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Whole-Plant Growth Stage Ontology for Angiosperms and Its Application in Plant Biology1[OA]

Pujar, Anuradha; Jaiswal, Pankaj; Kellogg, Elizabeth A.; Ilic, Katica; Vincent, Leszek; Avraham, Shulamit; Stevens, Peter; Zapata, Felipe; Reiser, Leonore; Rhee, Seung Y.; Sachs, Martin M.; Schaeffer, Mary; Stein, Lincoln; Ware, Doreen; McCouch, Susan
Fonte: American Society of Plant Biologists Publicador: American Society of Plant Biologists
Tipo: Artigo de Revista Científica
Publicado em /10/2006 Português
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45.92%
Plant growth stages are identified as distinct morphological landmarks in a continuous developmental process. The terms describing these developmental stages record the morphological appearance of the plant at a specific point in its life cycle. The widely differing morphology of plant species consequently gave rise to heterogeneous vocabularies describing growth and development. Each species or family specific community developed distinct terminologies for describing whole-plant growth stages. This semantic heterogeneity made it impossible to use growth stage description contained within plant biology databases to make meaningful computational comparisons. The Plant Ontology Consortium (http://www.plantontology.org) was founded to develop standard ontologies describing plant anatomical as well as growth and developmental stages that can be used for annotation of gene expression patterns and phenotypes of all flowering plants. In this article, we describe the development of a generic whole-plant growth stage ontology that describes the spatiotemporal stages of plant growth as a set of landmark events that progress from germination to senescence. This ontology represents a synthesis and integration of terms and concepts from a variety of species-specific vocabularies previously used for describing phenotypes and genomic information. It provides a common platform for annotating gene function and gene expression in relation to the developmental trajectory of a plant described at the organismal level. As proof of concept the Plant Ontology Consortium used the plant ontology growth stage ontology to annotate genes and phenotypes in plants with initial emphasis on those represented in The Arabidopsis Information Resource...

A Conserved Threonine Residue in the Juxtamembrane Domain of the XA21 Pattern Recognition Receptor Is Critical for Kinase Autophosphorylation and XA21-mediated Immunity*

Chen, Xuewei; Chern, Mawsheng; Canlas, Patrick E.; Jiang, Caiying; Ruan, Deling; Cao, Peijian; Ronald, Pamela C.
Fonte: American Society for Biochemistry and Molecular Biology Publicador: American Society for Biochemistry and Molecular Biology
Tipo: Artigo de Revista Científica
Português
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Despite the key role that pattern recognition receptors (PRRs) play in regulating immunity in plants and animals, the mechanism of activation of the associated non-arginine-aspartate (non-RD) kinases is unknown. The rice PRR XA21 recognizes the pathogen-associated molecular pattern, Ax21 (activator of XA21-mediated immunity). Here we show that the XA21 juxtamembrane (JM) domain is required for kinase autophosphorylation. Threonine 705 in the XA21 JM domain is essential for XA21 autophosphorylation in vitro and XA21-mediated innate immunity in vivo. The replacement of Thr705 by an alanine or glutamic acid abolishes XA21 autophosphorylation and eliminates interactions between XA21 and four XA21-binding proteins in yeast and rice. Although threonine residues analogous to Thr705 of XA21 are present in the JM domains of most RD and non-RD plant receptor-like kinases, this residue is not required for autophosphorylation of the Arabidopsis RD RLK BRI1 (brassinosteroid insensitive 1). The threonine 705 of XA21 is conserved only in the JM domains of plant RLKs but not in those of fly, human, or mouse suggesting distinct regulatory mechanisms. These results contribute to growing knowledge regarding the mechanism by which non-RD RLKs function in plant.

