our expression results with phylogenetic and protein interaction data allows a better identification of putative redundantly acting genes and provides a useful tool for the functional characterization of the type I MADS box genes in Arabidopsis. PMID:20631316

  10. Transcriptional Wiring of Cell Wall-Related Genes in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Marek Mutwil; Colin Ruprecht; Federico M. Giorgi; Martin Bringmann; Bj(o)rn Usadel; Staffan Persson

    2009-01-01

    Transcriptional coordination, or co-expression, of genes may signify functional relatedness of the correspond-ing proteins. For example, several genes involved in secondary cell wall cellulose biosynthesis are co-expressed with genes engaged in the synthesis of xylan, which is a major component of the secondary cell wall. To extend these types of anal-yses, we investigated the co-expression relationships of all Carbohydrate-Active enZYmes (CAZy)-related genes for Arabidopsis thaliana. Thus, the intention was to transcriptionally link different cell wall-related processes to each other, and also to other biological functions. To facilitate easy manual inspection, we have displayed these interactions as networks and matrices, and created a web-based interface (http://aranet.mpimp-golm.mpg.de/corecarb) containing downloadable files for all the transcriptional associations.

  11. Biochemical and structural properties of cyanases from Arabidopsis thaliana and Oryza sativa.

    Science.gov (United States)

    Qian, Dan; Jiang, Lin; Lu, Lu; Wei, Chunhong; Li, Yi

    2011-01-01

    Cyanate is toxic to all organisms. Cyanase converts cyanate to CO₂ and NH₃ in a bicarbonate-dependent reaction. The biophysical functions and biochemical characteristics of plant cyanases are poorly studied, although it has been investigated in a variety of proteobacteria, cyanobacteria and fungi. In this study, we characterised plant cyanases from Arabidopsis thaliana and Oryza sativa (AtCYN and OsCYN). Prokaryotic-expressed AtCYN and OsCYN both showed cyanase activity in vitro. Temperature had a similar influence on the activity of both cyanases, but pH had a differential impact on AtCYN and OsCYN activity. Homology modelling provided models of monomers of AtCYN and OsCYN, and a coimmunoprecipitation assay and gel filtration indicated that AtCYN and OsCYN formed homodecamers. The analysis of single-residue mutants of AtCYN indicated that the conserved catalytic residues also contributed to the stability of the homodecamer. KCNO treatment inhibited Arabidopsis germination and early seedling growth. Plants containing AtCYN or OsCYN exhibited resistance to KCNO stress, which demonstrated that one role of cyanases in plants is detoxification. Transcription level of AtCYN was higher in the flower than in other organs of Arabidopsis. AtCYN transcription was not significantly affected by KCNO treatment in Arabidopsis, but was induced by salt stress. This research broadens our knowledge on plant detoxification of cyanate via cyanase.

  12. ABA inducible rice protein phosphatase 2C confers ABA insensitivity and abiotic stress tolerance in Arabidopsis.

    Science.gov (United States)

    Singh, Amarjeet; Jha, Saroj K; Bagri, Jayram; Pandey, Girdhar K

    2015-01-01

    Arabidopsis PP2C belonging to group A have been extensively worked out and known to negatively regulate ABA signaling. However, rice (Oryza sativa) orthologs of Arabidopsis group A PP2C are scarcely characterized functionally. We have identified a group A PP2C from rice (OsPP108), which is highly inducible under ABA, salt and drought stresses and localized predominantly in the nucleus. Genetic analysis revealed that Arabidopsis plants overexpressing OsPP108 are highly insensitive to ABA and tolerant to high salt and mannitol stresses during seed germination, root growth and overall seedling growth. At adult stage, OsPP108 overexpression leads to high tolerance to salt, mannitol and drought stresses with far better physiological parameters such as water loss, fresh weight, chlorophyll content and photosynthetic potential (Fv/Fm) in transgenic Arabidopsis plants. Expression profile of various stress marker genes in OsPP108 overexpressing plants revealed interplay of ABA dependent and independent pathway for abiotic stress tolerance. Overall, this study has identified a potential rice group A PP2C, which regulates ABA signaling negatively and abiotic stress signaling positively. Transgenic rice plants overexpressing this gene might provide an answer to the problem of low crop yield and productivity during adverse environmental conditions. PMID:25886365

  13. The COP9 signalosome interacts with SCF UFO and participates in Arabidopsis flower development.

    Science.gov (United States)

    Wang, Xiping; Feng, Suhua; Nakayama, Naomi; Crosby, W L; Irish, Vivian; Deng, Xing Wang; Wei, Ning

    2003-05-01

    The COP9 signalosome (CSN) is involved in multiple developmental processes. It interacts with SCF ubiquitin ligases and deconjugates Nedd8/Rub1 from cullins (deneddylation). CSN is highly expressed in Arabidopsis floral tissues. To investigate the role of CSN in flower development, we examined the expression pattern of CSN in developing flowers. We report here that two csn1 partially deficient Arabidopsis strains exhibit aberrant development of floral organs, decline of APETALA3 (AP3) expression, and low fertility in addition to defects in shoot and inflorescence meristems. We show that UNUSUAL FLORAL ORGANS (UFO) forms a SCF(UFO) complex, which is associated with CSN in vivo. Genetic interaction analysis indicates that CSN is necessary for the gain-of-function activity of the F-box protein UFO in AP3 activation and in floral organ transformation. Compared with the previously reported csn5 antisense and csn1 null mutants, partial deficiency of CSN1 causes a reduction in the level of CUL1 in the mutant flowers without an obvious defect in CUL1 deneddylation. We conclude that CSN is an essential regulator of Arabidopsis flower development and suggest that CSN regulates Arabidopsis flower development in part by modulating SCF(UFO)-mediated AP3 activation. PMID:12724534

  14. The COP9 signalosome interacts with SCF UFO and participates in Arabidopsis flower development.

    Science.gov (United States)

    Wang, Xiping; Feng, Suhua; Nakayama, Naomi; Crosby, W L; Irish, Vivian; Deng, Xing Wang; Wei, Ning

    2003-05-01

    The COP9 signalosome (CSN) is involved in multiple developmental processes. It interacts with SCF ubiquitin ligases and deconjugates Nedd8/Rub1 from cullins (deneddylation). CSN is highly expressed in Arabidopsis floral tissues. To investigate the role of CSN in flower development, we examined the expression pattern of CSN in developing flowers. We report here that two csn1 partially deficient Arabidopsis strains exhibit aberrant development of floral organs, decline of APETALA3 (AP3) expression, and low fertility in addition to defects in shoot and inflorescence meristems. We show that UNUSUAL FLORAL ORGANS (UFO) forms a SCF(UFO) complex, which is associated with CSN in vivo. Genetic interaction analysis indicates that CSN is necessary for the gain-of-function activity of the F-box protein UFO in AP3 activation and in floral organ transformation. Compared with the previously reported csn5 antisense and csn1 null mutants, partial deficiency of CSN1 causes a reduction in the level of CUL1 in the mutant flowers without an obvious defect in CUL1 deneddylation. We conclude that CSN is an essential regulator of Arabidopsis flower development and suggest that CSN regulates Arabidopsis flower development in part by modulating SCF(UFO)-mediated AP3 activation.

