Project description:Although processed potato tuber texture is an important trait that influences consumer preference, a detailed understanding of tuber textural properties at the molecular level is lacking. Previous work has identified tuber pectin methyl esterase activity (PME) as a potential factor impacting on textural properties and the expression of a gene encoding an isoform of PME (PEST1) was associated with cooked tuber textural properties. In this study a transgenic approach was undertaken to investigate further the impact of the PEST1 gene. Antisense and over-expressing potato lines were generated. In over-expressing lines tuber PME activity was enhanced by up to 2.3 fold whereas in antisense lines PME activity was decreased by up to 38%. PME isoform analysis indicated that the PEST1 gene encoded one isoform of PME. Analysis of cell walls from tubers from the over-expressing lines indicated that the changes in PME activity resulted in a decrease in pectin methylation. Analysis of processed tuber texture demonstrated that the reduced level of pectin methylation in the over-expressing transgenic lines was associated with a firmer processed texture. Thus there is a clear link between PME activity, pectin methylation and processed tuber textural properties.
Project description:'Potato is particularly vulnerable to increased temperature, considered to be the most important uncontrollable factor affecting growth and yield. Here we describe an acquired thermotolerance response in potato, whereby treatment at a mildly elevated temperature (''acclimated'') primes the plant for more severe heat stress compared to control (''non-acclimated'') plants. We define the time course for acquiring thermotolerance and demonstrate that light is essential for the process. Physiological, transcriptomic and metabolomic approaches were employed to elucidate potential mechanisms that underpin the acquisition of heat tolerance and indicate a role for cell wall modification, auxin and ethylene signalling, and chromatin remodelling in acclimatory priming.'
Project description:'Potato is particularly vulnerable to increased temperature, considered to be the most important uncontrollable factor affecting growth and yield. Here we describe an acquired thermotolerance response in potato, whereby treatment at a mildly elevated temperature (''acclimated'') primes the plant for more severe heat stress compared to control (''non-acclimated'') plants. We define the time course for acquiring thermotolerance and demonstrate that light is essential for the process. Physiological, transcriptomic and metabolomic approaches were employed to elucidate potential mechanisms that underpin the acquisition of heat tolerance and indicate a role for cell wall modification, auxin and ethylene signalling, and chromatin remodelling in acclimatory priming. This experiment identifies changes in transcript level were measured over a time course (0, 2, 6, 12 h) during the period of acquisition of thermotolerance following transfer from 18 °C (non-acclimated) to 25 °C (acclimated). Related experiment (E-MTAB-5857) looks to understand the mechanisms by which acclimation results in protection of leaves at extreme temperature; gene expression patterns were determined in leaves from acclimated and non-acclimated plants which were subsequently transferred to 40 °C and compared during a 48 h time course (2, 6, 12, 24 h).'
Project description:Nucleosomes must be deacetylated behind elongating RNA polymerase II to prevent cryptic initiation of transcription within the coding region. RNA polymerase II signals for deacetylation through methylation of histone H3 lysine 36 (H3K36) which provides the recruitment signal for the Rpd3S deacetylase complex. Recognition of methyl-H3K36 by Rpd3S requires the chromodomain of its Eaf3 subunit. Paradoxically, Eaf3 is also a subunit of the NuA4 acetyltransferase complex yet NuA4 does not recognize methyl H3K36 nucleosomes. We found that methyl H3K36 nucleosome recognition by Rpd3S also requires the PHD domain of its Rco1 subunit. Thus, the coupled chromo and PHD domains of Rpd3S specifies recognition of the methyl H3K36 mark; demonstrating the first combinatorial domain requirement within a protein complex to read a specific histone code.
Project description:Michelle N. Arbeitman, Eileen E. M. Furlong, Farhad Imam, Eric Johnson, Brian H. Null, Bruce S. Baker, Mark A. Krasnow, Matthew P. Scott, Ronald W. Davis and Kevin P. White. Gene Expression During the Life Cycle of Drosophila melanogaster, Science, 297: 2270-2275, 2002. This work can be accessed from http://www.sciencemag.org/cgi/content/full/297/5590/2270. The abstract of this paper: Molecular genetic studies of Drosophila melanogaster have led to profound advances in understanding the regulation of development. Here we report gene expression patterns for nearly one-third of all Drosophila genes during a complete time course of development. Mutations that eliminate eye or germline tissue were used to further analyze tissue-specific gene expression programs. These studies define major characteristics of the transcriptional programs that underlie the life cycle, compare development in males and females, and show that large-scale gene expression data collected from whole animals can be used to identify genes expressed in particular tissues and organs or genes involved in specific biological and biochemical processes.
Project description:Contains a collection of wildtype Saccharomyces cerevisiae strains for estimating the biological variation. Wildtypes are obtained from the "yeast wildtypes - platereader, wt pool bkg set" HybSet, by randomly taking 100 wt vs. refpool and 100 refpool vs. wt hybridizations.