I am interested in understanding the origins and maintenance of plant diversity in tropical forests. My research focuses on the phylogenetics and character evolution of members of the order Piperales, one of the basalmost lineages of angiosperms. My studies on character evolution have focused on the evolution of flowers in the perianthless Piperales and the genetics of flower development in Aristolochiaceae. My phylogenetic studies have focused on the genus Piper, one of the largest genera of flowering plants.
Flower development in Aristolochia
My studies on the genetics of flower development of Aristolochia have given interesting insights into the evolution of the ABC model outside the eudicots and monocots. I am investigating the role of floral identity genes in the production of Aristolochia's unique perianth morphology. Specifically, I have focused on the petal and stamen identity genes, APETALA3 (AP3) and PISTILLATA (PI). Using in situ mRNA hybridization, I showed that shifts in AP3 and PI expression in Aristolochia do not produce homeotic changes in the perianth, and most probably these genes have been co-opted for novel functions. I am expanding this comparative expression analysis to a broad sample of Aristolochia species native from Brazil, in order to evaluate the role of AP3 and PI in the large flower diversification exhibited by the genus. To evaluate the implications of the gene expression patterns observed in Aristolochia, I plan to conduct functional analysis by exploring the utility of virally-induced gene silencing (VIGS).
Phylogenetics of Piper
My studies on the phylogenetic relationships of the genus Piper have provided a robust phylogenetic framework to test hypothesis about character evolution and clade diversification. Piper is distributed in the tropics around the world, however it is most diverse in the Neotropics. We can recognize four phytogeographic assemblages of neotropical Piper: Central America, the Andes, the Amazonia and the Atlantic Forest of Brazil (AFB). I am currently studying the species diversity in the AFB, a region greatly endangered as only 8% of its original coverage is left.