  15. Cell fate in the Arabidopsis root epidermis is determined by competition between WEREWOLF and CAPRICE.

    Science.gov (United States)

    Song, Sang-Kee; Ryu, Kook Hui; Kang, Yeon Hee; Song, Jae Hyo; Cho, Young-Hee; Yoo, Sang-Dong; Schiefelbein, John; Lee, Myeong Min

    2011-11-01

    The root hair and nonhair cells in the Arabidopsis (Arabidopsis thaliana) root epidermis are specified by a suite of transcriptional regulators. Two of these are WEREWOLF (WER) and CAPRICE (CPC), which encode MYB transcription factors that are required for promoting the nonhair cell fate and the hair cell fate, respectively. However, the precise function and relationship between these transcriptional regulators have not been fully defined experimentally. Here, we examine these issues by misexpressing the WER gene using the GAL4-upstream activation sequence transactivation system. We find that WER overexpression in the Arabidopsis root tip is sufficient to cause epidermal cells to adopt the nonhair cell fate through direct induction of GLABRA2 (GL2) gene expression. We also show that GLABRA3 (GL3) and ENHANCER OF GLABRA3 (EGL3), two closely related bHLH proteins, are required for the action of the overexpressed WER and that WER interacts with these bHLHs in plant cells. Furthermore, we find that CPC suppresses the WER overexpression phenotype quantitatively. These results show that WER acts together with GL3/EGL3 to induce GL2 expression and that WER and CPC compete with one another to define cell fates in the Arabidopsis root epidermis.

  16. The Protein Elicitor PevD1 Enhances Resistance to Pathogens and Promotes Growth in Arabidopsis.

    Science.gov (United States)

    Liu, Mengjie; Khan, Najeeb Ullah; Wang, Ningbo; Yang, Xiufen; Qiu, Dewen

    2016-01-01

    The protein elicitor PevD1, isolated from Verticillium dahlia, could enhance resistance to TMV in tobacco and Verticillium wilt in cotton. Here, the pevd1 gene was over-expressed in wild type (WT) Arabidopsis, and its biological functions were investigated. Our results showed that the transgenic lines were more resistant to Botrytis cinerea and Pseudomonas syringae pv. tomato DC3000 than the WT line was. In transgenic plants, both the germination time and bolting time required were significantly shorter and fresh weights and plant heights were significantly higher than those in the WT line. A transcriptomics study using digital gene expression profiling (DGE) was performed in transgenic and WT Arabidopsis. One hundred and thirty-six differentially expressed genes were identified. In transgenic Arabidopsis, three critical regulators of JA biosynthesis were up-regulated and JA levels were slightly increased. Three important repressors of the ABA-responsive pathway were up-regulated, indicating that ABA signal transduction may be suppressed. One CML and two WRKY TFs involved in Ca(2+)-responsive pathways were up-regulated, indicating that this pathway may have been triggered. In conclusion, we show that PevD1 is involved in regulating several plant endogenous signal transduction pathways and regulatory networks to enhance resistance and promote growth and development in Arabidopsis. PMID:27489497

  17. ABA inducible rice protein phosphatase 2C confers ABA insensitivity and abiotic stress tolerance in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Amarjeet Singh

    Full Text Available Arabidopsis PP2C belonging to group A have been extensively worked out and known to negatively regulate ABA signaling. However, rice (Oryza sativa orthologs of Arabidopsis group A PP2C are scarcely characterized functionally. We have identified a group A PP2C from rice (OsPP108, which is highly inducible under ABA, salt and drought stresses and localized predominantly in the nucleus. Genetic analysis revealed that Arabidopsis plants overexpressing OsPP108 are highly insensitive to ABA and tolerant to high salt and mannitol stresses during seed germination, root growth and overall seedling growth. At adult stage, OsPP108 overexpression leads to high tolerance to salt, mannitol and drought stresses with far better physiological parameters such as water loss, fresh weight, chlorophyll content and photosynthetic potential (Fv/Fm in transgenic Arabidopsis plants. Expression profile of various stress marker genes in OsPP108 overexpressing plants revealed interplay of ABA dependent and independent pathway for abiotic stress tolerance. Overall, this study has identified a potential rice group A PP2C, which regulates ABA signaling negatively and abiotic stress signaling positively. Transgenic rice plants overexpressing this gene might provide an answer to the problem of low crop yield and productivity during adverse environmental conditions.

  18. Post-transcriptional gene silencing signal could move rapidly and bidirectionally in grafted Arabidopsis thaliana

    Institute of Scientific and Technical Information of China (English)

    LI Ming; JIANG Shiling; WANG Youqun; LIU Guoqin

    2006-01-01

    RNA interference (RNAi), one of the newly found ways for post-transcriptional gene silencing, has been widely used to investigate gene functions through transgenic methods for introducing an RNA silencing signal into plants. In the present study, we constructed a dexamethazone (DEX)-inducible RNAi binary vector harboring a specific sequence fragment (168-bp) homologous to KatB and KatC, two kinesin isoform genes of Arabidopsis, which were proved to result in the post-transcriptional gene silencing of KatB and KatC in DEX-induced transgenic plants. RT-PCR and Northern blot analysis on transgenic homozygous Arabidopsis (termed as RNAi-type plants) showed that DEX inducement causes KatB and KatC mRNA degradation. With a simplified method, Arabidopsis grafting was effectively performed between RNAi-type and wild-type lines. The target gene mRNA levels were tested based on semi-quantitative RT-PCR. Our results demonstrateed that DEX-induced gene silencing signals could result in a reduction in KatB and KatC mRNA in the wild-type rootstocks or scions, indicating that silencing signals of RNAi could be transmitted bidirectionally across the graft junction whether RNAi-plants were scions or stocks. In contrast to the previously reported results on grafted tobacco, the transmission of post- transcriptional gene silencing signals caused by RNAi in grafted Arabidopsis is more effective than that in tobacco.

  19. Analysis and visualization of Arabidopsis thaliana GWAS using web 2.0 technologies.

    Science.gov (United States)

    Huang, Yu S; Horton, Matthew; Vilhjálmsson, Bjarni J; Seren, Umit; Meng, Dazhe; Meyer, Christopher; Ali Amer, Muhammad; Borevitz, Justin O; Bergelson, Joy; Nordborg, Magnus

    2011-01-01

    With large-scale genomic data becoming the norm in biological studies, the storing, integrating, viewing and searching of such data have become a major challenge. In this article, we describe the development of an Arabidopsis thaliana database that hosts the geographic information and genetic polymorphism data for over 6000 accessions and genome-wide association study (GWAS) results for 107 phenotypes representing the largest collection of Arabidopsis polymorphism data and GWAS results to date. Taking advantage of a series of the latest web 2.0 technologies, such as Ajax (Asynchronous JavaScript and XML), GWT (Google-Web-Toolkit), MVC (Model-View-Controller) web framework and Object Relationship Mapper, we have created a web-based application (web app) for the database, that offers an integrated and dynamic view of geographic information, genetic polymorphism and GWAS results. Essential search functionalities are incorporated into the web app to aid reverse genetics research. The database and its web app have proven to be a valuable resource to the Arabidopsis community. The whole framework serves as an example of how biological data, especially GWAS, can be presented and accessed through the web. In the end, we illustrate the potential to gain new insights through the web app by two examples, showcasing how it can be used to facilitate forward and reverse genetics research. Database URL: http://arabidopsis.usc.edu/

