Project description:Large-scale identification of transcripts with large cross-genotype differences in abundance provides a genome-wide approach to identify natural variation in gene function. Transcript profiling was performed in 20 Arabidopsis accessions at dusk, dawn and after a 6h extension of the night. Individual genes with a high variance in transcript abundances across accessions were identified by inspection at each individual time point and by ANOVA across all three time points. Up to 40% of genes show significant changes in transcript abundance between accessions, with over-enrichment for biotic resistance, including pathogenesis resistance proteins and glucosinolate metabolism, cell wall modification, minor carbohydrate metabolism, amino acid degradation, brassinosteroid metabolism, redox and abiotic stress and underrepresentation of photosynthesis, DNA synthesis, RNA processing, regulation of transcription, protein synthesis and protein targeting. Some functional classes were enriched at all three time points. Genes related to carbon starvation-responses were enriched specifically at dawn, when their transcript abundance varied independently of carbohydrate levels, pointing to genetic variation in the sensitivity with which low carbon is sensed. Cross-accession correlation networks were generated at each time point to identify sets of genes whose transcripts show coordinated change in abundance between accessions. A cluster that was highly enriched for cold-response genes was found at dusk and after an extension of the night. Another cluster found at all three time points was highly enriched for glucosinolate biosynthesis, and correlated with glucosinolate content. We conclude that genes involved in stress and defense related processes show especially large and coordinated natural variation in transcript abundance.
Project description:Arabidopsis thaliana and Eutrema salsugineum show the ability to cold acclimate. However, the degree of freezing tolerance depends in both cases on the accession. To elucidate the transcriptional basis of this differencial freezing tolerance, we performed where we grew plants under control conditions (20°C/18°C day/night) or under cold conditions (additional 4°C for 2 weeks). Rosettes were harvested from non-acclimated and cold acclimated plants for RNA isolation. Expression patterns were compared between treatments, accessions and species.
Project description:We report the results of a genome-wide analysis of AS in Arabidopsis thaliana plants exposed to a 2h light pulse given in the middle of the night, a treatment that simulates the effects of early dawn or late dusk signals. This light affects the plant transcriptome at multiple regulatory layers, and that light regulation of mRNA levels of splicing regulatory factors is likely to mediate light effects on AS contributing to adjust plant physiological processes to the prevailing light environment.
Project description:Usually starch is nearly depleted at the end of the night. To induce a gradual depletion of carbon, we have analysed the global response of transcripts during an extension of the night, where carbon becomes severely limiting from about four hours onwards. Experiment Overall Design: Arabidopsis thaliana rosettes were harvested in successive timpoints in an extended night situation.
Project description:gene expression profiling in different zones along the gradient of the growing maize leaf balde aover a time course of dirunal cycle and carbon starvation by extension of the night Plants assimilate carbon in their photosynthetic tissues in the light. However, carbon is required during the night, and in non-photosynthetic organs. It is therefore essential that plants manage their carbon resources spatially and temporally and coordinate growth with carbon availability. In growing maize (Zea mays) leaf blades a defined developmental gradient facilitates analyses in the cell division, elongation and mature zones. We investigated the responses of the metabolome and transcriptome and polysome loading, as a qualitative proxy for protein synthesis, at dusk, dawn and 6, 14 and 24 hours into an extended night, and tracked whole leaf elongation over this time course. Starch and sugars are depleted by dawn in the mature zone, but only after an extension of the night in the elongation and division zones. Sucrose recovers partially between 14 and 24 h into the extended night in the growth zones but not the mature zone. The global metabolome and transcriptome track these zone-specific changes in sucrose. Leaf elongation and polysome loading in the growth zones also remain high at dawn, decrease between 6 and 14 h into the extended night and then partially recover indicating that growth processes are determined by local carbon status. The level of sucrose-signaling metabolite trehalose-6-phosphate, and the trehalose-6-phosphate:sucrose ratio are much higher in growth than mature zones at dusk and dawn but fall in the extended night. Candidate genes were identified by searching for transcripts that show characteristic temporal response patterns or contrasting responses to carbon starvation in growth and mature zones.
Project description:a2e_heterosis - cgh_colvsc24_wg - Arabidopsis thaliana accessions (Col-0, C24 and Cvi) and their hybrid were used to investigate the dynamics of the epigenome after intraspecific hybridization between - Comparative genome hybridization between Arabidopsis thaliana accessions Col-0 and C24.
Project description:a2e_heterosis - cgh_colvscvi_wg - Arabidopsis thaliana accessions (Col-0, C24 and Cvi) and their hybrid were used to investigate the dynamics of the epigenome after intraspecific hybridization between - Comparative genome hybridization between Arabidopsis thaliana accessions Col-0 and CVi.
Project description:a2e_heterosis - cgh_colvsc24_chr4 - Arabidopsis thaliana accessions (Col-0, C24 and Cvi) and their hybrid were used to investigate the dynamics of the epigenome after intraspecific hybridization between - Comparative genome hybridization between Arabidopsis thaliana accessions Col-0 and C24 Keywords: cgh,chip-chip
Project description:gene expression profiling in different zones along the gradient of the growing maize leaf balde aover a time course of dirunal cycle and carbon starvation by extension of the night Plants assimilate carbon in their photosynthetic tissues in the light. However, carbon is required during the night, and in non-photosynthetic organs. It is therefore essential that plants manage their carbon resources spatially and temporally and coordinate growth with carbon availability. In growing maize (Zea mays) leaf blades a defined developmental gradient facilitates analyses in the cell division, elongation and mature zones. We investigated the responses of the metabolome and transcriptome and polysome loading, as a qualitative proxy for protein synthesis, at dusk, dawn and 6, 14 and 24 hours into an extended night, and tracked whole leaf elongation over this time course. Starch and sugars are depleted by dawn in the mature zone, but only after an extension of the night in the elongation and division zones. Sucrose recovers partially between 14 and 24 h into the extended night in the growth zones but not the mature zone. The global metabolome and transcriptome track these zone-specific changes in sucrose. Leaf elongation and polysome loading in the growth zones also remain high at dawn, decrease between 6 and 14 h into the extended night and then partially recover indicating that growth processes are determined by local carbon status. The level of sucrose-signaling metabolite trehalose-6-phosphate, and the trehalose-6-phosphate:sucrose ratio are much higher in growth than mature zones at dusk and dawn but fall in the extended night. Candidate genes were identified by searching for transcripts that show characteristic temporal response patterns or contrasting responses to carbon starvation in growth and mature zones. 3 repliucates per time point and leaf region, each pooled form 5 indiviual plants
Project description:Arabidopsis thaliana exhibits differential susceptibility to the fungal pathogen Botrytis cinerea depending on the time of day that infection occurs. We hypothesised that this is driven by teh circadian clock and that differences in the amplitude or speed of the plant defence response will underlie the difference in susceptiblity. A major component of the defence response is transcriptional reprogramming, hence we investigated whether the transcriptional response to B. cinerea infection differs following inoculation at subjective dawn or night (the points of greatest difference in susceptiblity) under constant light conditions.