Arabidopsis AtSerpin1, Crystal Structure and in Vivo Interaction with Its Target Protease RESPONSIVE TO DESICCATION-21 (RD21)*

Lampl, Nardy; Budai-Hadrian, Ofra; Davydov, Olga; Joss, Tom V.; Harrop, Stephen J.; Curmi, Paul M. G.; Roberts, Thomas H.; Fluhr, Robert
Fonte: American Society for Biochemistry and Molecular Biology Publicador: American Society for Biochemistry and Molecular Biology
Tipo: Artigo de Revista Científica
Português
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45.93%
In animals, protease inhibitors of the serpin family are associated with many physiological processes, including blood coagulation and innate immunity. Serpins feature a reactive center loop (RCL), which displays a protease target sequence as a bait. RCL cleavage results in an irreversible, covalent serpin-protease complex. AtSerpin1 is an Arabidopsis protease inhibitor that is expressed ubiquitously throughout the plant. The x-ray crystal structure of recombinant AtSerpin1 in its native stressed conformation was determined at 2.2 Å. The electrostatic surface potential below the RCL was found to be highly positive, whereas the breach region critical for RCL insertion is an unusually open structure. AtSerpin1 accumulates in plants as a full-length and a cleaved form. Fractionation of seedling extracts by nonreducing SDS-PAGE revealed the presence of an additional slower migrating complex that was absent when leaves were treated with the specific cysteine protease inhibitor l-trans-epoxysuccinyl-l-leucylamido (4-guanidino)butane. Significantly, RESPONSIVE TO DESICCATION-21 (RD21) was the major protease labeled with the l-trans-epoxysuccinyl-l-leucylamido (4-guanidino)butane derivative DCG-04 in wild type extracts but not in extracts of mutant plants constitutively overexpressing AtSerpin1...

Reverse Genetic Screening Identifies Five E-class PPR Proteins Involved in RNA Editing in Mitochondria of Arabidopsis thaliana*

Takenaka, Mizuki; Verbitskiy, Daniil; Zehrmann, Anja; Brennicke, Axel
Fonte: American Society for Biochemistry and Molecular Biology Publicador: American Society for Biochemistry and Molecular Biology
Tipo: Artigo de Revista Científica
Português
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45.95%
RNA editing in flowering plant mitochondria post-transcriptionally alters several hundred nucleotides from C to U, mostly in mRNAs. Several factors required for specific RNA-editing events in plant mitochondria and plastids have been identified, all of them PPR proteins of the PLS subclass with a C-terminal E-domain and about half also with an additional DYW domain. Based on this information, we here probe the connection between E-PPR proteins and RNA editing in plant mitochondria. We initiated a reverse genetics screen of T-DNA insertion lines in Arabidopsis thaliana and investigated 58 of the 150 E-PPR-coding genes for a function in RNA editing. Six genes were identified to be involved in mitochondrial RNA editing at specific sites. Homozygous mutants of the five genes MEF18-MEF22 display no gross disturbance in their growth or development patterns, suggesting that the editing sites affected are not crucial at least in the greenhouse. These results show that a considerable percentage of the E-PPR proteins are involved in the functional processing of site-specific RNA editing in plant mitochondria.

A Small GTPase Activator Protein Interacts with Cytoplasmic Phytochromes in Regulating Root Development*

Shin, Dong Ho; Cho, Man-Ho; Kim, Tae-Lim; Yoo, Jihye; Kim, Jeong-Il; Han, Yun-Jeong; Song, Pill-Soon; Jeon, Jong-Seong; Bhoo, Seong Hee; Hahn, Tae-Ryong
Fonte: American Society for Biochemistry and Molecular Biology Publicador: American Society for Biochemistry and Molecular Biology
Tipo: Artigo de Revista Científica
Português
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Phytochromes enable plants to sense light information and regulate developmental responses. Phytochromes interact with partner proteins to transmit light signals to downstream components for plant development. PIRF1 (phytochrome-interacting ROP guanine-nucleotide exchange factor (RopGEF 1)) functions as a light-signaling switch regulating root development through the activation of ROPs (Rho-like GTPase of plant) in the cytoplasm. In vitro pulldown and yeast two-hybrid assays confirmed the interaction between PIRF1 and phytochromes. PIRF1 interacted with the N-terminal domain of phytochromes through its conserved PRONE (plant-specific ROP nucleotide exchanger) region. PIRF1 also interacted with ROPs and activated them in a phytochrome-dependent manner. The Pr form of phytochrome A enhanced the RopGEF activity of PIRF1, whereas the Pfr form inhibited it. A bimolecular fluorescence complementation analysis demonstrated that PIRF1 was localized in the cytoplasm and bound to the phytochromes in darkness but not in light. PIRF1 loss of function mutants (pirf1) of Arabidopsis thaliana showed a longer root phenotype in the dark. In addition, both PIRF1 overexpression mutants (PIRF1-OX) and phytochrome-null mutants (phyA-211 and phyB-9) showed retarded root elongation and irregular root hair formation...

