Polyploidy genome evolution in the Nicotiana genus section Suaveolentes.
Nicotiana is a genus with more than 77 described species grouped in 13 sections. 40% of the Nicotiana species are allotetraploids, of which the most popular examples are N. tabacum (2n = 4x = 48) and N. benthamiana (2n = 4x = 38). N. benthamiana is a native species of Western Australia from the Suaveolentes section with an estimated age of 9-10 MY. The recent whole genome sequencing of this species has reported ~60,000 genes (Niben v1.0.1). The comparison of the N. benthamiana gene space with a more recent polyploid as N. tabacum (~73,000 genes) and its diploid ancestors N. sylvestris and N. tomentosiformis (~37,000 genes) supports the hypothesis of massive gene lost during the polyploid-to-diploidization process. The goal of this project is to study the genome evolution of paleopolyploids such as N. benthamiana.
Figure 2: Diagram representing the pseudodiploidization process in Nicotiana benthamiana.