Genome Size Evolution in the Genus Genlisea – From Half of the A. thaliana Genome to the Twenty-fold

The monophyletic genus Genlisea, belonging to the carnivorous Lentibulariaceae family, is outstanding in several aspects. One is the strikingly different genome sizes between its species ranging from less than half of the Arabidopsis thaliana genome to more than 20-fold larger. Other peculiar aspects are a unique trapping system for carnivory and an extremely high rate of base substitution. Analysis of the Genlisea pygmaea (86 Mbp) and G. hispidula (1510 Mb) genomic sequence could allow us to test hypothetic reasons for rapid genome size shrinkage and expansion. Thus, de novo sequencing of the G. pygmaea genome, one of the smallest plant genomes reported so far, by the next generation sequencing (Illumina and 454 technologies) and its assembly under the guidance of the optical mapping data is performed. Comparative genomics including repetitive elements between G. pygmaea and G. hispidula allows addressing the relative contribution of various mutational forces that shaped those eudicot genomes in different manners. The outcome of these in silico analyses will be complemented by comparative chromosome painting in order to trace the evolution of the karyotypes of divergent Genlisea species.

In addition, the transcriptomes of aerial and subterraneous (trapping) organs of G. pygmaea and G. hispidula are sequenced to provide a first cue for studies of the genetic basis, differentiation and evolution of the unique trapping system of the genus. This will shed new light on the evolutionary strategies which these remarkable plants use to survive within nutrition-poor environments.