Transcription profiling of Arabidopsis short day grown hypocotyls to identify genes involved in secondary cell wall development
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ABSTRACT:
ORGANISM(S): Arabidopsis thaliana
SUBMITTER: Nottingham Arabidopsis Stock Centre (NASC)
PROVIDER: E-GEOD-6153 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:Arabidopsis, when grown under short day conditions (16 hours dark, 8 hours light, 22oC) develop extensive secondary thickened hypocotyls with both a vascular and cork cambium (Chaffey et al, 2002, Phys. Plant., 114:594-600). It has been found that once secondary xylem development is completed within the Arabidopsis hypocotyls, it closely resembles the structure of the wood of angiosperm trees (Chaffey et al, 2002, Phys. Plant., 114:594-600). We can utilise this model Arabidopsis tree to identify genes that are important for secondary cell wall formation in xylem cells and therefore important for wood development. Columbia plants were grown for 3 months under short day conditions and secondary thickened hypocotyls were snap-frozen in liquid nitrogen. RNA was isolated from these hypocotyls and submitted to NASC for probing against the ATH1-121501 full GeneChip.
2022-11-21 | E-NASC-58 | biostudies-arrayexpress
Project description:Arabidopsis, when grown under short day conditions (16 hours dark, 8 hours light, 22oC) develop extensive secondary thickened hypocotyls with both a vascular and cork cambium (Chaffey et al, 2002, Phys. Plant., 114:594-600). It has been found that once secondary xylem development is completed within the Arabidopsis hypocotyls, it closely resembles the structure of the wood of angiosperm trees (Chaffey et al, 2002, Phys. Plant., 114:594-600). We can utilise this model Arabidopsis tree to identify genes that are important for secondary cell wall formation in xylem cells and therefore important for wood development. Columbia plants were grown for 3 months under short day conditions and secondary thickened hypocotyls were snap-frozen in liquid nitrogen. RNA was isolated from these hypocotyls and submitted to NASC for probing against the ATH1-121501 full GeneChip. Keywords: growth_condition_design
2007-01-22 | GSE6153 | GEO
Project description:Plants that exhibit secondary growth, such as trees, are a prominent feature of terrestrial ecosystems. Furthermore, secondary growth itself, particularly wood, has huge economic value. Despite the importance of secondary growth from both basic and applied science perspectives, little is known about the molecular mechanisms that underpin this facet of plant development. The proposed microarray experiments are designed to expand our knowledge of the regulation of secondary growth by combining the power of Arabidopsis genetics with complete transcriptome analysis. It is now well established that Arabidopsis can be grown under conditions that induce secondary growth in the hypocotyl, albeit small, wood. We have grown 8500 Arabidopsis plants of different genotypes under these conditions and will extract RNA from the developing vascular cambia of these plants to subject them to complete transcriptome analysis.The mutants that we have chosen for these analyses are all related to each other on the basis of the fact that they impact dormancy in either seeds or shoots (abi1, aba1, max4, axr1, AtMYB61 knockout, AtMYB50 knockout). The mutants themselves are the core group of mutants that are the focus of a three laboratory consortium, funded under the BBSRC Exploiting Genomics Initiative, to investigate the molecular basis of meristem dormancy in Arabidopsis. The other partners in the consortium are Dr. Ottoline Leyser (York) and Dr. Michael Holdsworth (IACR). While the Leyser and Holdsworth groups have investigated the impact of these mutations on transcriptome activity in shoot meristems and seeds respectively, our work focuses on the vascular cambium. Thus, this work will not only provide insights into the regulation of cambial function, but, when compared with the existing datasets from the Leyser and Holdworth labs, the work should also provide insights into the relationship between dormancy-impacted phenomena in different meristematic regions. Beyond this, the specific work on the cambium-specific regulation of genes in the MYB61KO will provide even greater insights into the functioning of this important resource allocation regulator, as it will build on a significant complete transcriptome dataset that is already available through GARNet. In total, the proposed analyses will generate important new data that builds on existing datasets, to provide an even more comprehensive understanding of gene function, and genetic networks, in an important biological and applied context. Please note that the sample numbers that we have provided below are meant to be the 'base' number for each biological condition (mutant, etc.), and that there will be independent TRIPLICATE biological replicates produced for each condition. (ie. A-1 to A-12). Experiment Overall Design: Number of plants pooled:200-400 per RNA sample
