Project description:Polyethilenimine (PEI) functionalized single walled carbon nanotubes (SWNTs) and carbon-based nanomaterials enable delivery of DNA and RNA in plants. Given the broad-scale use of PEI-functionalized nanomaterials in plants, we sought to investigate the reaction of plant tissues to treatment with PEI-SWNTs and pristine SWNTs. To this end, we infiltrated Arabidopsis thaliana leaves with pristine single walled carbon nanotubes used in RNA silencing applications (SWNTs) and polyethyleneimine-functionalized SWNTs used for plasmid DNA delivery (PEI-SWNTs). We used Arabidopsis as it is a well characterized model plant, for which genomic and detailed gene function information is readily available. To minimize the effects caused by the introduction of exogenous nucleic acids, in SWNT preparations we used single stranded RNA targeting Green Fluorescent Protein (GFP) with no target sequence in the Arabidopsis genome, and a plasmid that expresses GFP in PEI-SWNT preparations. For our experiments herein, we used ~25-50 fold higher concentrations of SWNTs and PEI-SWNTs compared to standard concentrations used in biomolecule delivery assays. Water-infiltrated plant leaves served as a negative control to distinguish between the SWNT-specific response and the response to the infiltration process itself. We performed RNA sequencing (RNA-seq) with RNA extracted from leaves two days after infiltration to identify changes in the leaf transcriptomic profile in response to the three treatments, compared to non-infiltrated leaves.
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: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:The aim of our study is to investigate the effects of carbon ion and photon irradiation on A549 tumor cells and analyse how these effects are altered by PML knockdown. Therefore we created PML knockdown A549 cells (shPML) and irradiated them with either 2Gy carbon ion or 6Gy Photon (bioequivalent doses). 4 days after irradiation microarray analysis was performed. All experiments were performed in 3 biological replicates and control groups were transduced with an empty vector.
Project description:In order to screen for molecules contributing to the effects of FGF1/CPP-C on radiation-induced intestinal damage, the total RNA expression profile of the irradiated jejunum was obtained using a DNA microarray analysis after Carbon-ion irradiation with the FGF1/CPP-C pretreatment.
Project description:One-carbon metabolism is an essential branch of cellular metabolism that intersects with epigenetic regulation. Here, we show formaldehyde, a one-carbon unit derived from both endogenous sources and environmental exposure, regulates one-carbon metabolism by inhibiting the biosynthesis of S-adenosylmethionine (SAM), the major methyl donor in cells. Formaldehyde reacts with privileged, hyperreactive cysteine sites in the proteome, including Cys120 in S-adenosylmethionine synthase isoform type-1 (MAT1A). Formaldehyde exposure inhibited MAT1A activity and decreased SAM production with MAT-isoform specificity. A genetic mouse model of chronic formaldehyde overload showed a decrease in SAM and in methylation on selected histones and genes. Epigenetic and transcriptional regulation of Mat1a and related genes function as compensatory mechanisms for formaldehyde-dependent SAM depletion, revealing a biochemical feedback cycle between formaldehyde and SAM one-carbon units.
Project description:The aim of our study is to investigate and compare the effects of carbon and photon irradiation on microvascular endothelial cells. Therefore we irradiated human pulmonary microvascular endothelial cells (HPMEC) with either 2Gy Carbon or 6Gy Photon (bioequivalent doses) and performed microarray analysis both 2 hours (short-term effect) and 6 days (long-term effects) after irradiation. All experiments were performed in 3 biological replicates.