Transcription profiling of Arabidopsis 3 day-old seedlings of acn1-2 and the parent, Col-7 in the presence/absence of sucrose
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ABSTRACT:
ORGANISM(S): Arabidopsis thaliana
SUBMITTER: unknown unknown
PROVIDER: E-NASC-29 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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Project description:The aim of this proposal is to understand the impact of the pho3 mutation on the transcriptome.The mutant pho3 was isolated on the basis of a failure to induce acid phosphatase activity in roots in response to low Pi. The pho3 mutant had a P deficient phenotype in vitro and in the leaves of soil grown pho3 plants the total P content was again reduced. pho3 exhibited a number of characteristics normally associated with low-P stress, including severely reduced growth, increased anthocyanin content and starch accumulation. pho3 was shown to have an absolute requirement for exogenous sucrose as pho3 seedlings were arrested in early seedling development on sucrose-free medium and was unaffected by Pi-availability. pho3 was found to be insensitive to high concentrations of exogenous sucrose (10%) but was sensitive to glucose. pho3 also exhibited reduced sensitivity of seed germination to exogenous ABA (abi-phenotype), a response which has been linked to sucrose insensitivity in both sugar-sensing and ABA mutants. Two developmental stages have been selected on the basis of the physiological characterisation of pho3. Seedlings (1.02; 2 rosette leaves) grown in agar and compost-grown plants (3.90; rosette growth complete). Agar will be supplemented with 1% sucrose and 1/2 strength MS; plants will be grown under a 16 h light/8 h dark cycle. Comparisons will be made between pho3 and Wassilewskija (the genetic background of the mutant) at each stage. Experimenter name: Julie Lloyd; Experimenter phone: 01206 873307; Experimenter institute: Department of Biological Sciences,; University of Essex; Experimenter address: Colchester!Series_summary = Experimenter zip/postal_code: CO4 3SQ; Experimenter country: UK Experiment Overall Design: 6 samples were used in this experiment
2008-06-11 | E-GEOD-10326 | biostudies-arrayexpress
Project description:The aim of this study is to identify genes differentially expressed during the transition between dormancy and activity in axillary shoot apical meristems. We have chosen to study this by comparing mRNA populations from the axillary buds of the auxin over-responding, apically dominant axr3-1 mutant of Arabidopsis,with those from the axillary buds of the auxin resistant axr1-12 bushy mutant. Preliminary investigation using cDNA AFLP has been successful in identifying differentially expressed transcripts in the buds of these two genotypes, thus demonstrating the importance of this study, however this is a time consuming procedure. Axillary buds from axr3-1 are seen to arrest at an early stage when the buds are approximately 2mm long and harvested at this point. Buds of a similar size were harvested from axr1-12 plants and the RNA extracted using Qiagen columns.These two mRNA samples will represent the dormant and active buds to be comparedin this experiment. The plants from which these buds were harvested were grown in adjacent p40 trays in a plant growth room. Between two and three buds were harvested from each plant. Experimenter name: Sally Ward; Experimenter phone: 01904 328683; Experimenter fax: 01904 328682; Experimenter institute: University of York; Experimenter address: Dept of Biology (Area 11),; University of York,; Heslington,; York; Experimenter zip/postal_code: YO10 5DD; Experimenter country: UK Experiment Overall Design: 2 samples were used in this experiment
2008-06-11 | E-GEOD-10324 | biostudies-arrayexpress
Project description:In recent years our group has been constructing an activation tag library based on the En-I transposon system which resulted in the identification of novel Arabidopsis mutants (Marsch Martinez et al 2002; manuscript accepted for publication in Plant Phys). Among them the bountiful (bou) mutant showed dominant alterations in leaf size and morphology, delayed flowering, vertically oriented siliques and higher yield. Sequence analysis of the genomic region flanking the transposon insertion in combination with expression analysis indicated that the mutant phenotype observed was presumably caused by over-expression of a gene encoding a yet uncharacterised DNA binding protein. In particular over-expression in the activation tagged mutant seems to cause ectopic expression of the BOU gene in all vegetative and reproductive tissues while the endogenous pattern of expression appeared to be restricted only to root tissue. Over-expression lines in which the BOU ORF was driven by the 35S promoter displayed the bountiful phenotype confirming that the activation tagged phenotype was indeed caused by activation of the BOU gene. Protein sequence analysis indicates a putative role for BOU as a chromatin remodelling factor which in association with the expression pattern suggests a possible involvement of BOU in high-hierarchy order of regulation of gene expression. Hence microarrays could be very useful for the identification of downstream interacting factors or target geneswhich will help us to gain insights towards unravelling the biological role of the BOU gene. The specific interaction to flowering time genes will be studied independently using RT-PCR to reveal the relationship to other genes in the regulatory pathway. As experimental setup we intend to compare gene expression between bountiful mutant and wild-type arabidopsis plants using rosette leaf tissue as source for RNA. Though the BOU gene is endogenously expressed in a root-specific mannerits ectopic expression in the bountiful mutant phenotipically affects the whole plant including leaves. Experimenter name: Raffaella Greco; Experimenter department: Pereira Lab; Experimenter institute: Plant Research International; Experimenter address: Business Unit Genomics; Plant Research International; Postbus 16; Wageningen; Experimenter zip/postal_code: 6700 AA; Experimenter country: The Netherlands Experiment Overall Design: 2 samples were used in this experiment
