Abstract
The Brassicaceae, including Arabidopsis thaliana and Brassica crops, is unmatched among plants in its wealth of genomic and functional molecular data and has long served as a model for understanding gene, genome, and trait evolution. However, genome information from a phylogenetic outgroup that is essential for inferring directionality of evolutionary change has been lacking. We therefore sequenced the genome of the spider flower (Tarenaya hassleriana) from the Brassicaceae sister family, the Cleomaceae. By comparative analysis of the two lineages, we show that genome evolution following ancient polyploidy and gene duplication events affect reproductively important traits. We found an ancient genome triplication in Tarenaya (Th-α) that is independent of the Brassicaceae-specific duplication (At-α) and nested Brassica (Br-α) triplication. To showcase the potential of sister lineage genome analysis, we investigated the state of floral developmental genes and show Brassica retains twice as many floral MADS (for minichromosome maintenance1, AGAMOUS, DEFICIENS and serum response factor) genes as Tarenaya that likely contribute to morphological diversity in Brassica. We also performed synteny analysis of gene families that confer self-incompatibility in Brassicaceae and found that the critical serine receptor kinase receptor gene is derived from a lineage-specific tandem duplication. The T. hassleriana genome will facilitate future research toward elucidating the evolutionary history of Brassicaceae genomes.
Highlights
Studies of the model plant Arabidopsis thaliana and its close relatives in the Brassicaceae family have provided fundamental insight into the processes and patterns of plant evolution and function (Koornneef and Meinke, 2010; Hu et al, 2011; Wang2814 The Plant Cell key traits (Edger and Pires, 2009; Flagel and Wendel, 2009)
To fully exploit the fundamental trait and genome insights garnered from Brassicaceae systems and improve synteny analyses to more distant crops, we report the genome sequencing and analysis of Tarenaya hassleriana from the Brassicaceae sister family Cleomaceae
For T. hassleriana, 86, 83, and 85% of the proteincoding genes were homologous to the genes in the A. thaliana, A. lyrata, and B. rapa genomes, respectively. By making these comparisons of Tarenaya versus A. thaliana, A. lyrata, and B. rapa genomes (Figure 3), we found significant, 3:2, 3:2, 3:4, 3:5, and 3:6 homologous patterns, respectively, which is consistent with the polyploid history of the species
Summary
Studies of the model plant Arabidopsis thaliana and its close relatives in the Brassicaceae family have provided fundamental insight into the processes and patterns of plant evolution and function (Koornneef and Meinke, 2010; Hu et al, 2011; Wang2814 The Plant Cell key traits (Edger and Pires, 2009; Flagel and Wendel, 2009). Most of the 300 Cleomaceae species are restricted to the semitropics and arid desert regions and lack a genetic pollen-pistil SI system, whereas most of the 3700 Brassicaceae species largely radiated into cold temperate regions and possess a genetically regulated SI system (Guo et al, 2011) Another striking distinction is in floral symmetry: Cleomaceae have mostly monosymmetric flowers and Brassicaceae have mostly disymmetric flowers (Endress, 1999; Patchell et al, 2011). The Cleomaceae species we sequenced is T. hassleriana, often referred to as the spider flower, which is widely grown as an ornamental species and used as an educational model (Marquard and Steinback, 2009). This species was formerly named Cleome hassleriana (often erroneously labeled as Cleome spinosa), but the genus Cleome has undergone recent taxonomic revisions (Iltis and Cochrane, 2007)
Sign-in/Register to view highlights & summary 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.
