CeBiTec Colloquium


Monday, July 12th 2010, 17 c.t.


G2-104, CeBiTec Building


Prof. Dr. Angelika Mustroph

Lehrstuhl Pflanzenphysiologie, Universität Bayreuth


Actual methods for gene expression analysis – from gene expression changes in different cell types to a cross-species comparison

  Microarray analysis is a large-scale technology to study the genome-wide response of organisms to environmental changes such as oxygen deficiency stress. Traditionally, microarrays are used to monitor changes in the steady-state abundance of total cellular mRNAs: the transcriptome. Many transcriptome studies have been published for the model plant Arabidopsis thaliana reporting changes in gene expression on the whole-plant level or on a single organ. Here, I will present analyses of transcript adjustments to environmental changes aimed to provide a better resolution, focusing on the example of plant responses to low oxygen stress (hypoxia). First, we developed a technique to isolate mRNA not only from whole organs, but also from different cell types of an organ. This technique is based on the immunopurification of FLAG-tagged ribosomes expressed in specific cell types of Arabidopsis, thus enabling the isolation of mRNAs associated with ribosomes, which we refer to as the translatome. By evaluation of translatomes of 21 root and shoot cell type populations in control and hypoxia-stressed seedlings, we discovered 49 genes co-induced by hypoxia across diverse cell types, while cell-type specific differences were most evident in mRNAs that were reduced by hypoxia (Mustroph et al., 2009, PNAS 106:18843-18848; Subsequently, we expanded our gene expression analysis by comparing the transcriptomic response of Arabidopsis to low-oxygen stress to other plant species as well as animals, fungi and bacteria (Mustroph et al., 2010, Plant Physiology 152:1484-1500). The evidence of common metabolic adaptations contrasted with distinctions in signal transduction across organisms and kingdoms.

Prof. Dr. Karl-Josef Dietz