2008-06-11 | E-GEOD-10322 | biostudies-arrayexpress
Project description:Background Heterodera schachtiia is an economically important plant parasitic nematode that forms a syncytium from a cell superficial to the formed vascular bundle by progressive recruitment of other cells into the structure. The pattern of plant gene expression changes dramatically inside the syncytium. The pathogen probably plays a major role in defining the plant response by choice of initial plant cell during precise behaviour in planta and/or by the secretions it releases. The modified plant cells enable a high feeding rate by the female nematode so enhancing its rate of development and subsequent daily egg production. Arabidopsis is widely used as a model plant to characterise molecular responses to nematodes (e.g. Sijmons et al., 1991 Plant J. 1:245-254.). A complete overview of the changes in plant gene expression when sedentary nematodes establish has not yet been gained using Arabidopsis or any other host plant. Experimental Approaches Our initial studies will focus on the H. schachtii/Arabidopsis interaction. To assure reliable microarray screening care has been taken to minimise extraneous differences between samples (see "Growth conditions" section). At 21 days (Growth stage 3.2-3.5 Boyes et al., 2001 Plant Cell 13:1499-1510) Arabidopsis plants were challenged with rigorously sterilised, infective nematodes of H. schachtii as before (Urwin et al., (1997) Plant Journal 12: 455-461.). 35 sterile J2s were pipetted onto small ~0.5mm2 squares of sterile GF/A filter paper. The GF/A paper was left in direct contact with the zone of elongation on 3 lateral roots per plant for 48 hours. Control plants were mock inoculated with sterile water. Sections of root containing syncytia have been excised from the thin and transparent roots of Arabidopsis and collected into RNAlater solution (Ambion) at 21 days post infection (Growth Stage 6.1 Boyes et al. 2001). The female nematode has been removed with watch-maker's forceps. Equivalent sections of root have been harvested from non-infected plants. Material has been collected from c. 1000 plants for each of the two samples and the uninfected material serves as an internal control. Total RNA has been prepared from the reference and test root material using an RNeasy plant RNA preparation kit (Qiagen) according to methods required by GARNET.
2022-11-21 | E-NASC-3 | biostudies-arrayexpress
Project description:Agrobacterium tumefaciens, a bacterial species found in temperate soils world wide, is the causative agent of crown gall disease on many plants. A. tumefaciens-induced tumours are feared in orchards and vineyards because of their pathological interference with nutrient and water supply which results in crop decline. Small wounds at the crown of the plant, usually induced by wind-bending, are potential entry sites for the bacterium. The tumorous growth is initiated by the integration and expression of the T-DNA of the bacterial Ti plasmid within the plant nuclear DNA. The T-DNA encodes enzymes catalysing the synthesis of increased concentrations of auxin and cytokinin, and of opines which stimulate cell division and enlargement. The fast growing tumours have been shown to be a strong nutrient sink on their host plants. As a matter of fact, sugar and K+ content were found to be up to 10- and 5-fold, respectively, higher in this tissue and transpiration was about 15 times increased compared to normal tissue. Whereas the morphological structure as well as some physiological and biochemical parameters of the tumour have been analysed in detail, little is known about the underlying gene expression pattern. Proliferation and growth of the tumour induced by Agrobacterium tumefaciens is obviously due to the extraordinary high concentration of phytohormons, minerals and metabolites. Their influence on regulation of gene transcription will provide information on the mechanisms underlying fast tumour growth. In a project funded by the DFG we recently started to investigate the role of solute transporter for tumour development on the model plant Arabidopsis thaliana. By comparing the expression pattern of RNA preparations from Arabidopsis tumour and non-tumour tissue, we will be able to identify genes which facilitate crown gall development. For the expression analysis with an Affymetrix full genome chip we will induce tumours at the base of an injured Arabidopsis inflorescence stalk (var. Wassilewskija, WS-2). RNA will be extraxted from tumour and injured non-tumor inflorescence stalk tissue using the RNeasy Plant Mini Kit (Qiagen), followed by a DNase treatment to eliminate DNA contamination.
