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Marc Zabeau

Publications and source records attributed to Marc Zabeau.

4 recordsLinked to original sources

A functional genomics approach toward the understanding of secondary metabolism in plant cells.

Despite the tremendous importance of secondary metabolites for humans as for the plant itself, plant secondary metabolism remains poorly characterized. Here, we present an experimental approach, based on functional genomics, to facilitate gene discovery in plant secondary metabolism. Targeted metabolite analysis was combined with cDNA-amplified fragment length polymorphism-based transcript profiling of jasmonate-elicited tobacco Bright yellow 2 cells. Transcriptome analysis suggested an extensive jasmonate-mediated genetic reprogramming of metabolism, which correlated well with the observed shifts in the biosynthesis of the metabolites investigated. This method, which in addition to transcriptome data also generates gene tags, in the future might lead to the creation of novel tools for metabolic engineering of medicinal plant systems in general.

Acetates↗

Transcriptome analysis during cell division in plants.

Using synchronized tobacco Bright Yellow-2 cells and cDNA-amplified fragment length polymorphism-based genomewide expression analysis, we built a comprehensive collection of plant cell cycle-modulated genes. Approximately 1,340 periodically expressed genes were identified, including known cell cycle control genes as well as numerous unique candidate regulatory genes. A number of plant-specific genes were found to be cell cycle modulated. Other transcript tags were derived from unknown plant genes showing homology to cell cycle-regulatory genes of other organisms. Many of the genes encode novel or uncharacterized proteins, indicating that several processes underlying cell division are still largely unknown.

Cell Cycle↗

The hidden duplication past of Arabidopsis thaliana.

Analysis of the genome sequence of Arabidopsis thaliana shows that this genome, like that of many other eukaryotic organisms, has undergone large-scale gene duplications or even duplications of the entire genome. However, the high frequency of gene loss after duplication events reduces colinearity and therefore the chance of finding duplicated regions that, at the extreme, no longer share homologous genes. In this study we show that heavily degenerated block duplications that can no longer be recognized by directly comparing two segments because of differential gene loss, can still be detected through indirect comparison with other segments. When these so-called hidden duplications in Arabidopsis are taken into account, many homologous genomic regions can be found in five to eight copies. This finding strongly implies that Arabidopsis has undergone three, but probably no more, rounds of genome duplications. Therefore, adding such hidden blocks to the duplication landscape of Arabidopsis sheds light on the number of polyploidy events that this model plant genome has undergone in its evolutionary past.

Arabidopsis↗