Abstract
Plant secondary metabolites are characterized by an enormous chemical
diversity and presently appoximately 100 000 of them have been isolated. They
include many high-value pharmaceuticals e.g. anticancer drugs. However, their
production is complicated due to the low contents in plants and cell cultures
or extremely complex chemical synthesis. Plant metabolic engineering has met
only limited success, in sharp contrast to microorganisms, since our knowledge
about the biosynthesis of secondary metabolites is still very limited.
Genetic maps of biosynthetic pathways are far from complete and the regulation
of these pathways is poorly understood. We designed a novel approach using
tobacco BY-2 cell culture as a model system, in which a cDNA-AFLP based
transcript-profiling technique is linked with targeted metabolic profiling of
plant cells to simultaneously identify genes involved in secondary metabolism
on a genome-wide scale. From the 20000 transcript tags visualized 591 were
jasmonate-modulated with different kinetics. Cluster analysis of expression
profiles showed that half of the genes were induced already after 1-4 hours.
These genes were of special interest since accumulation of metabolites started
after 12 hours of elicitation. No homology to a known sequence was found for
16% of the tags whereas 66% were similar to genes with a known function, and
18% revealed similarity to genes without an allocated function. Functional
analysis in transgenic cell lines is focused on genes encoding signal
transduction proteins, kinases, phosphatases and transcription factors as well
as those with unknown function. Besides identifying several novel genes, we
were able to characterize poorly understood branches of secondary metabolite
biosynthetic pathways in tobacco, leading to nicotine alkaloids and
phenylpropanoids, by using hyphenated analytical tools (GC-, HPLC-MS). The
great advantage of this novel technology platform is its universal application
to any plant or cell culture of interest without pre-existing gene sequence
databases.
| Original language | English |
|---|---|
| Publication status | Published - 2003 |
| MoE publication type | Not Eligible |
| Event | 7th International Congress Plant Molecular Biology - Barcelona, Spain Duration: 23 Jun 2003 → 28 Jun 2003 |
Conference
| Conference | 7th International Congress Plant Molecular Biology |
|---|---|
| Country/Territory | Spain |
| City | Barcelona |
| Period | 23/06/03 → 28/06/03 |