Microsatellite Instability in Arabidopsis Increases with Plant Development1[W][OA]

Golubov, Andrey; Yao, Youli; Maheshwari, Priti; Bilichak, Andriy; Boyko, Alex; Belzile, François; Kovalchuk, Igor
Fonte: American Society of Plant Biologists Publicador: American Society of Plant Biologists
Tipo: Artigo de Revista Científica
Português
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Plant development consists of the initial phase of intensive cell division followed by continuous genome endoreduplication, cell growth, and elongation. The maintenance of genome stability under these conditions is the main task performed by DNA repair and genome surveillance mechanisms. Our previous work showed that the rate of homologous recombination repair in older plants decreases. We hypothesized that this age-dependent decrease in the recombination rate is paralleled with other changes in DNA repair capacity. Here, we analyzed microsatellite stability using transgenic Arabidopsis (Arabidopsis thaliana) plants that carry the nonfunctional β-glucuronidase gene disrupted by microsatellite repeats. We found that microsatellite instability increased dramatically with plant age. We analyzed the contribution of various mechanisms to microsatellite instability, including replication errors and mistakes of DNA repair mechanisms such as mismatch repair, excision repair, and strand break repair. Analysis of total DNA polymerase activity using partially purified protein extracts showed an age-dependent decrease in activity and an increase in fidelity. Analysis of the steady-state RNA level of DNA replicative polymerases α, δ, Pol I-like A...

Discovery and Characterization of Novel Cyclotides Originated from Chimeric Precursors Consisting of Albumin-1 Chain a and Cyclotide Domains in the Fabaceae Family*

Nguyen, Giang Kien Truc; Zhang, Sen; Nguyen, Ngan Thi Kim; Nguyen, Phuong Quoc Thuc; Chiu, Ming Sheau; Hardjojo, Antony; Tam, James P.
Fonte: American Society for Biochemistry and Molecular Biology Publicador: American Society for Biochemistry and Molecular Biology
Tipo: Artigo de Revista Científica
Português
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The tropical plant Clitoria ternatea is a member of the Fabaceae family well known for its medicinal values. Heat extraction of C. ternatea revealed that the bioactive fractions contained heat-stable cysteine-rich peptides (CRPs). The CRP family of A1b (Albumin-1 chain b/leginsulins), which is a linear cystine knot CRP, has been shown to present abundantly in the Fabaceae. In contrast, the cyclotide family, which also belongs to the cystine knot CRPs but with a cyclic structure, is commonly found in the Rubiaceae, Violaceae, and Cucurbitaceae families. In this study, we report the discovery of a panel of 15 heat-stable CRPs, of which 12 sequences (cliotide T1–T12) are novel. We show unambiguously that the cliotides are cyclotides and not A1bs, as determined by their sequence homology, disulfide connectivity, and membrane active properties indicated by their antimicrobial activities against Escherichia coli and cytotoxicities to HeLa cells. We also show that cliotides are prevalent in C. ternatea and are found in every plant tissue examined, including flowers, seeds, and nodules. In addition, we demonstrate that their precursors are chimeras, half from cyclotide and the other half from Albumin-1, with the cyclotide domain displacing the A1b domain in the precursor. Their chimeric structures likely originate from either horizontal gene transfer or convergent evolution in plant nuclear genomes...