  20. Biochemical and structural properties of cyanases from Arabidopsis thaliana and Oryza sativa.

    Directory of Open Access Journals (Sweden)

    Dan Qian

    Full Text Available Cyanate is toxic to all organisms. Cyanase converts cyanate to CO₂ and NH₃ in a bicarbonate-dependent reaction. The biophysical functions and biochemical characteristics of plant cyanases are poorly studied, although it has been investigated in a variety of proteobacteria, cyanobacteria and fungi. In this study, we characterised plant cyanases from Arabidopsis thaliana and Oryza sativa (AtCYN and OsCYN. Prokaryotic-expressed AtCYN and OsCYN both showed cyanase activity in vitro. Temperature had a similar influence on the activity of both cyanases, but pH had a differential impact on AtCYN and OsCYN activity. Homology modelling provided models of monomers of AtCYN and OsCYN, and a coimmunoprecipitation assay and gel filtration indicated that AtCYN and OsCYN formed homodecamers. The analysis of single-residue mutants of AtCYN indicated that the conserved catalytic residues also contributed to the stability of the homodecamer. KCNO treatment inhibited Arabidopsis germination and early seedling growth. Plants containing AtCYN or OsCYN exhibited resistance to KCNO stress, which demonstrated that one role of cyanases in plants is detoxification. Transcription level of AtCYN was higher in the flower than in other organs of Arabidopsis. AtCYN transcription was not significantly affected by KCNO treatment in Arabidopsis, but was induced by salt stress. This research broadens our knowledge on plant detoxification of cyanate via cyanase.

  1. Arabidopsis CDS blastp result: AK073532 [KOME

    Lifescience Database Archive (English)

    Full Text Available ical to ARL2 G-protein (Halimasch; HAL; TITAN5) GI:20514265 from [Arabidopsis thaliana]; identical to cDNA A...AK073532 J033046D12 At2g18390.1 ADP-ribosylation factor-like protein 2 (ARL2) ident

  2. Arabidopsis CDS blastp result: AK061294 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK061294 006-301-D01 At3g08900.1 reversibly glycosylated polypeptide-3 (RGP3) nearl...y identical to reversibly glycosylated polypeptide-3 [Arabidopsis thaliana] GI:11863238; contains non-consensus GA-donor splice site at intron 2 0.0 ...

  3. Protease gene families in Populus and Arabidopsis

    Directory of Open Access Journals (Sweden)

    Jansson Stefan

    2006-12-01

    Full Text Available Abstract Background Proteases play key roles in plants, maintaining strict protein quality control and degrading specific sets of proteins in response to diverse environmental and developmental stimuli. Similarities and differences between the proteases expressed in different species may give valuable insights into their physiological roles and evolution. Results We have performed a comparative analysis of protease genes in the two sequenced dicot genomes, Arabidopsis thaliana and Populus trichocarpa by using genes coding for proteases in the MEROPS database 1 for Arabidopsis to identify homologous sequences in Populus. A multigene-based phylogenetic analysis was performed. Most protease families were found to be larger in Populus than in Arabidopsis, reflecting recent genome duplication. Detailed studies on e.g. the DegP, Clp, FtsH, Lon, rhomboid and papain-Like protease families showed the pattern of gene family expansion and gene loss was complex. We finally show that different Populus tissues express unique suites of protease genes and that the mRNA levels of different classes of proteases change along a developmental gradient. Conclusion Recent gene family expansion and contractions have made the Arabidopsis and Populus complements of proteases different and this, together with expression patterns, gives indications about the roles of the individual gene products or groups of proteases.

  4. Arabidopsis CDS blastp result: AK066153 [KOME

    Lifescience Database Archive (English)

    Full Text Available pC almost identical to ClpC GI:2921158 from [Arabidopsis thaliana]; contains Pfam profile PF02861: Clp amino... terminal domain; contains Pfam profile PF00004: ATPase, AAA family; contains Pfam profile PF02151: UvrB/uvrC motif 0.0 ...

  5. Arabidopsis CDS blastp result: AK287906 [KOME

    Lifescience Database Archive (English)

    Full Text Available subunit / ClpC almost identical to ClpC GI:2921158 from [Arabidopsis thaliana]; contains Pfam profile PF028...61: Clp amino terminal domain; contains Pfam profile PF00004: ATPase, AAA family; contains Pfam profile PF02151: UvrB/uvrC motif 0.0 ...

  6. Arabidopsis CDS blastp result: AK100126 [KOME

    Lifescience Database Archive (English)

    Full Text Available pC almost identical to ClpC GI:2921158 from [Arabidopsis thaliana]; contains Pfam profile PF02861: Clp amino... terminal domain; contains Pfam profile PF00004: ATPase, AAA family; contains Pfam profile PF02151: UvrB/uvrC motif 0.0 ...

  7. Arabidopsis CDS blastp result: AK058510 [KOME

    Lifescience Database Archive (English)

    Full Text Available lpC almost identical to ClpC GI:2921158 from [Arabidopsis thaliana]; contains Pfam profile PF02861: Clp amin...o terminal domain; contains Pfam profile PF00004: ATPase, AAA family; contains Pfam profile PF02151: UvrB/uvrC motif 0.0 ...

  8. Arabidopsis CDS blastp result: AK069552 [KOME

    Lifescience Database Archive (English)

    Full Text Available pC almost identical to ClpC GI:2921158 from [Arabidopsis thaliana]; contains Pfam profile PF02861: Clp amino... terminal domain; contains Pfam profile PF00004: ATPase, AAA family; contains Pfam profile PF02151: UvrB/uvrC motif 0.0 ...

  9. Arabidopsis CDS blastp result: AK062711 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK062711 001-106-C02 At5g37770.1 touch-responsive protein / calmodulin-related protein 2, touch...-induced (TCH2) identical to calmodulin-related protein 2,touch-induced SP:P25070 from [Arabidopsis thaliana] 9e-34 ...

  10. Arabidopsis CDS blastp result: AK242428 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242428 J080089P09 At5g37770.1 68418.m04547 touch-responsive protein / calmodulin-related protein 2, touch...-induced (TCH2) identical to calmodulin-related protein 2,touch-induced SP:P25070 from [Arabidopsis thaliana] 9e-19 ...

  11. Arabidopsis CDS blastp result: AK242346 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242346 J080012M07 At2g41100.2 68415.m05077 touch-responsive protein / calmodulin-related protein 3, touch...-induced (TCH3) identical to calmodulin-related protein 3, touch-induced SP:P25071 from [Arabidopsis thaliana] 3e-44 ...

