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  • Botany & Plant Biology 2007 - Abstract Search
    1 Harter Klaus 1 Dilkes Brian 2 Feldmann Ken 3 Schulz Burkhard 4 Analysis of an epigenetic suppressor of the Arabidopsis twisted dwarf1 twd1 mutation The TWISTED DWARF1 TWD1 AtFKBP42 gene of Arabidopsis encodes a immunophilin like protein which interacts with plasma membrane ABC transporters AtPGP1 and AtPGP19 This leads to regulation of polar auxin transport facilitated by ABC transporters Null mutants of AtFKBP42 are characterized by dwarfism due to impaired cell elongation and disoriented cell growth coining the name twisted dwarf1 twd1 for the gene A suppressor mutant screen resulted in twd1 sup which is a suppressor mutation of the T DNA induced twd1 2 knock out allele The phenotype of twd1 sup is intermediate between twd1 2 knock outs and wild type Ws 2 Genetic analysis showed dominance of the suppressor mutation over twd1 2 Segregation ratio of phenotypes from crosses of wild type and twd1 sup provides strong evidence for an intragenic suppressor However no sequence alterations of the TWD1 locus could be found in knock out and suppressor lines The NPTII marker of the inserted T DNA is silenced in twd1 sup plants but not in twd1 2 This reduction of NPTII expression can be overcome by treatments with the methylation inhibitor 5 azacytidine 5 azaC In addition prolonged treatments of suppressor plants with 5 azaC caused reversion of the intermediate suppressor phenotype back to the phenotype of knock out plants The same phenomenon has been observed in crosses with methylation mutants such as ddm1 met2 and hog1 Bisulfite sequencing of the TWD1 locus in twd1 sup and twd1 2 shows strong DNA methylation of the NPTII gene in twd sup but not in the null mutant line In twd sup a very low level accumulation of the full length mRNA of the TWD1 gene could

    Original URL path: http://2007.botanyconference.org/engine/search/index.php?func=detail&aid=2304 (2016-02-01)
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  • Botany & Plant Biology 2007 - Abstract Search
    of the transition from unicellularity to multicellularity with cellular differentiation primarily because of a lack of extant model organisms in lineages containing close unicellular and multicellular relatives Volvox carteri is an excellent model for studying the evolution of cellular differentiation mechanisms It is closely related to extant volvocine green algae that are unicellular or multicellular with no or incomplete division of labor between cell types It shares a common ancestor with unicellular Chlamydomonas reinhardtii that lived only 50 MYA V carteri forma nagariensis has two cell types large reproductive gonidia and small motile somatic cells The somatic regenerator gene regA encodes a product RegA that represses reproductive potential in somatic cells RegA bares no primary sequence homology to other proteins in sequence databases but is enriched in amino acids commonly found in transcription factors Analysis of the predicted secondary structure revealed that RegA contains a VARL V olvocine A lgal R egA l ike domain that resembles the poorly conserved SAND DNA binding domain Searches of the annotated C reinhardtii and the assembled V carteri genomes have revealed several genes in both genomes that potentially encode VARL domains Taken together the available evidence suggests that members of this multigene family

    Original URL path: http://2007.botanyconference.org/engine/search/index.php?func=detail&aid=1880 (2016-02-01)
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  • Botany & Plant Biology 2007 - Abstract Search
    Statement is null or not a SELECT 13 06 05 Abstract Detail Organelle Biology Kamigaki Akane 1 Hayashi Makoto 1 Mikio Nishimura 1 Analysis of Arabidopsis thaliana that was suppressed PEX10 gene expression More than 30 peroxisome biogenesis factors peroxin have been identified in several organisms It has been suggested that peroxin functions for various phases of peroxisome biogenesis including peroxisome assembly matrix protein import and peroxisome proliferation The Arabidopsis genome is predicted to encode about 20 homologous proteins to the yeast or mammal peroxins but their functions remain unclear So far we generated transgenic plants that were suppressed each peroxin gene expression using RNAi method and analyzed whether these homologues actually are responsible for peroxisome biogenesis or not Arabidopsis PEX10 is one of the peroxin that is involved in peroxisomal matrix protein import Interestingly phenotype of PEX10 suppressed plant is different from that of wild type plant whereas other peroxins suppressed plants has same phenotype of wild type plant The leaves of PEX10 suppressed plant were partially pale green after two weeks of germination The buds showed abnormal morphology and could not open in the time when a plant should bloom The pistil and stamens were bent in the

    Original URL path: http://2007.botanyconference.org/engine/search/index.php?func=detail&aid=1579 (2016-02-01)
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  • Botany & Plant Biology 2007 - Abstract Search
    Signature Sequencing Milling yield and taste are the most important aspects of rice grain quality To identify the genes involved in grain quality a deep transcriptional analysis of developing seeds was performed using Massively Parallel Signature Sequencing MPSS Five MPSS libraries were constructed from 6 day old developing seeds representing Cypress high milling LaGrue low milling Ilpumbyeo high taste YR15965 low taste and Nipponbare control cultivars Significant and reliable tags ranging between 9 721 to 13 560 were identified and matched to TIGR ESTs KOME FL cDNAs annotated genes and rice genomic sequence to identify sense antisense alternate and novel transcripts expressed in these libraries About 90 and 85 of the tags from grain quality libraries matched to the japonica and indica genomes respectively Of these nearly 78 of the tags matched to TIGR annotated genes Clustering analysis showed specific and commonly expressed tags genes among milling and taste libraries Since transcription factors TFs play a major role during seed development specific and commonly expressed transcription factors for milling and taste libraries were also identified The antisense and alternate transcripts identified in this study were further supported by public rice expression databases KOME and TIGR Numerous novel transcripts genes were also identified as expressed in these libraries A functional classification of genes using KEGG analysis showed expression and suppression of several biochemical pathways related to carbohydrate metabolism vitamins and cofactors and nucleotide metabolism Some of the genes related to starch biosynthesis a seed storage protein family and aspartate family amino acid proteins were further evaluated by RT PCR A time course study of genes involved in seed development is also being conducted Our comprehensive and deep survey of the developing seed transcriptome in five rice cultivars provide a rich genomic resource for further elucidating the molecular basis of grain quality

