Polyploids increase overall diversity despite higher turnover than diploids in the Brassicaceae

Abstract

Although polyploidy is widespread across the plant Tree of Life, its long-term evolutionary significance is still poorly understood. Here, we examine the effects of polyploidy in explaining the large-scale evolutionary patterns within angiosperms by focusing on a single family exhibiting extensive interspecific variation in chromosome numbers. We inferred ploidy from haploid chromosome numbers for 80% of species in the most comprehensive species-level chronogram for the Brassicaceae. After evaluating a total of 94 phylogenetic models of diversification, we found that ploidy influences diversification rates across the Brassicaceae. We also found that despite diversifying at a similar rate to diploids, polyploids have played a significant role in driving present-day differences in species richness among clades. Overall, in addition to highlighting the complexity in the evolutionary consequences of polyploidy, our results suggest that rare successful polyploids persist while significantly contributing to the long-term evolution of clades. Our findings further indicate that polyploidy has played a major role in driving the long-term evolution of the Brassicaceae and highlight the potential of polyploidy in shaping present-day diversity patterns across the plant Tree of Life.

Phylotranscriptomics Illuminates the Placement of Whole Genome Duplications and Gene Retention in Ferns

“…One of the major debates in the polyploid literature is the role of genome duplications in diversification. Polyploid plants have been suggested to diversify at faster rates than diploids ( Soltis et al, 2014a ; Tank et al, 2015 ; Landis et al, 2018 ; Román-Palacios et al, 2020 ; but see Mayrose et al, 2011 ; Arrigo and Barker, 2012 ; Mayrose et al, 2015 for contrasting results). Although we do not address diversification here, it is of note that the two inferred WGDs shared by the largest number of taxa are at the base of the most diverse fern clades.…”

Dissection of full-length transcriptome and metabolome of Dichocarpum (Ranunculaceae): implications in evolution of specialized metabolism of Ranunculales medicinal plants

“…In summary, this study demonstrates the effectiveness of high throughput full-length transcriptome sequencing, species and gene tree analyses, and gene/metabolite correlation analysis in elaborating gene expression and metabolic profiles, unearthing the hidden connections between transcriptome and metabolome, and clarifying key evolutionary facts with respect to the plants’ adaptibility in the capricious environments. Polyploidy is widespread across the plant Tree of Life ( Román-Palacios, Molina-Henao & Barker, 2020 ), which could play a major role in driving the long-term evolution of Ranunculaceae and related taxonomic groups and shaping present-day diversity patterns across Ranunculales. In addition to the structural genes of biosynthetic pathways, the associated TFs probably co-evolve to achieve the coordinate expression of biosynthetic genes.…”

Interactions between breeding system and ploidy affect niche breadth in Solanum

“…Solanum andreanum is both diploid and polyploid). A recent paper on Brassica species by Román-Palacios et al [ 37 ] showed that both classifications are mostly indistinguishable in trees with a lot of tips, which is the case of Solanaceae. In our dataset there are higher polyploids (6 x and 8 x , e.g.…”