  12. Arabidopsis CDS blastp result: AK242346 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242346 J080012M07 At5g37770.1 68418.m04547 touch-responsive protein / calmodulin-related protein 2, touch...-induced (TCH2) identical to calmodulin-related protein 2,touch-induced SP:P25070 from [Arabidopsis thaliana] 2e-11 ...

  13. Arabidopsis CDS blastp result: AK243656 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK243656 J100088L22 At2g41100.1 68415.m05076 touch-responsive protein / calmodulin-related protein 3, touch...-induced (TCH3) identical to calmodulin-related protein 3, touch-induced SP:P25071 from [Arabidopsis thaliana] 1e-19 ...

  14. Arabidopsis CDS blastp result: AK242428 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242428 J080089P09 At2g41100.1 68415.m05076 touch-responsive protein / calmodulin-related protein 3, touch...-induced (TCH3) identical to calmodulin-related protein 3, touch-induced SP:P25071 from [Arabidopsis thaliana] 8e-18 ...

  15. Arabidopsis CDS blastp result: AK243656 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK243656 J100088L22 At2g41100.1 68415.m05076 touch-responsive protein / calmodulin-related protein 3, touch...-induced (TCH3) identical to calmodulin-related protein 3, touch-induced SP:P25071 from [Arabidopsis thaliana] 2e-17 ...

  16. Arabidopsis CDS blastp result: AK288095 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK288095 J075191E21 At2g41100.2 68415.m05077 touch-responsive protein / calmodulin-related protein 3, touch...-induced (TCH3) identical to calmodulin-related protein 3, touch-induced SP:P25071 from [Arabidopsis thaliana] 2e-15 ...

  17. Arabidopsis CDS blastp result: AK108506 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK108506 002-143-H11 At5g37770.1 touch-responsive protein / calmodulin-related protein 2, touch...-induced (TCH2) identical to calmodulin-related protein 2,touch-induced SP:P25070 from [Arabidopsis thaliana] 7e-14 ...

  18. Arabidopsis CDS blastp result: AK241786 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK241786 J065207F05 At5g37770.1 68418.m04547 touch-responsive protein / calmodulin-related protein 2, touch...-induced (TCH2) identical to calmodulin-related protein 2,touch-induced SP:P25070 from [Arabidopsis thaliana] 1e-19 ...

  19. Arabidopsis CDS blastp result: AK242346 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242346 J080012M07 At2g41100.1 68415.m05076 touch-responsive protein / calmodulin-related protein 3, touch...-induced (TCH3) identical to calmodulin-related protein 3, touch-induced SP:P25071 from [Arabidopsis thaliana] 8e-44 ...

  20. Arabidopsis CDS blastp result: AK242346 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242346 J080012M07 At2g41100.1 68415.m05076 touch-responsive protein / calmodulin-related protein 3, touch...-induced (TCH3) identical to calmodulin-related protein 3, touch-induced SP:P25071 from [Arabidopsis thaliana] 3e-26 ...

  1. Arabidopsis CDS blastp result: AK242346 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242346 J080012M07 At2g41100.2 68415.m05077 touch-responsive protein / calmodulin-related protein 3, touch...-induced (TCH3) identical to calmodulin-related protein 3, touch-induced SP:P25071 from [Arabidopsis thaliana] 3e-26 ...

  2. Arabidopsis CDS blastp result: AK242428 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242428 J080089P09 At2g41100.2 68415.m05077 touch-responsive protein / calmodulin-related protein 3, touch...-induced (TCH3) identical to calmodulin-related protein 3, touch-induced SP:P25071 from [Arabidopsis thaliana] 3e-16 ...

  3. Arabidopsis CDS blastp result: AK071661 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK071661 J023105D07 At5g37770.1 touch-responsive protein / calmodulin-related protein 2, touch...-induced (TCH2) identical to calmodulin-related protein 2,touch-induced SP:P25070 from [Arabidopsis thaliana] 3e-33 ...

  4. Arabidopsis CDS blastp result: AK242428 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242428 J080089P09 At2g41100.1 68415.m05076 touch-responsive protein / calmodulin-related protein 3, touch...-induced (TCH3) identical to calmodulin-related protein 3, touch-induced SP:P25071 from [Arabidopsis thaliana] 2e-14 ...

  5. Arabidopsis CDS blastp result: AK242346 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242346 J080012M07 At5g37770.1 68418.m04547 touch-responsive protein / calmodulin-related protein 2, touch...-induced (TCH2) identical to calmodulin-related protein 2,touch-induced SP:P25070 from [Arabidopsis thaliana] 2e-25 ...

  6. Arabidopsis CDS blastp result: AK242346 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242346 J080012M07 At2g41100.1 68415.m05076 touch-responsive protein / calmodulin-related protein 3, touch...-induced (TCH3) identical to calmodulin-related protein 3, touch-induced SP:P25071 from [Arabidopsis thaliana] 4e-41 ...

  7. Arabidopsis CDS blastp result: AK288095 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK288095 J075191E21 At2g41100.1 68415.m05076 touch-responsive protein / calmodulin-related protein 3, touch...-induced (TCH3) identical to calmodulin-related protein 3, touch-induced SP:P25071 from [Arabidopsis thaliana] 2e-16 ...

  8. Arabidopsis CDS blastp result: AK243656 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK243656 J100088L22 At2g41100.2 68415.m05077 touch-responsive protein / calmodulin-related protein 3, touch...-induced (TCH3) identical to calmodulin-related protein 3, touch-induced SP:P25071 from [Arabidopsis thaliana] 5e-20 ...

  9. Arabidopsis CDS blastp result: AK243230 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK243230 J100044L04 At1g19850.1 68414.m02490 transcription factor MONOPTEROS (MP) /... auxin-responsive protein (IAA24) / auxin response factor 5 (ARF5) identical to transcription factor MONOPTEROS (MP/IAA24/ARF5) SP:P93024 from [Arabidopsis thaliana] 2e-65 ...

  10. Arabidopsis CDS blastp result: AK103452 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK103452 J033129I11 At1g19850.1 transcription factor MONOPTEROS (MP) / auxin-respon...sive protein (IAA24) / auxin response factor 5 (ARF5) identical to transcription factor MONOPTEROS (MP/IAA24/ARF5) SP:P93024 from [Arabidopsis thaliana] 1e-166 ...

  11. Arabidopsis CDS blastp result: AK318617 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK318617 J100090H20 At1g19850.1 68414.m02490 transcription factor MONOPTEROS (MP) /... auxin-responsive protein (IAA24) / auxin response factor 5 (ARF5) identical to transcription factor MONOPTEROS (MP/IAA24/ARF5) SP:P93024 from [Arabidopsis thaliana] 2e-63 ...

  12. Arabidopsis CDS blastp result: AK289177 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK289177 J100024E07 At1g62360.1 68414.m07036 homeobox protein SHOOT MERISTEMLESS (S...TM) identical to homeobox protein SHOOT MERISTEMLESS (STM) SP:Q38874 from [Arabidopsis thaliana] 7e-29 ...