    Original URL path: http://2007.botanyconference.org/engine/search/index.php?func=detail&aid=224 (2016-02-01)
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  • Botany & Plant Biology 2007 - Abstract Search
    Locascio Antonella 1 Vannozzi Alessandro 1 Amasino Richard 2 Lucchin Margherita 1 Varotto Serena 1 Analysis of flowering mediated by vernalization in Cichorium intybus L Since proper timing of flowering is critical for the survival of plant species plant have evolved a complex genetic network to regulate phase transition in response to endogenous signals and environmental cues In winter annuals ecotypes of Arabidopsis a flowering repressor FLOWERING LOCUS C FLC is expressed at levels that inhibit flowering in the first growing season FLC expression is enhanced by FRIGIDA FRI then it repress the genes referred to as Floral Pathways Integrators Vernalization promotes flowering by FLC repression inducing epigenetically stable modifications Comparative genetic approaches show that flowering time genes are conserved between Arabidopsis and a large range of crop species including legumes and cereals By contrast the vernalization pathway seems to be only partially conserved since FLC and FRI were not characterized in dicots other than Brassicaceae Wild chicory Cichorium intybus L is a biennial species which requires vernalization to flower In Italy different types of chicory have been selected by farmers as leafy vegetable These types show quite different classes of precocity in relation to flowering We are investigating the molecular basis that regulate flowering in chicory by vernalization to verify whether such mechanism is the same that controls flowering in Arabidopsis and finally to address the diversity of the classes of precocity to one of the cases known for this model plant We isolated FLC homologues from chicory and characterized their expression in plant tissues We studied the pattern of cytosine methylation in chicory genomic DNA in response to vernalization In addition a vernalization mediated decrease of FLC transcript has been determinate and related with changes in SAM morphology Preliminary data indicate that arabidopsis and chicory share homologies in

    Original URL path: http://2007.botanyconference.org/engine/search/index.php?func=detail&aid=858 (2016-02-01)
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  • Botany & Plant Biology 2007 - Abstract Search
    28 Abstract Detail Plant Pathogen Interactions Tucker Mark 1 Puthoff David 2 Vinyard Bryan 3 Ehrenfried Mindy 2 Analysis of GeneChip hybridization results for RNA isolated from root pieces colonized by soybean cyst nematode Heterodera glycines Soybean cyst nematode SCN is currently the most devastating pathogen of soybean SCN penetrates the root and migrates toward the central vascular bundle where it establishes a complex multinucleated feeding structure that withdraws nutrients from the plant to support development and growth of the nematode To identify genes that may play significant roles in formation and maintenance of the feeding structure RNA from SCN inoculated and non inoculated root pieces were hybridized to the Affymetrix soybean genome GeneChips RNA was collected at 8 12 and 16 dpi from root pieces 1 to 3 mm that displayed multiple swollen female SCN and similar root pieces from non inoculated roots Branch roots and root tips were trimmed from the root pieces to minimize the amount of RNA contributed by these organs Of the 35 593 transcripts represented on the chip approximately 26 500 were expressed in the SCN colonized root pieces ANOVA followed by False Discovery Rate FDR analysis indicated that 4 616 transcripts changed significantly

    Original URL path: http://2007.botanyconference.org/engine/search/index.php?func=detail&aid=997 (2016-02-01)
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  • Botany & Plant Biology 2007 - Abstract Search
    M 2 Analysis of Green Light Effects on Arabidopsis Photomorphogenic Mutants In using custom LED light arrays it is possible to investigate the subtle effects of various quantities and qualities of light on the morphological development of Arabidopsis thaliana Previous research has shown that a unique green light sensing system contributes to subtle morphological effects in Arabidopsis The purpose of this study was to further investigate the response of Arabidopsis

    Original URL path: http://2007.botanyconference.org/engine/search/index.php?func=detail&aid=2041 (2016-02-01)
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  • Botany & Plant Biology 2007 - Abstract Search
    06 40 SQL Statement is null or not a SELECT 13 06 40 Abstract Detail Plant Pathogen Interactions Lawrence Leslie 1 Settlage Sharon 2 Hanley Bowdoin Linda 2 Analysis of host and viral DNA replication components in plants Geminiviruses are single stranded DNA viruses that infect plants Because of increasing concern regarding the susceptibility of United States crops to these viruses considerable research is being devoted to understanding and analyzing the mechanisms of geminivirus replication and infectivity Dr Hanley Bowdoin s lab is studying these processes using the geminivirus Tomato golden mosaic virus TGMV as a model My research project examined transgenic plants that express mutant versions of the geminivirus replication proteins AL1 and AL3 that have the capacity to interfere with TGMV replication and confer resistance to infection Several independent lines carrying the AL1 AL3 transgene show different resistant phenotypes To understand the basis of these phenotypes I have characterized expression of the mutant AL1 and AL3 proteins For these experiments I have used immunoblotting techniques to quantify viral protein expression in various tissues and developmental stages I used immunohistochemical techniques to visualize the fraction of cells and their types that accumulate the viral proteins Comparison of these results

    Original URL path: http://2007.botanyconference.org/engine/search/index.php?func=detail&aid=778 (2016-02-01)
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