Developmental and environmental signals induce distinct histone acetylation profiles on distal and proximal promoter elements of the C4-Pepc gene in maize.

The maize C(4)-Pepc gene is expressed in an organ- and cell-type-specific manner, inducible by light and modulated by nutrient availability and the metabolic state of the cell. We studied the contribution of histone acetylation at five lysine residues to the integration of these signals into a graduated promoter response. In roots and coleoptiles, where the gene is constitutively inactive, three of the five lysines were acetylated and the modifications showed unique patterns with respect to their distribution on the gene.

Developmental information but not promoter activity controls the methylation state of histone H3 lysine 4 on two photosynthetic genes in maize.

We have investigated the establishment of histone H3 methylation with respect to environmental and developmental signals for two key genes associated with C4 photosynthesis in maize. Tri-methylation of histone H3 lysine 4 (H3K4) in roots and leaves was shown to be controlled by autonomous cell-type-specific developmental signals that are independent of illumination and therefore independent of the initiation of transcription. Di- and mono-methylation of H3K4 act antagonistically to this process.

Chromatin immunoprecipitation: optimization, quantitative analysis and data normalization.

Background: Chromatin remodeling, histone modifications and other chromatin-related processes play a crucial role in gene regulation. A very useful technique to study these processes is chromatin immunoprecipitation (ChIP). ChIP is widely used for a few model systems, including Arabidopsis, but establishment of the technique for other organisms is still remarkably challenging.

Illumination is necessary and sufficient to induce histone acetylation independent of transcriptional activity at the C4-specific phosphoenolpyruvate carboxylase promoter in maize.

Expression of the C4-specific phosphoenolpyruvate carboxylase (C4-PEPC) gene in maize (Zea mays) is regulated in a tissue-specific manner, but affected by light and nutrient availability. We manipulated these stimuli in a combinatorial manner and analyzed concomitant changes in histone acetylation of the nucleosomes associated with the C4-PEPC gene in relation to transcriptional activity and steady-state mRNA levels. Whereas the transition from the lowest activity to an intermediate activity was observed in the absence of histone acetylation, the light-induced boost to full activity was associated with strong enhancement of the acetylation of both histones H3 and H4 limited to the gene region.