  13. Arabidopsis CDS blastp result: AK241312 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK241312 J065141L09 At1g62360.1 68414.m07036 homeobox protein SHOOT MERISTEMLESS (S...TM) identical to homeobox protein SHOOT MERISTEMLESS (STM) SP:Q38874 from [Arabidopsis thaliana] 3e-40 ...

  14. Arabidopsis CDS blastp result: AK243352 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK243352 J100060L07 At1g62360.1 68414.m07036 homeobox protein SHOOT MERISTEMLESS (S...TM) identical to homeobox protein SHOOT MERISTEMLESS (STM) SP:Q38874 from [Arabidopsis thaliana] 1e-28 ...

  15. Arabidopsis CDS blastp result: AK241438 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK241438 J065162G03 At1g62360.1 68414.m07036 homeobox protein SHOOT MERISTEMLESS (S...TM) identical to homeobox protein SHOOT MERISTEMLESS (STM) SP:Q38874 from [Arabidopsis thaliana] 7e-29 ...

  16. Arabidopsis CDS blastp result: AK058585 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK058585 001-017-G01 At3g57040.1 two-component responsive regulator / response reactor... 4 (RR4) identical to responce reactor4 GI:3273202 from [Arabidopsis thaliana]; contains Pfam profile: PF00072 response regulator receiver domain 6e-55 ...

  17. Arabidopsis CDS blastp result: AK101721 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK101721 J033061A20 At3g57040.1 two-component responsive regulator / response reactor... 4 (RR4) identical to responce reactor4 GI:3273202 from [Arabidopsis thaliana]; contains Pfam profile: PF00072 response regulator receiver domain 9e-49 ...

  18. Arabidopsis CDS blastp result: AK241055 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK241055 J065063N18 At3g58780.1 68416.m06551 agamous-like MADS box protein AGL1 / shatterproof... 1 (AGL1) (SHP1) identical to SP|P29381 Agamous-like MADS box protein AGL1 (Protein Shatterproof 1) {Arabidopsis thaliana} 1e-26 ...

  19. Arabidopsis CDS blastp result: AK241644 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK241644 J065189M04 At3g58780.1 68416.m06551 agamous-like MADS box protein AGL1 / shatterproof... 1 (AGL1) (SHP1) identical to SP|P29381 Agamous-like MADS box protein AGL1 (Protein Shatterproof 1) {Arabidopsis thaliana} 3e-37 ...

  20. Arabidopsis CDS blastp result: AK242980 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242980 J090094F15 At3g58780.1 68416.m06551 agamous-like MADS box protein AGL1 / shatterproof... 1 (AGL1) (SHP1) identical to SP|P29381 Agamous-like MADS box protein AGL1 (Protein Shatterproof 1) {Arabidopsis thaliana} 2e-19 ...

  1. Arabidopsis CDS blastp result: AK243669 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK243669 J100089N11 At3g58780.1 68416.m06551 agamous-like MADS box protein AGL1 / shatterproof... 1 (AGL1) (SHP1) identical to SP|P29381 Agamous-like MADS box protein AGL1 (Protein Shatterproof 1) {Arabidopsis thaliana} 6e-14 ...

  2. Arabidopsis CDS blastp result: AK242211 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242211 J075171C16 At3g58780.1 68416.m06551 agamous-like MADS box protein AGL1 / shatterproof... 1 (AGL1) (SHP1) identical to SP|P29381 Agamous-like MADS box protein AGL1 (Protein Shatterproof 1) {Arabidopsis thaliana} 5e-21 ...

  3. Arabidopsis CDS blastp result: AK121261 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK121261 J023104H13 At1g55350.4 calpain-type cysteine protease family identical to calpain...-like protein GI:20268660 from [Arabidopsis thaliana]; contains Pfam profiles: PF00648 Calpain family... cysteine protease, PF01067 Calpain large subunit,domain III; identical to cDNA calpain-like protein GI:20268659 0.0 ...

  4. Shotgun Proteomic Analysis of Arabidopsis thaliana Leaves

    Science.gov (United States)

    Two shotgun tandem mass spectrometry proteomics approaches, Multidimensional Protein Identification Technology (MudPIT) and 1D-Gel-LC-MS/MS, were used to identify Arabidopsis thaliana leaf proteins. These methods utilize different protein/peptide separation strategies. Detergents not compatible wit...

  5. Arabidopsis CDS blastp result: AK241281 [KOME

    Lifescience Database Archive (English)

    Full Text Available ctor, putative / enhancer of shoot regeneration (ESR1) similar to gb|D38124 EREBP-3 from Nicotiana tabacum a...nd contains PF|00847 AP2 domain; identical to cDNA enhancer of shoot regeneration ESR1 GI:18028939, enhancer of shoot regeneration ESR1 [Arabidopsis thaliana] GI:18028940 1e-12 ...

  6. Arabidopsis CDS blastp result: AK242986 [KOME

    Lifescience Database Archive (English)

    Full Text Available ctor, putative / enhancer of shoot regeneration (ESR1) similar to gb|D38124 EREBP-3 from Nicotiana tabacum a...nd contains PF|00847 AP2 domain; identical to cDNA enhancer of shoot regeneration ESR1 GI:18028939, enhancer of shoot regeneration ESR1 [Arabidopsis thaliana] GI:18028940 1e-13 ...

  7. Arabidopsis CDS blastp result: AK241762 [KOME

    Lifescience Database Archive (English)

    Full Text Available ctor, putative / enhancer of shoot regeneration (ESR1) similar to gb|D38124 EREBP-3 from Nicotiana tabacum a...nd contains PF|00847 AP2 domain; identical to cDNA enhancer of shoot regeneration ESR1 GI:18028939, enhancer of shoot regeneration ESR1 [Arabidopsis thaliana] GI:18028940 9e-17 ...

  8. Arabidopsis CDS blastp result: AK242393 [KOME

    Lifescience Database Archive (English)

    Full Text Available ctor, putative / enhancer of shoot regeneration (ESR1) similar to gb|D38124 EREBP-3 from Nicotiana tabacum a...nd contains PF|00847 AP2 domain; identical to cDNA enhancer of shoot regeneration ESR1 GI:18028939, enhancer of shoot regeneration ESR1 [Arabidopsis thaliana] GI:18028940 3e-13 ...

  9. Arabidopsis CDS blastp result: AK242807 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242807 J090060H17 At5g37500.1 68418.m04516 guard cell outward rectifying K+ chann...el (GORK) identical to guard cell outward rectifying K+ channel [Arabidopsis thaliana] gi|11414742|emb|CAC17

  10. Arabidopsis CDS blastp result: AK243408 [KOME

    Lifescience Database Archive (English)

    Full Text Available subunit ClpX, putative similar to CLP protease regulatory subunit CLPX GI:2674203 from [Arabidopsis thaliana]; non-consensus... splice donor GC at exon 4; non-consensus splice donor AA at exon 7 1e-151 ...

  11. Arabidopsis CDS blastp result: AK242797 [KOME

    Lifescience Database Archive (English)

    Full Text Available subunit ClpX, putative similar to CLP protease regulatory subunit CLPX GI:2674203 from [Arabidopsis thaliana]; non-consensus... splice donor GC at exon 4; non-consensus splice donor AA at exon 7 2e-23 ...