2008-06-14 | E-GEOD-6151 | biostudies-arrayexpress
Project description:Arabidopsis acetate non-utilizing mutants were isolated based on fluoroacetate resistant germination. Interestingly, a number of these mutants exhibited altered developmental characteristics in response to exogenous sucrose supply, such as bleaching of the cotyledons. A preliminary microarray experiment has already been conducted on one of the mutants, acn1-2. The gene expression analysis was done using 3 day-old seedlings of acn1-2 and the parent, Col-7, which were germinated on agar plates with and without exogenous sucrose. A cross-comparison of acn1-2 and Col-7 revealed that the expression of a number of carbohydrate responsive genes was altered in the mutant. The request for further microarray analysis is to confirm this result. Experiment Overall Design: Number of plants pooled:3 x 1000 seedlings
2008-06-14 | E-GEOD-6158 | biostudies-arrayexpress
Project description:This proposal is aimed at providing transcriptome data to underpin a long-term joint research programme of Steve Smith and Alison Smith. We are jointly studying starch synthesis and breakdown in Arabidopsis leaves, and individually studying other enzymes of carbohydrate metabolism (eg. sucrose synthases, invertases, sugar transporters). Collectively these enzymes are encoded by up to 100 known genes, but there are many others of relevance to our studies. For several years we have employed a defined set of growth conditions for this work (resulting in numerous publications). We have extensive data for changes in the amounts of starch, malto-oligosaccharides and sugars throughout the diurnal cycle in these plants, and we intend to quantitate numerous key enzymes. We now wish to profile changes in transcripts in these plants, so that this information can be correlated with changes in the amounts of key enzymes and metabolites. Analysis of the data sets will help us to relate the synthesis of certain enzymes to particular metabolic functions, and also to help identify genes encoding novel proteins involved in carbohydrate metabolism. Current research is aimed at discovering such novel proteins using proteomics approaches (BBSRC Grant: _Discovery and Functional Analysis of the Starch Proteome_). While the growth conditions (12h photoperiod, 150 umol/m2/s, 20C) and ecotype (Col-0) are specifically tailored to our experiments, they will be of value to the wider community, and could form the basis for collaborative studies with other groups. The experiment has involved sampling leaves at eleven different time points as follows: 0, 1, 2, 4, 8, 12, 13, 14, 16, 20, and 24 h (where time 0 is the onset of dark and 12 h is the onset of light). The 24 h time point is a repeat of 0 h. This sequence provides relatively more samples immediately after the light-dark transitions, when changes in metabolism are most pronounced. Plants were grown in a controlled environment chamber under defined conditions, and selected for harvest according to a random number generator. Three fully expanded leaves were harvested from each of 20 plants for each sample. Leaves were frozen at -80 C and a portion saved for metabolite and enzyme assays while RNA was isolated from the remainder. The RNA has been purified and is ready to send to Nottingham. Experiment Overall Design: Number of plants pooled:20 Experiment Overall Design: Biological replicates: 2
2008-06-14 | E-GEOD-6174 | biostudies-arrayexpress
Project description:The mutants iae1 and iae2 have been mapped to two distinct loci on chromosome 2. With the aid of the GetCID service, we believe iae1 has been localised to a relatively small region (~100kb); while mapping has restricted iae2 to a small interval (~50kb) with a very limited number of candidate genes. Although it has proved difficult to determine which gene is mutated in iae1, we belive that use of the transcriptomics service will help identify which genes are affected (directly and indirectly) in this background. The iae2 locus is sufficiently restricted by genetics and by molecular data that identifying a candidate (and any downstream loci affected) should be straightforward. We require the use of the full genome chips. The data from this experiment should help tie together the data we have for a paper that is currently in preparation. Experiment Overall Design: Number of plants pooled:30 (done)