2022-11-21 | E-NASC-21 | biostudies-arrayexpress
Project description:Transcript profiling is crucial to study biological systems and various platforms have been implemented to survey mRNAs at the genome scale. We have assessed the characteristics of the CATMA microarray designed for Arabidopsis thaliana transcriptome analysis, and compared it with two commercial platforms from Agilent and Affymetrix. The CATMA array consists of gene-specific sequence tags of 150 to 500 base pairs, the Agilent (Arabidopsis 2) array of 60mer oligonucleotides, and the Affymetrix gene chip (ATH1) of 25mer oligonucleotide sets. We have matched each probe repertoire with the Arabidopsis genome annotation (TIGR release 5.0) and determined the correspondence between them. Array performance was analyzed by hybridization with labeled target derived from eight RNA samples made of shoot total RNA spiked with a calibrated series of 14 control transcripts. A total of fourteen cDNA clones were thus selected and used as templates to synthesize bona fide polyadenylated spike RNAs. Each spike RNA was calibrated then mixed in equal amount with one of the other spike RNAs to obtain seven pairs at equal concentration. These seven spike RNA pairs were then combined systematically to construct seven complex spike mixes in a design similar to an ordered Latin square, each mix containing six of the seven spike pairs in staggered concentrations covering five logs. To prevent loss of spike RNA through adsorption to the plastic ware, the spike mixes were prepared in 0.5 µg/µl Col RNA, resulting in a range of concentration from 0.1 to 10,000 copies per cellular equivalent (cpc), assuming that the total RNA contained 1% polyadenalated mRNA and that a cell contained on average 300,000 transcripts. These seven RNA samples included equal amounts of combined spike RNA . To convert the spike hybridization signals to ratios, an eighth sample was prepared, called the reference sample, consisting of the base Col RNA completed with all spike RNAs at a concentration of 100 cpc. The results from the eight experiments using the Affymetrix gene chips (ATH1) are available for analysis or download from this site.
2022-11-21 | E-NASC-43 | biostudies-arrayexpress
Project description:The acclimation of plants to environmental factors (light/temperature/nutrient availability) plays a crucial role in determining their tolerance to stress their ability to compete with other plants and the efficiency with which external inputs are used for growth and productivity. Some of the clearest responses involve the major modifications in the composition of the photosynthetic apparatus in response to light intensity. Photosynthetic acclimation. The acclimation response involves changes in the abundance of a large number of proteins in different cell compartments occurring at different intensity thresholds. The signal transduction chain is complex and involves crosstalk between redox control and other pathways that control photosynthetic gene expression but is poorly understood. Over the past 7 years we have laid the foundations for a molecular genetic approach by characterising the responses of Arabidopsis thaliana to growth in and transfer between high and low light conditions(1-6). Arabidopsis exhibits all the key features of photosynthetic acclimation: changes in maximum photosynthetic rate in leaf structure and in the levels of light-harvesting complexes photosystems and enzymes of carbon metabolism. Method: Samples A-1, A-2 and A-3 were grown at a light intensity of 400 umol.m-2.s-1 until rosette growth was complete. Plants for samples A-2 and A-3 were then transferred to 100 umol.m-2.s-1. Samples A-4, A-5 and A-6 were grown at 100umol.m-2.s-1 until rosette growth was complete, when plants for samples A-5 and A-6 were transferred to 400 umol.m-2.s-1. Samples were taken 24 hours after transfer to the different light intensity and samples A-3 and A-6 were taken 72 hours after transfer.