  12. Arabidopsis CDS blastp result: AK243408 [KOME

    Lifescience Database Archive (English)

    Full Text Available subunit ClpX, putative similar to CLP protease regulatory subunit CLPX GI:2674203 from [Arabidopsis thaliana]; non-consensus... splice donor GC at exon 4; non-consensus splice donor AA at exon 7 2e-12 ...

  13. Arabidopsis CDS blastp result: AK243428 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK243428 J100067L15 At5g14750.1 68418.m01731 myb family transcription factor (MYB66) / werewolf...iption factor (MYB66) mRNA, partial cds GI:3941491; identical to GP:9755743 myb transcription factor werewolf (WER)/ MYB66 {Arabidopsis thaliana} 8e-36 ...

  14. Arabidopsis CDS blastp result: AK288699 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK288699 J090061C22 At5g14750.1 68418.m01731 myb family transcription factor (MYB66) / werewolf...iption factor (MYB66) mRNA, partial cds GI:3941491; identical to GP:9755743 myb transcription factor werewolf (WER)/ MYB66 {Arabidopsis thaliana} 8e-36 ...

  15. Arabidopsis CDS blastp result: AK243271 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK243271 J100049K04 At5g14750.1 68418.m01731 myb family transcription factor (MYB66) / werewolf...iption factor (MYB66) mRNA, partial cds GI:3941491; identical to GP:9755743 myb transcription factor werewolf (WER)/ MYB66 {Arabidopsis thaliana} 4e-35 ...

  16. Arabidopsis CDS blastp result: AK241812 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK241812 J065210K15 At5g14750.1 68418.m01731 myb family transcription factor (MYB66) / werewolf...iption factor (MYB66) mRNA, partial cds GI:3941491; identical to GP:9755743 myb transcription factor werewolf (WER)/ MYB66 {Arabidopsis thaliana} 1e-22 ...

  17. Arabidopsis CDS blastp result: AK241549 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK241549 J065176M15 At5g14750.1 68418.m01731 myb family transcription factor (MYB66) / werewolf...iption factor (MYB66) mRNA, partial cds GI:3941491; identical to GP:9755743 myb transcription factor werewolf (WER)/ MYB66 {Arabidopsis thaliana} 3e-32 ...

  18. Arabidopsis CDS blastp result: AK241615 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK241615 J065186D02 At5g14750.1 68418.m01731 myb family transcription factor (MYB66) / werewolf...iption factor (MYB66) mRNA, partial cds GI:3941491; identical to GP:9755743 myb transcription factor werewolf (WER)/ MYB66 {Arabidopsis thaliana} 8e-35 ...

  19. Arabidopsis CDS blastp result: AK288487 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK288487 J090040H24 At5g14750.1 68418.m01731 myb family transcription factor (MYB66) / werewolf...iption factor (MYB66) mRNA, partial cds GI:3941491; identical to GP:9755743 myb transcription factor werewolf (WER)/ MYB66 {Arabidopsis thaliana} 5e-37 ...

  20. Arabidopsis CDS blastp result: AK287469 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK287469 J043021L20 At5g14750.1 68418.m01731 myb family transcription factor (MYB66) / werewolf...iption factor (MYB66) mRNA, partial cds GI:3941491; identical to GP:9755743 myb transcription factor werewolf (WER)/ MYB66 {Arabidopsis thaliana} 2e-36 ...

  1. Arabidopsis CDS blastp result: AK241370 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK241370 J065154C10 At5g14750.1 68418.m01731 myb family transcription factor (MYB66) / werewolf...iption factor (MYB66) mRNA, partial cds GI:3941491; identical to GP:9755743 myb transcription factor werewolf (WER)/ MYB66 {Arabidopsis thaliana} 2e-31 ...

  2. Arabidopsis CDS blastp result: AK288415 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK288415 J090031E07 At5g14750.1 68418.m01731 myb family transcription factor (MYB66) / werewolf...iption factor (MYB66) mRNA, partial cds GI:3941491; identical to GP:9755743 myb transcription factor werewolf (WER)/ MYB66 {Arabidopsis thaliana} 3e-37 ...

  3. Arabidopsis CDS blastp result: AK240830 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK240830 J065014C16 At3g12280.1 68416.m01533 retinoblastoma-related protein (RBR1) nearly identical to retin...oblastoma-related protein [Arabidopsis thaliana] GI:8777927; contains Pfam profiles: PF01858 retinoblastoma...-associated protein A domain, PF01857 retinoblastoma-associated protein B domain 0.0 ...

  4. Arabidopsis CDS blastp result: AK121431 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK121431 J023138G19 At3g12280.1 retinoblastoma-related protein (RBR1) nearly identical to retinoblastoma...-related protein [Arabidopsis thaliana] GI:8777927; contains Pfam profiles: PF01858 retinoblastoma...-associated protein A domain, PF01857 retinoblastoma-associated protein B domain 0.0 ...

  5. Arabidopsis CDS blastp result: AK064987 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK064987 J013001D03 At3g12280.1 retinoblastoma-related protein (RBR1) nearly identical to retinoblastoma...-related protein [Arabidopsis thaliana] GI:8777927; contains Pfam profiles: PF01858 retinoblastoma...-associated protein A domain, PF01857 retinoblastoma-associated protein B domain 0.0 ...

  6. Arabidopsis CDS blastp result: AK241627 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK241627 J065187G05 At3g12280.1 68416.m01533 retinoblastoma-related protein (RBR1) nearly identical to retin...oblastoma-related protein [Arabidopsis thaliana] GI:8777927; contains Pfam profiles: PF01858 retinoblastoma...-associated protein A domain, PF01857 retinoblastoma-associated protein B domain 0.0 ...

  7. Arabidopsis CDS blastp result: AK287689 [KOME

    Lifescience Database Archive (English)

    Full Text Available avonol 3-O-methyltransferase 1 / caffeic acid/5-hydroxyferulic acid O-methyltransferase (OMT1) identical to ...1.1.76) (AtOMT1) (Flavonol 3- O-methyltransferase 1) (Caffeic acid/5-hydroxyferulic acid O- methyltransferase) {Arabidopsis thaliana} 5e-23 ...

  8. Arabidopsis CDS blastp result: AK240736 [KOME

    Lifescience Database Archive (English)

    Full Text Available avonol 3-O-methyltransferase 1 / caffeic acid/5-hydroxyferulic acid O-methyltransferase (OMT1) identical to ...1.1.76) (AtOMT1) (Flavonol 3- O-methyltransferase 1) (Caffeic acid/5-hydroxyferulic acid O- methyltransferase) {Arabidopsis thaliana} 1e-22 ...

  9. Arabidopsis CDS blastp result: AK241705 [KOME

    Lifescience Database Archive (English)

    Full Text Available avonol 3-O-methyltransferase 1 / caffeic acid/5-hydroxyferulic acid O-methyltransferase (OMT1) identical to ...1.1.76) (AtOMT1) (Flavonol 3- O-methyltransferase 1) (Caffeic acid/5-hydroxyferulic acid O- methyltransferase) {Arabidopsis thaliana} 1e-11 ...