2008-06-14 | E-GEOD-6175 | biostudies-arrayexpress
Project description:Our goals are to discover the basis of the stress-sensitive phenotypes of the sfr2, sfr3 and sfr6 mutants, and to distinguish damage-repair from damage-prevention-related transcription in the wild type. The effects of sfr2 and sfr3 on cold-induced gene expression will be observed. Since sfr6 causes sensitivity to drought as well as freezing, the effects of sfr6 on the transcriptional response to drought is studied; an observation of cold-induced sfr6 expression is needed for direct comparison to the effect of drought. Unstressed mutants, and equivalently-stressed wild types, are necessary controls. The above experiments are conducted on tissue-culture-grown plants grown under 24 hr illumination for maximum reproducibility and comparability to other transcriptomic experiments.Freezing causes physiological changes even in a hardy, cold-acclimated wild type. During the recovery period, gene expression will reflect the induction of damage-repair processes distinct from the damage-prevention associated with cold acclimation. This will be detected by observing the wild-type transcriptome at two time points during recovery from a freezing episode. The appropriate controls is the unfrozen, cold-acclimated wild type. Plants for this experiment will be soil-grown in an 9/15 day/night cycle to the rosette stage, and this regime will be maintained during acclimation and freezing treatments.Cold-induction will be 10 days at 4°C; drought will be imposed by placing excised leaves in a desiccator for 6 h. The youngest fully-expanded rosette leaves will be harvested for RNA extraction. Experiment Overall Design: Number of plants pooled:18
2008-06-14 | E-GEOD-6177 | biostudies-arrayexpress
Project description:Nitric oxide (NO.) is a well-established signal in mammalian cells regulating e.g. smooth muscle tone, neurotransmission and apoptosis. NO interacts with superoxide (O2-) to derive the highly reactive peroxynitrite (ONOO-) radical leading to the generation of lipid hydroxy-peroxides (ROO.) and cell death. Thus the recent reports implicating of .NO in the Hypersensitive Response (HR) a form of programmed cell death elicited by pathogens in plantsis suggestive of parallel roles in animals and plants. As part of BBSRC funded programmes which are investigating oxidative signaling and cell death in Arabidopsis we have collaborated with the Trace Gas Detection facility at the University of Nijmegen to be the first to measure NO in planta from a developing HR (Mur et al.paper in prep). The challenge remains to understand the spatio-temporal role(s) of .NO during the HR and disease development. In line with other groups e.g. Klessig et al.(2000) PNAS 978849-55 we have observed that .NO mediated event are both SA- dependent and independent. We propose a two-stage programme to investigate NO events which will lead to subsequent BBSRC grant bids. Firstly to exploit the GARNET Affymetrix transcriptomic service to identify genes which are upregulated by .NO (see programme below). These will be compared with similar data generated by other members of the consortium; Dr. Steve Neill for oxidative stress (Desikan et al. (2001). Plant Physiol 127(1): 159-72; Clarke et al.2000 Plant J.; 24:667-77); Dr. Paul Kenton who is mainly interested in signaling by the oxylipid Jasmonic acid (Kentonet al. (1999). MPMI 12(1): 74-78) as well as from other sources. Though these data in themselves will suggest modes of NO action. However as a second approach we will clone the promoter of a strongly NO-responsive gene which will be fused to positive and negative selectable markers as well as reporter genes e.g. LUC. to identify Arabidopsis EMS mutants which are perturbed in NO-mediated events. Programme. Our in planta measurement show that from a baseline production of 1nl.g fwt-1h-1 NO levels rise to 6nl. g fwt-h-1 (_plus/- 1.1 SE) prior to cell death and to 25nl g fwt-h-1 (_plus/- 4.2 SE) at cell death following which the concentration falls. At this juncture we will intend to gas Arabidopsis to ~75ppb (the head-space concentration when NO production was at 6nl. g fwt-h-1). Prior to using the DNA RNA will establish that this does not elicit cell death over the proposed treatment period and that both PR1 (SA-dependent) and PAL1 (SA-independent) genes are induced. We will compare this plant with sealed but non-treated Arabidopsis. Future targets for DNA RNAs analysis induce plant treated with both NO (Sodium Nitro Prusside) and O2- (Xanthine oxidase) generators and depending on their effectiveness (to be assessed by NO measurement) HR lesions treated with Nitric Oxide Synthase inhibitors. Experiment Overall Design: Number of plants pooled:8
