title: How many genes are there in plants (... and why are they there)?
abstract: Annotation of the first few complete plant genomes has revealed that plants have many genes. For Arabidopsis, over 26,500 gene loci have been predicted, whereas for rice, the number adds up to 41,000. Recent analysis of the poplar genome suggests more than 45,000 genes, and partial sequence data from Medicago and Lotus also suggest that these plants contain more than 40,000 genes. Nevertheless, estimations suggest that ancestral angiosperms had no more than 12,000-14,000 genes. One explanation for the large increase in gene number during angiosperm evolution is gene duplication. It has been shown previously that the retention of duplicates following small- and large-scale duplication events in plants is substantial. Taking into account the function of genes that have been duplicated, we are now beginning to understand why many plant genes might have been retained, and how their retention might be linked to the typical lifestyle of plants.
authors.affiliation: Department of Plant Systems Biology, Flanders Interuniversity Institute for Biotechnology (VIB), Ghent University, Technologiepark 927, B-9052 Ghent, Belgium.
authors.forename: Lieven
authors.initials: L
authors.lastname: Sterck
authors.forename: Stephane
authors.initials: S
authors.lastname: Rombauts
authors.forename: Klaas
authors.initials: K
authors.lastname: Vandepoele
authors.forename: Pierre
authors.initials: P
authors.lastname: Rouzé
authors.forename: Yves
authors.initials: Y
authors.lastname: Van de Peer
mesh_terms: D017343:Genes, Plant; D016366:Open Reading Frames / Q000235:genetics