  10. Arabidopsis CDS blastp result: AK287483 [KOME

    Lifescience Database Archive (English)

    Full Text Available avonol 3-O-methyltransferase 1 / caffeic acid/5-hydroxyferulic acid O-methyltransferase (OMT1) identical to ...1.1.76) (AtOMT1) (Flavonol 3- O-methyltransferase 1) (Caffeic acid/5-hydroxyferulic acid O- methyltransferase) {Arabidopsis thaliana} 1e-37 ...

  11. Arabidopsis CDS blastp result: AK242290 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242290 J075191E07 At4g13870.2 68417.m02149 Werner Syndrome-like exonuclease (WEX)... contains Pfam profile PF01612: 3'-5' exonuclease; identical to Werner Syndrome-like exonuclease [Arabidopsis thaliana] GP:28195109 gb:AAO33765 1e-20 ...

  12. Arabidopsis CDS blastp result: AK063585 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK063585 001-118-A04 At4g13870.2 Werner Syndrome-like exonuclease (WEX) contains Pf...am profile PF01612: 3'-5' exonuclease; identical to Werner Syndrome-like exonuclease [Arabidopsis thaliana] GP:28195109 gb:AAO33765 6e-16 ...

  13. Arabidopsis CDS blastp result: AK242290 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242290 J075191E07 At4g13870.1 68417.m02148 Werner Syndrome-like exonuclease (WEX)... contains Pfam profile PF01612: 3'-5' exonuclease; identical to Werner Syndrome-like exonuclease [Arabidopsis thaliana] GP:28195109 gb:AAO33765 1e-20 ...

  14. Arabidopsis CDS blastp result: AK072218 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK072218 J013167O21 At1g55350.4 calpain-type cysteine protease family identical to calpain...-like protein GI:20268660 from [Arabidopsis thaliana]; contains Pfam profiles: PF00648 Calpain family... cysteine protease, PF01067 Calpain large subunit,domain III; identical to cDNA calpain-like protein GI:20268659 1e-150 ...

  15. Arabidopsis CDS blastp result: AK287576 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK287576 J065037D19 At1g28300.1 68414.m03473 transcriptional factor B3 family protein / leaf...y cotyledon 2 (LEC2) nearly identical to LEAFY COTYLEDON 2 [Arabidopsis thaliana] GI:15987516; contains Pfam profile PF02362: B3 DNA binding domain 5e-13 ...

  16. Arabidopsis CDS blastp result: AK243493 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK243493 J100074A10 At2g23380.1 68415.m02792 curly leaf protein (CURLY LEAF) / poly...comb-group protein identical to polycomb group [Arabidopsis thaliana] GI:1903019 (curly leaf); contains Pfam profile PF00856: SET domain 0.0 ...

  17. Arabidopsis CDS blastp result: AK111743 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK111743 J023052J10 At2g23380.1 curly leaf protein (CURLY LEAF) / polycomb-group pr...otein identical to polycomb group [Arabidopsis thaliana] GI:1903019 (curly leaf); contains Pfam profile PF00856: SET domain 3e-22 ...

  18. Arabidopsis CDS blastp result: AK242890 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242890 J090079L19 At5g16910.1 68418.m01982 cellulose synthase family protein similar to gi:2827143 cellulo...se synthase catalytic subunit, Arabidopsis thaliana, gi:9622886 cellulose synthase-7 from Zea mays 1e-130 ...

  19. Arabidopsis CDS blastp result: AK242585 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242585 J090010M20 At5g16910.1 68418.m01982 cellulose synthase family protein similar to gi:2827143 cellulo...se synthase catalytic subunit, Arabidopsis thaliana, gi:9622886 cellulose synthase-7 from Zea mays 2e-65 ...

  20. Arabidopsis CDS blastp result: AK110534 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK110534 002-168-A07 At5g16910.1 cellulose synthase family protein similar to gi:2827143 cellulose... synthase catalytic subunit, Arabidopsis thaliana, gi:9622886 cellulose synthase-7 from Zea mays 1e-114 ...

  1. Arabidopsis CDS blastp result: AK242585 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242585 J090010M20 At1g32180.1 68414.m03958 cellulose synthase family protein similar to cellulose... synthase catalytic subunit gi:2827143 from [Arabidopsis thaliana], cellulose synthase-9 (gi:9622890) from Zea mays 1e-24 ...

  2. Arabidopsis CDS blastp result: AK242601 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242601 J090014G03 At5g16910.1 68418.m01982 cellulose synthase family protein similar to gi:2827143 cellulo...se synthase catalytic subunit, Arabidopsis thaliana, gi:9622886 cellulose synthase-7 from Zea mays 0.0 ...

  3. Arabidopsis CDS blastp result: AK242601 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242601 J090014G03 At2g32540.1 68415.m03975 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 2e-45 ...

  4. Arabidopsis CDS blastp result: AK242585 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242585 J090010M20 At1g32180.1 68414.m03958 cellulose synthase family protein similar to cellulose... synthase catalytic subunit gi:2827143 from [Arabidopsis thaliana], cellulose synthase-9 (gi:9622890) from Zea mays 3e-66 ...

  5. Arabidopsis CDS blastp result: AK069071 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK069071 J023010H01 At2g32540.1 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 1e-167 ...

  6. Arabidopsis CDS blastp result: AK242585 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242585 J090010M20 At4g23990.1 68417.m03448 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 1e-124 ...

  7. Arabidopsis CDS blastp result: AK060286 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK060286 001-006-C08 At2g32540.1 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 6e-78 ...

  8. Arabidopsis CDS blastp result: AK242601 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242601 J090014G03 At4g38190.1 68417.m05391 cellulose synthase family protein similar to cellulose... synthase catalytic subunit gi:2827143 from [Arabidopsis thaliana], cellulose synthase-5 (gi:9622882) from Zea mays 0.0 ...

  9. Arabidopsis CDS blastp result: AK242601 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242601 J090014G03 At2g32530.1 68415.m03974 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 2e-29 ...

  10. Arabidopsis CDS blastp result: AK242601 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242601 J090014G03 At4g23990.1 68417.m03448 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 5e-25 ...

  11. Arabidopsis CDS blastp result: AK242585 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242585 J090010M20 At5g16910.1 68418.m01982 cellulose synthase family protein similar to gi:2827143 cellulo...se synthase catalytic subunit, Arabidopsis thaliana, gi:9622886 cellulose synthase-7 from Zea mays 1e-28 ...

  12. Arabidopsis CDS blastp result: AK105393 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK105393 001-123-B04 At5g16910.1 cellulose synthase family protein similar to gi:2827143 cellulose... synthase catalytic subunit, Arabidopsis thaliana, gi:9622886 cellulose synthase-7 from Zea mays 0.0 ...

  13. Arabidopsis CDS blastp result: AK242601 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242601 J090014G03 At4g23990.1 68417.m03448 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 8e-25 ...