2008-06-14 | E-GEOD-6170 | biostudies-arrayexpress
Project description:As part of an investigation into mechanisms of HDG silencing in Arabidopsis, we have produced transgenic plants containing extra copies of the chalcone synthase (CHS) gene. The CHS gene mediates an early step in the biosynthesis of the purple pigment anthocyanin. The insertion of extra copies of CHS in Arabidopsis caused the gene to be silenced in some plants. Seeds harvested from these CHS-silenced plants were mutated by treatment with ems. The progeny of these seeds were screened for "revertants" in which the effects of CHS silencing was alleviated and plants were able to produce anthocyanin. These revertants were found to contain a single recessive mutation; the trait has been termed hog1 (for homology dependant gene silencing 1). Our previous experiment used the Affymetrix 8200 chip to make comparisons between gene expression in the two genetic variants: the CHS-silenced type (ECG) and the anthocyanin-producing revertants (15B). Results showed that there were over 100 genes with at least a 10-fold increase or decrease in expression. However, the variation between 2 reps of each genetic variant was high. We would now like to carry out a modified version of this experiment using the 25K Affymetrix chip. It is intended to increase the number of reps to 4, and take samples at an earlier stage than previously in order to decrease the effect of developmental spread. To reduce the effects of interplant variability, samples will be generated from total plant tissue from a pool of 10 plants at GS 1.04. RNA will be purified using RNeasy kits from Qiagen. Experiment Overall Design: Number of plants pooled:10 Experiment Overall Design: Biological replicates: 4
2008-06-14 | E-GEOD-6166 | biostudies-arrayexpress
Project description:This application is the second part of a BBSRC-funded grant to compare and contrast the plastid-signalling pathways disrupted by Norflurazon and far-red light treatment of Arabidopsis seedlings. The first application of this laboratory to GARNet's Affymetrix service (2002-08-25-17.41.49_McCormac) addressed the Norflurazon pathway; this application addresses the far-red pathway. The assembly of photosynthetic complexes in developing chloroplasts is critical to the establishment of the autotrophic plant. This requires light-mediated upregulation of both nuclear- and chloroplast-encoded genes. The expression of such photosynthetically-associated nuclear genes is also often dependant on a retrograde plastid signal which emanates from chloroplasts to modulate nuclear transcription. Extensive studies using the herbicide Norflurazon to knock-out the plastid signal (including this lab's previous Affymetrix application to GARNet) are identifying the affected gene sets. However, genetic studies have indicated the existence of more than one plastid signalling pathway. We have recently investigated a phytochrome A-mediated, far-red (FR) input pathway which blocks subsequent chloroplast development under white light (WL). This has also been found to inhibit the transcription of a small group of known nuclear-encoded plastidic proteins. Here we wish to establish how wide-reaching this FR-effect is on nuclear transcription, and will directly compare the affected gene groups with those identified from our earlier (and other's) studies with a Norflurazon treatment. In this array experiment we will compare RNA from seedlings grown in complete darkness (D) before transfer to WL, with that of seedlings preconditioned under a restricted wavelength FR source before exposure to WL. This comparison of FR- and Norflurazon-affected gene groupings will indicate whether the plastid signalling pathways are likely to be the same, overlapping or highly divergent. As well as wild-type seedlings, the gun1,gun5 mutant line is to be used as both these alleles are well established as alleviating the Norflurazon-inhibited pathway, but their affect on the FR-pathway is less clear. A single replicate of a phyA-null mutant line will also be included in order to differentiate between specific phytochromeA-mediated responses and other FR effects. It is envisaged that, in general, D- and FR-treated samples of the phyA mutant line will respond in the same way as each other and as the wild-type D-treated samples and, thus, the lack of a biological repeat in this case is not a major short-fall. The proposed experiment will consist of: wild-type: D-pretreated (x2 biological replicates) wild-type: FR-preconditioned (x2) gun1,gun5: D-pretreated (x2) gun1,gun5: FR-preconditioned (x2) phyA: D-pretreated (x1) phyA: FR-preconditioned (x1) Experiment Overall Design: Number of plants pooled:300 seedlings
2008-06-14 | E-GEOD-6169 | biostudies-arrayexpress