Comprehensive Compositional Analysis of Plant Cell Walls (Lignocellulosic biomass) Part II: Carbohydrates

Foster, Cliff E.; Martin, Tina M.; Pauly, Markus
Fonte: MyJove Corporation Publicador: MyJove Corporation
Tipo: Artigo de Revista Científica
Publicado em 12/03/2010 Português
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45.9%
The need for renewable, carbon neutral, and sustainable raw materials for industry and society has become one of the most pressing issues for the 21st century. This has rekindled interest in the use of plant products as industrial raw materials for the production of liquid fuels for transportation2 and other products such as biocomposite materials6. Plant biomass remains one of the greatest untapped reserves on the planet4. It is mostly comprised of cell walls that are composed of energy rich polymers including cellulose, various hemicelluloses, and the polyphenol lignin5 and thus sometimes termed lignocellulosics. However, plant cell walls have evolved to be recalcitrant to degradation as walls contribute extensively to the strength and structural integrity of the entire plant. Despite its necessary rigidity, the cell wall is a highly dynamic entity that is metabolically active and plays crucial roles in numerous cell activities such as plant growth and differentiation5. Due to the various functions of walls, there is an immense structural diversity within the walls of different plant species and cell types within a single plant4. Hence, depending of what crop species, crop variety, or plant tissue is used for a biorefinery, the processing steps for depolymerisation by chemical/enzymatic processes and subsequent fermentation of the various sugars to liquid biofuels need to be adjusted and optimized. This fact underpins the need for a thorough characterization of plant biomass feedstocks. Here we describe a comprehensive analytical methodology that enables the determination of the composition of lignocellulosics and is amenable to a medium to high-throughput analysis (Figure 1). The method starts of with preparing destarched cell wall material. The resulting lignocellulosics are then split up to determine its monosaccharide composition of the hemicelluloses and other matrix polysaccharides1...

Targeted Systems Biology Profiling of Tomato Fruit Reveals Coordination of the Yang Cycle and a Distinct Regulation of Ethylene Biosynthesis during Postclimacteric Ripening1[C][W][OA]

Van de Poel, Bram; Bulens, Inge; Markoula, Aikaterina; Hertog, Maarten L.A.T.M.; Dreesen, Rozemarijn; Wirtz, Markus; Vandoninck, Sandy; Oppermann, Yasmin; Keulemans, Johan; Hell, Ruediger; Waelkens, Etienne; De Proft, Maurice P.; Sauter, Margret; Nicolai,
Fonte: American Society of Plant Biologists Publicador: American Society of Plant Biologists
Tipo: Artigo de Revista Científica
Português
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The concept of system 1 and system 2 ethylene biosynthesis during climacteric fruit ripening was initially described four decades ago. Although much is known about fruit development and climacteric ripening, little information is available about how ethylene biosynthesis is regulated during the postclimacteric phase. A targeted systems biology approach revealed a novel regulatory mechanism of ethylene biosynthesis of tomato (Solanum lycopersicum) when fruit have reached their maximal ethylene production level and which is characterized by a decline in ethylene biosynthesis. Ethylene production is shut down at the level of 1-aminocyclopropane-1-carboxylic acid oxidase. At the same time, 1-aminocyclopropane-1-carboxylic acid synthase activity increases. Analysis of the Yang cycle showed that the Yang cycle genes are regulated in a coordinated way and are highly expressed during postclimacteric ripening. Postclimacteric red tomatoes on the plant showed only a moderate regulation of 1-aminocyclopropane-1-carboxylic acid synthase and Yang cycle genes compared with the regulation in detached fruit. Treatment of red fruit with 1-methylcyclopropane and ethephon revealed that the shut-down mechanism in ethylene biosynthesis is developmentally programmed and only moderately ethylene sensitive. We propose that the termination of autocatalytic ethylene biosynthesis of system 2 in ripe fruit delays senescence and preserves the fruit until seed dispersal.