  14. Arabidopsis CDS blastp result: AK242890 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242890 J090079L19 At1g32180.1 68414.m03958 cellulose synthase family protein similar to cellulose... synthase catalytic subunit gi:2827143 from [Arabidopsis thaliana], cellulose synthase-9 (gi:9622890) from Zea mays 1e-126 ...

  15. Arabidopsis CDS blastp result: AK242585 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242585 J090010M20 At4g38190.1 68417.m05391 cellulose synthase family protein similar to cellulose... synthase catalytic subunit gi:2827143 from [Arabidopsis thaliana], cellulose synthase-5 (gi:9622882) from Zea mays 8e-63 ...

  16. Arabidopsis CDS blastp result: AK242890 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242890 J090079L19 At4g38190.1 68417.m05391 cellulose synthase family protein similar to cellulose... synthase catalytic subunit gi:2827143 from [Arabidopsis thaliana], cellulose synthase-5 (gi:9622882) from Zea mays 1e-125 ...

  17. Arabidopsis CDS blastp result: AK242601 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242601 J090014G03 At1g32180.1 68414.m03958 cellulose synthase family protein similar to cellulose... synthase catalytic subunit gi:2827143 from [Arabidopsis thaliana], cellulose synthase-9 (gi:9622890) from Zea mays 0.0 ...

  18. Arabidopsis CDS blastp result: AK242601 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242601 J090014G03 At4g23990.1 68417.m03448 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 2e-26 ...

  19. Arabidopsis CDS blastp result: AK242890 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242890 J090079L19 At2g32540.1 68415.m03975 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 4e-47 ...

  20. Arabidopsis CDS blastp result: AK242585 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242585 J090010M20 At2g32540.1 68415.m03975 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 4e-98 ...

  1. Arabidopsis CDS blastp result: AK242585 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242585 J090010M20 At2g32530.1 68415.m03974 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 8e-98 ...

  2. Arabidopsis CDS blastp result: AK109812 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK109812 002-147-H02 At5g16910.1 cellulose synthase family protein similar to gi:2827143 cellulose... synthase catalytic subunit, Arabidopsis thaliana, gi:9622886 cellulose synthase-7 from Zea mays 5e-90 ...

  3. Arabidopsis CDS blastp result: AK242601 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242601 J090014G03 At2g32540.1 68415.m03975 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 3e-31 ...

  4. Arabidopsis CDS blastp result: AK121003 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK121003 J023045B21 At2g32540.1 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 1e-167 ...

  5. Arabidopsis CDS blastp result: AK242601 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242601 J090014G03 At2g32530.1 68415.m03974 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 5e-48 ...

  6. Arabidopsis CDS blastp result: AK242890 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242890 J090079L19 At4g23990.1 68417.m03448 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 1e-45 ...

  7. Arabidopsis CDS blastp result: AK242585 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242585 J090010M20 At4g38190.1 68417.m05391 cellulose synthase family protein similar to cellulose... synthase catalytic subunit gi:2827143 from [Arabidopsis thaliana], cellulose synthase-5 (gi:9622882) from Zea mays 4e-27 ...

  8. Arabidopsis CDS blastp result: AK061162 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK061162 006-209-A01 At2g32540.1 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 3e-35 ...

  9. Arabidopsis CDS blastp result: AK242890 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242890 J090079L19 At2g32530.1 68415.m03974 cellulose synthase family protein similar to cellulose... synthase catalytic subunit from Arabidopsis thaliana [gi:5230423], cellulose synthase-5 from Zea mays [gi:9622882] 4e-50 ...

  10. Arabidopsis CDS blastp result: AK119521 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK119521 001-202-D09 At3g57050.2 cystathionine beta-lyase, chloroplast / beta-cystathionase...thionase) (Cysteine lyase) {Arabidopsis thaliana} 1e-173 ... ... / cysteine lyase (CBL) identical to SP|P53780 Cystathionine beta-lyase, chloroplast precursor (EC 4.4.1.8) (CBL) (Beta-cysta

  11. Arabidopsis CDS blastp result: AK108403 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK108403 002-142-G06 At3g57050.2 cystathionine beta-lyase, chloroplast / beta-cystathionase...thionase) (Cysteine lyase) {Arabidopsis thaliana} 5e-36 ... ... / cysteine lyase (CBL) identical to SP|P53780 Cystathionine beta-lyase, chloroplast precursor (EC 4.4.1.8) (CBL) (Beta-cysta

  12. Arabidopsis CDS blastp result: AK241330 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK241330 J065144B19 At3g29410.1 68416.m03695 terpene synthase/cyclase family protein similar to terpene... synthase GB:CAA72074 from [Arabidopsis thaliana], contains Pfam profile: PF01397 terpene synthase family 5e-64 ...

  13. Arabidopsis CDS blastp result: AK242212 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242212 J075171E13 At3g29410.1 68416.m03695 terpene synthase/cyclase family protein similar to terpene... synthase GB:CAA72074 from [Arabidopsis thaliana], contains Pfam profile: PF01397 terpene synthase family 1e-21 ...

  14. Arabidopsis CDS blastp result: AK241679 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK241679 J065193F24 At3g29410.1 68416.m03695 terpene synthase/cyclase family protein similar to terpene... synthase GB:CAA72074 from [Arabidopsis thaliana], contains Pfam profile: PF01397 terpene synthase family 5e-65 ...

  15. Arabidopsis CDS blastp result: AK105299 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK105299 001-116-H10 At1g72660.1 developmentally regulated GTP-binding protein, put...ative very strong similarity to developmentally regulated GTP binding protein (DRG1) [Arabidopsis thaliana] GI:2345150 0.0 ...

  16. Arabidopsis CDS blastp result: AK111540 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK111540 J013037H01 At1g72660.1 developmentally regulated GTP-binding protein, puta...tive very strong similarity to developmentally regulated GTP binding protein (DRG1) [Arabidopsis thaliana] GI:2345150 0.0 ...

  17. Arabidopsis CDS blastp result: AK240892 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK240892 J065030K10 At4g36920.1 68417.m05233 floral homeotic protein APETALA2 (AP2)... Identical to (SP:P47927) Floral homeotic protein APETALA2. [Mouse-ear cress] {Arabidopsis thaliana} 2e-41 ...

  18. Arabidopsis CDS blastp result: AK287726 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK287726 J065138E17 At4g36920.1 68417.m05233 floral homeotic protein APETALA2 (AP2)... Identical to (SP:P47927) Floral homeotic protein APETALA2. [Mouse-ear cress] {Arabidopsis thaliana} 1e-41 ...

  19. Arabidopsis CDS blastp result: AK242211 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242211 J075171C16 At1g69120.1 68414.m07909 floral homeotic protein APETALA1 (AP1)... / agamous-like MADS box protein (AGL7) identical to SP|P35631 Floral homeotic protein APETALA1 (AGL7 protein) {Arabidopsis thaliana} 8e-22 ...

  20. Arabidopsis CDS blastp result: AK242387 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242387 J080051E14 At4g36920.1 68417.m05233 floral homeotic protein APETALA2 (AP2)... Identical to (SP:P47927) Floral homeotic protein APETALA2. [Mouse-ear cress] {Arabidopsis thaliana} 3e-27 ...