Patterns and Processes of Diploidization in Land Plants

Abstract

Most land plants are now known to be ancient polyploids that have rediploidized. This process of diploidization involves many changes in genome organization that ultimately restores bivalent chromosome pairing, disomic inheritance, and resolves dosage and other issues caused by genome duplication. Here, we provide an overview of the variety of mechanisms involved in diploidization as well as new analyses of pairing behavior and variation in gene fractionation across land plants. Overall, we find that lineage and WGD specific attributes influence the evolutionary outcomes of WGD and the process of diploidization in plant genomes. Ultimately, many of the mechanisms and forces driving diploidization remain to be discovered. Future research that leverages variation in the patterns and processes of diploidization will be able to advance our understanding of plant genome evolution and unlock the mysteries of diploidization.

SUPPLEMENTAL TABLES for Li et al. Patterns and Processes of Diploidization in Land Plants

Supplemental Table 1. Summary table of the frequency of strictly bivalent vs multivalent or a mix of bivalent and multivalent pairing in allo- or autopolyploids.

Supplemental Table 2. List of the fraction of genes retained from a WGD and the range and estimated median Ks value of each WGD analyzed.

Supplemental Table 3. Summary statistics of phylogenetic signal and linear and exponential fits before and after phylogenetically-corrected rate of post-WGD paralog loss in land plants.