Abstract
BackgroundThe Floral Genome Project was initiated to bridge the genomic gap between the most broadly studied plant model systems. Arabidopsis and rice, although now completely sequenced and under intensive comparative genomic investigation, are separated by at least 125 million years of evolutionary time, and cannot in isolation provide a comprehensive perspective on structural and functional aspects of flowering plant genome dynamics. Here we discuss new genomic resources available to the scientific community, comprising cDNA libraries and Expressed Sequence Tag (EST) sequences for a suite of phylogenetically basal angiosperms specifically selected to bridge the evolutionary gaps between model plants and provide insights into gene content and genome structure in the earliest flowering plants.ResultsRandom sequencing of cDNAs from representatives of phylogenetically important eudicot, non-grass monocot, and gymnosperm lineages has so far (as of 12/1/04) generated 70,514 ESTs and 48,170 assembled unigenes. Efficient sorting of EST sequences into putative gene families based on whole Arabidopsis/rice proteome comparison has permitted ready identification of cDNA clones for finished sequencing. Preliminarily, (i) proportions of functional categories among sequenced floral genes seem representative of the entire Arabidopsis transcriptome, (ii) many known floral gene homologues have been captured, and (iii) phylogenetic analyses of ESTs are providing new insights into the process of gene family evolution in relation to the origin and diversification of the angiosperms.ConclusionInitial comparisons illustrate the utility of the EST data sets toward discovery of the basic floral transcriptome. These first findings also afford the opportunity to address a number of conspicuous evolutionary genomic questions, including reproductive organ transcriptome overlap between angiosperms and gymnosperms, genome-wide duplication history, lineage-specific gene duplication and functional divergence, and analyses of adaptive molecular evolution. Since not all genes in the floral transcriptome will be associated with flowering, these EST resources will also be of interest to plant scientists working on other functions, such as photosynthesis, signal transduction, and metabolic pathways.
Highlights
The Floral Genome Project was initiated to bridge the genomic gap between the most broadly studied plant model systems
Identification of cDNA clones for finished sequencing has been aided by efficient sorting of Expressed Sequence Tag (EST) sequences into putative gene families based on whole Arabidopsis/rice proteome comparison
Proof-of-concept: EST coverage Relative to the Gene Ontology (GO) functional classification, the Floral Genome Project (FGP) is detecting new, translated sequences with astonishing similarity to frequencies known for the entire Arabidopsis transcriptome
Summary
The Floral Genome Project was initiated to bridge the genomic gap between the most broadly studied plant model systems. The genome sequences of Arabidopsis [1] and rice [2,3] have stimulated great advances throughout the plant sciences Comparisons of these eudicot and monocot genomes have provided many insights into the genome characteristics and evolutionary histories of both lineages [e.g. [4,5,6]], and comparisons involving additional species are generating a more global picture of angiosperm genome evolution [7,8,9] These multispecies comparisons, and comparative plant sciences more generally, have been aided by the well-supported understanding of evolutionary relationships among flowering plants that has emerged over the last decade [e.g. Increased genomic resources for phylogenetically diverse plant species will lead to a better understanding of plant genome evolution, the diversification of gene families, and the origins of reproductive characteristics common to all flowering plants
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