2022-11-21 | E-NASC-34 | biostudies-arrayexpress
Project description:We have been determining signalling components essential for heat tolerance in Arabidopsis thaliana (Larkindale, J., and Knight, M.R. (2002). Protection against heat stress-induced oxidative damage in Arabidopsis involves calcium, abscisic acid, ethylene, and salicylic acid. Plant Physiol 128, 682-695). We have most recently found that a heat-induced respiratory burst is necessary for tolerance to high temperatures in Arabidopsis (Larkindale, Torres, Jones and Knight, unpublished). We have observed that one of the Arabidopsis respiratory burst homologues, AtrbohB, is necessary for the generation of this AOS burst in response to heat, and consequently we have also found that an AtrbohB null mutant shows reduced tolerance to heating (Larkindale, Torres, Jones and Knight, unpublished). This mutant also shows reduced expression of genes from the HSP90 family (Evans, Larkindale and Knight, unpublished).This application is for transcriptomic analysis of the AtrbohB null mutant in response to heat, in order to understand which genes are activated as a result of heat-induced respiratory bursts in Arabidopsis and also which genes are necessary for physiological thermotolerance in Arabidopsis. The experiment will involve 6 samples (chips), 3 from wild type Columbia and 3 from the AtrbohB null mutant. Seedlings will be treated at 20, 30 and 40 degrees centigrade for 1 hour, RNA extracted and submitted to microarray analysis. One hour treatment has been shown to display clear differences in HSP90 expression and physiological damage, and the temperatures chosen because 30 degrees is a temperature at which acquired thermotolerance can be initiated (thus genes involved in this process can be monitored) and 40 degrees is a temperature at which we observe physiological damage, and gives good discrimination between mutant and wild type.
2022-11-21 | E-NASC-24 | biostudies-arrayexpress
Project description:Background: Since chemical assays of soil nutrients are unreliable the UK horticultural and agricultural industries routinely apply large amounts of inorganic fertiliser to maintain crop yields and quality. Excessive fertiliser applications are both costly and can lead to unnecessary pollution. A possible solution to this problem is to use sensor (GM or non-GM) technologies that exploit the changes in plant gene expression profiles under incipient nutrient deficiency. The aim of this project is to identify genes upregulated in the early stages of nutrient depletion. Methods: Arabidopsis ecotype Col-5 (N1644) will be grown hydroponically using established techniques. In parallel experiments NP and K will be withdrawn individually after 21 d growth. RNA will be extracted from shoots of nutrient replete (control) and nutrient depleted plants 24 h after the removal of nutrients. Shoot nutrient content will be assayed by ICP-EMS as a reference. By comparing expression profiles we will be able to differentiate between genes that are upregulated by lack of specific nutrients and those upregulated by a universal stress-response system. Promoters and transcripts of these genes will underpin the development of novel sensor technologies and knowledge of the gene expression profiles will improve our understanding of the physiology of plant mineral nutrition.
2022-11-21 | E-NASC-59 | biostudies-arrayexpress
Project description:Mutations in the heterotrimeric G-protein a-subunit of Arabidopsis, GPA1, leads to deficiency in ABA-induced stomatal closure (Wang et al., 2001). To further investigate whether GPA1 is involved in the regulation of gene expression in response to ABA, we examined the induction of known ABA-inducible genes in the gpa1 mutant and compared it to wild-type. We found significant differences in levels of ABA-induced expression between wild-type and gpa1 mutant. In order to systematically investigate GPA1 involvement in ABA signalling leading to gene expression, we are requesting the transcriptome analysis of the gpa1 mutant in response to ABA.In detail, 2 week old wild-type and gpa1 plants grown in the 16/8 hrs light and dark cycle will be treated with either ABA or with a control solution for 3 hours. 10 plants will be used per sample to produce RNA, to give 4 samples, one for each chip: gpa1-1 mutant in the presence (chip1) or absence of ABA (chip2) and wild-type (WS2) in the presence (chip3) or absence of ABA (chip4).
2022-11-21 | E-NASC-45 | biostudies-arrayexpress