Medicinal Plants: Past, Present and Future

Fonte: American Society of Plant Biologists Publicador: American Society of Plant Biologists
Tipo: Artigo de Revista Científica
Publicado em /01/2013 Português
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(with Jane Ellis) - Plants produce thousands of specialized metabolites, many of which have medicinal uses. More than half of the top 150 prescribed drugs in the US have at least one compound derived from plants, and about 80% of the worlds population depends on plants or plant extracts as a major source of healthcare. This lecture looks at the history of medicinal plants, herbal remedies in traditional and contemporary medicine, and ongoing efforts to identify novel medicinal compounds from plants. New approaches, such as metabolomics, metabolic engineering and systems and synthetic biology, are contributing towards the identification, characterization and production of plant-derived medicines.

Catalyzing plant science research with RNA-seq

Martin, Laetitia B. B.; Fei, Zhangjun; Giovannoni, James J.; Rose, Jocelyn K. C.
Fonte: Frontiers Media S.A. Publicador: Frontiers Media S.A.
Tipo: Artigo de Revista Científica
Publicado em 01/04/2013 Português
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45.93%
Next generation DNA sequencing technologies are driving increasingly rapid, affordable and high resolution analyses of plant transcriptomes through sequencing of their associated cDNA (complementary DNA) populations; an analytical platform commonly referred to as RNA-sequencing (RNA-seq). Since entering the arena of whole genome profiling technologies only a few years ago, RNA-seq has proven itself to be a powerful tool with a remarkably diverse range of applications, from detailed studies of biological processes at the cell type-specific level, to providing insights into fundamental questions in plant biology on an evolutionary time scale. Applications include generating genomic data for heretofore unsequenced species, thus expanding the boundaries of what had been considered “model organisms,” elucidating structural and regulatory gene networks, revealing how plants respond to developmental cues and their environment, allowing a better understanding of the relationships between genes and their products, and uniting the “omics” fields of transcriptomics, proteomics, and metabolomics into a now common systems biology paradigm. We provide an overview of the breadth of such studies and summarize the range of RNA-seq protocols that have been developed to address questions spanning cell type-specific-based transcriptomics...

The Potential of Text Mining in Data Integration and Network Biology for Plant Research: A Case Study on Arabidopsis[C][W]

Van Landeghem, Sofie; De Bodt, Stefanie; Drebert, Zuzanna J.; Inzé, Dirk; Van de Peer, Yves
Fonte: American Society of Plant Biologists Publicador: American Society of Plant Biologists
Tipo: Artigo de Revista Científica
Português
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Manual evaluation of state-of-the art text mining data reveals promising results for its application in plant network biology. Focusing on Arabidopsis thaliana, an integrated network of text mining and experimental data highlights the complementarity of these resources and the necessity for text mining tools to uncover the latest relevant findings from the literature.

Plant chemical biology: are we meeting the promise?

Hicks, Glenn R.; Raikhel, Natasha V.
Fonte: Frontiers Media S.A. Publicador: Frontiers Media S.A.
Tipo: Artigo de Revista Científica
Publicado em 08/09/2014 Português
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45.93%
As an early adopter of plant chemical genetics to the study of endomembrane trafficking, we have observed the growth of small molecule approaches. Within the field, we often describe the strengths of the approach in a broad, generic manner, such as the ability to address redundancy and lethality. But, we are now in a much better position to evaluate the demonstrated value of the approach based on examples. In this perspective, we offer an assessment of chemical genetics in plants and where its applications may be of particular utility from the perspective of the cell biologist. Beyond this, we suggest areas to be addressed to provide broader access and enhance the effectiveness of small molecule approaches in plant biology.

