About Medicinal Plant Genomics Resource

Natural products from plants serve as rich resources for drug development with almost 100 plant-derived compounds in clinical trials in 2007. Plant derived natural products have had a profound and lasting impact on human health and include compounds successfully used for decades such as digitalis, Taxol, vincristine, and morphine isolated from foxglove, periwinkle, yew, and opium poppy, respectively. The enormous structural diversity and biological activities of plant-derived compounds suggest that additional, medicinally relevant compounds remain to be discovered in plants. While plant natural products continue to be a prime target for drug development, as evidenced by the number of ongoing clinical trials, the clinical potential of these compounds is often curtailed due to low production levels in plant species. For example, use of the blockbuster drug Taxol almost stopped in the early 1990's because the primary source, yew tree bark, could not be used as a sustainable source of the drug. In this particular instance, a Taxol precursor happened to be more readily available in a renewable part of the tree, and a semi-synthetic protocol could be developed to convert it into the drug. While fortuitous, more generalized solutions, such as metabolic engineering of effective plant and microbial production platforms, are urgently needed to ensure that the wealth of bioactive compounds found in plants enter the clinical pipeline and find widespread use in medicine. High throughput transcriptome sequencing approaches provide a straightforward means for accessing the gene content in organisms with large genomes (i.e. > 100 Mb). Essentially any tissue (independent of genome size and availability of genetic or molecular tools in the organism) can be used to generate cDNAs from mRNA populations and sequenced to generate Expressed Sequence Tags (ESTs) that are assembled into a non-redundant set of sequences (contigs and singleton ESTs) to represent the transcriptome. The transcriptome sequences are then annotated for putative function using a suite of bioinformatic approaches such as sequence searches of protein databases, motif/domain identification, biochemical pathway mapping, and subcellular localization predictions. Transcript abundance data can also be used to provide in-depth expression profiles of individual genes on a per tissue/treatment basis. The deduced function, coupled with expression frequency, can facilitate identification of candidate genes pertinent to the pathway of interest as well as non-pathway targets (e.g. primary/intermediary metabolism) whose expression is consistent with synthesis of compounds. Medicinal Plant Genomics Website is maintained and hosted by the Buell Lab in the Plant Biology Department at Michigan State University.