EU-OPENSCREEN—chemical tools for the study of plant biology and resistance mechanisms

Meiners, Torsten; Stechmann, Bahne; Frank, Ronald
Fonte: Springer Berlin Heidelberg Publicador: Springer Berlin Heidelberg
Tipo: Artigo de Revista Científica
Publicado em 31/07/2014 Português
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EU-OPENSCREEN is an academic research infrastructure initiative in Europe for enabling researchers in all life sciences to take advantage of chemical biology approaches to their projects. In a collaborative effort of national networks in 16 European countries, EU-OPENSCREEN will develop novel chemical compounds with external users to address questions in, among other fields, systems and network biology (directed and selective perturbation of signalling pathways), structural biology (compound-target interactions at atomic resolution), pharmacology (early drug discovery and toxicology) and plant biology (response of wild or crop plants to environmental and agricultural substances). EU-OPENSCREEN supports all stages of a tool development project, including assay adaptation, high-throughput screening and chemical optimisation of the ‘hit’ compounds. All tool compounds and data will be made available to the scientific community. EU-OPENSCREEN integrates high-capacity screening platforms throughout Europe, which share a rationally selected compound collection comprising up to 300,000 (commercial and proprietary compounds collected from European chemists). By testing systematically this chemical collection in hundreds of assays originating from very different biological themes...

The ecology, biology and conservation of threatened Phebalium species in South Australia

Jusaitis, M.
Fonte: Plant Biodiversity Centre, State Herbarium of South Australia Publicador: Plant Biodiversity Centre, State Herbarium of South Australia
Tipo: Livro
Publicado em //2000 Português
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Five species of Phebalium occurring in South Australia (P. brachyphyllum, P. equestre, P. hillebrandii, P. glandulosum subsp. glandulosum and P. lowanense) have various categories of threat ranging from Endangered to Rare. Three are endemic to South Australia, and all have rather limited, and in some cases declining areas of occupancy. This study was undertaken to develop an understanding of the biology and ecology of these Phebaliums in relation to their conservation. Current population details, habitat requirements and threats were documented. Field sites were established for collection of demographic and phenological information on each species. Reproductive biology, seed dispersal mechanisms, and recruitment were studied, and ecological factors that affect sensitive life history stages (eg, weeds, grazing, fire, disturbance) were examined. Techniques for propagation of each species of Phebalium were developed using seed, cuttings and/or micropropagation. Two species (P. equestre and P. glandulosum) were successfully translocated into conservation reserves to increase their areas of occupancy. Management recommendations were made for each species to aid development of recovery guidelines.; Jusaitis, Manfred

The evolutionary biology of pollination: studies in a genus of australian sexually deceptive orchids

Whitehead, Michael Robert
Fonte: Universidade Nacional da Austrália Publicador: Universidade Nacional da Austrália
Tipo: Thesis (PhD); Doctor of Philosophy (PhD)
Português
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There are few other structures in nature from which evolution has generated such wide diversity as the flower or inflorescence, and this diversity is commonly attributed to the influence of their animal visitors. By outsourcing their mate choice to pollinators, plants have left themselves - and especially their flowers - subject to the selective forces imposed by the behaviour, cognition and perception of the pollinators that serve them. The orchids provide some of the most remarkable and extreme examples of adaptations to specific animal pollinators. Perhaps one of the most peculiar of these strategies is sexual deception, whereby male insects are lured to the flower by mimicry of the female sex pheromone. This seemingly unlikely strategy has evolved multiple times independently on different continents in different parts of the orchid phylogeny which raises the question of what adaptive advantages might underlie such a strategy. This multidisciplinary thesis studies gene flow and pollinator behaviour in two sympatric sexually deceptive orchids in the genus Chiloglottis. The two species attract their specific wasp pollinators through emission of distinct species - specific semiochemicals. Since floral volatiles play a pre-eminent role in pollinator attraction...

Reversal of an immunity associated plant cell death program by the growth regulator auxin

Suresh Gopalan
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Português
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45.93%
One form of plant immunity against pathogens involves a rapid host programmed cell death at the site of infection accompanied by resistance, termed the hypersensitive response (HR). Here it is shown that the HR programmed cell death program initiated by the bacterial type III secretion system dependent proteinaceous elicitor harpin from Erwinia amylovora can be reversed till very late in the process by the plant growth regulator auxin. Early inhibition or late reversal of this cell death program does not affect marker genes tightly correlated with local and systemic resistance. Cross-regulation between cell death programs and growth regulators is prevalent in different kingdoms. Thus, the concept that cell death program can be reversed till late provides a framework for further investigation of such phenomena, in addition to having utility in choosing better targets and strategies for treating mammalian and agricultural diseases.

GreenPhylDB: A Gene Family Database for plant functional Genomics

Matthieu G. Conte; Marie-Angélique Laporte; Christophe Périn; Mathieu Rouard
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Poster
Português
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With the increasing number of genomes being sequenced, a major objective is to transfer accurate annotation from characterised proteins to uncharacterised sequences. Consequently, comparative genomics has become a usual and efficient strategy in functional genomics. The release of various annotated genomes of plants, such as _O. sativa_ and _A. thaliana_, has allowed setting up comprehensive lists of gene families defined by automated methods. However, like for gene sequence, manual curation of gene families is an important requirement that has to be undertaken. GreenPhylDB comprises protein sequences of 12 plant species fully sequenced that were grouped into homeomorphic families using similarity-based methods. Clusters are finally processed by phylogenetic analysis to infer orthologs and paralogs that will be particularly helpful to study genome evolution. Previously, each cluster has to be curated (i.e. properly named and classified) using different sources of information. A web interface for plant gene families’ curation was developed for that purpose. This interface, accessible on GreenPhylDB ("http://greenphyl.cirad.fr":http://greenphyl.cirad.fr), centralizes external references (e.g. InterPro, KEGG, Swiss-Prot...

Nuclear DNA and protein content evaluation in Taxus plant cell cultures using multiparameter flow cytometry

Vishal Gaurav; Amit Shavit; Susan C. Roberts
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Poster
Português
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Plant cell cultures of Taxus provide the most reliable production methods for the anti-cancer drug paclitaxel. In order to comprehend the inherent culture heterogeneity and production variability in cell cultures, it is essential that the cellular metabolism is studied at the genomic level. Genomic stability in plant cell cultures is crucial as it affects cell growth and division, metabolite accumulation and protein synthesis. A rapid and efficient method to prepare nuclei suspensions from aggregated cell cultures of Taxus was employed. Methods were subsequently developed to simultaneously stain them for DNA and protein content using Propidium Iodide and Fluorescein Isothiocyanate respectively. Flow cytometry was used to analyze and quantify the DNA content and genome size of Taxus using known reference species as standards. Furthermore, their genomic stability was evaluated by correlating DNA content and genome size with cell size and complexity, protein content, and elicitation effects using multiparameter flow cytometry. These techniques to evaluate and correlate various culture characteristics can be very useful in designing superior bio processes for enhanced production.

The power of “Green” Energy: plant trait influences on microbial competition and greenhouse gas production

Ariana Sutton-Grier; J. Patrick Megonigal
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Conferência ou Objeto de Conferência
Português
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45.91%
Background/Questions/Methods Species vary in the eco-physiological traits they possess which means species may differentially influence ecosystem functions such as microbial activity. In wetland ecosystems it is important to understand how different plant species influence microbial competition for resources because competition affects microbial respiration and one of the products of anaerobic microbial respiration is methane, a potent greenhouse gas. Plants influence the availability of substrates for microbial respiration, both available carbon and terminal electron acceptors (such as Fe(III)). Because methanogenic microbes must compete with other microbes for respiration substrates and can be out-competed if conditions are more favorable for other microbes, plants can influence the outcome of microbial competition as well as overall rates of microbial activity by changing substrate availability. In this study, we examined how plant traits related to plant productivity and carbon inputs (belowground and total biomass, and photosynthesis) and plant traits related to oxygen inputs and terminal electron acceptor availability (root porosity and Fe(III) on roots) influence microbial competition and methane production from wetland soils. Results/Conclusions Overall microbial respiration rates were positively correlated with plant productivity...