Research in Villarreal lab focuses broadly on the three hottest topics in evolutionary biology: biodiversity, climate change and food security.
The diversity aspect tackles the symbiotic interactions between plants and a wide array of organisms. Our four recently funded initiatives aim to better understand the diversity and the functional genomics of plants and their associated nitrogen-fixing bacteria (cyanobacteria). Specifically, cyanobacteria that are associated with tropical plants (especially hornworts and cycads) and boreal-arctic cryptogams (lichens, mosses and liverworts). The overarching objective is to understand the temporal and spatial diversity of plants, their associated symbionts and the genomic underpinnings of these associations. The arctic research is relevant under the most important threat of the century: man-made climate change: How organisms and associated symbionts are distributed and how they will adapt to such rapid changes?
The last topic of interest is the diversification of hornworts and evolution of key traits such cyanobacterial symbiosis and the biophysical carbon concentrating mechanisms (CCM, .e.g pyrenoids) in hornworts. Each hornwort has a symbiotic association with cyanobacteria and the need to understand this symbiosis is key to further engineer this pathway into higher plants. In addition, pyrenoids are ubiquitous among algae and help to increase the CO2 around the Rubisco active sites. Among land plants, hornworts are the only one with pyrenoids and my lab is developing genomic resources to understand the biology of the hornwort pyrenoid and hoping to eventually incorporate the hornwort CCM into crop plants.
We focus our research on bryophytes and gymnosperms, but recently our endeavour have also moved into the study of lichens.
Our lab uses a vast number of tools to achieve our research objectives. Combination of such tools includes and are not limited to herbarium taxonomy, electron microscopy, DNA sequencing, in-vitro culturing, genomic and transcriptomic data as well as phylogenetic analyses. Overall, we are working to aid in the understanding of evolutionary processes that generates the rich diversity of plants and their symbionts in tropical and arctic regions.
Bryophytes (liverworts, mosses and hornworts) are the second largest group of plants (nearly 20,000 species!) and are the closest extant relatives of early land colonizers ca. 500 millions of years ago. Bryophytes are found in all continents and are capable of growing on bare soil, rocks, tree trunks as well as the leaves of vascular plants. Symbiosis with cyanobacteria can be endophyte-obligates (every species of hornworts and the liverwort order Blasiales) or found epiphytic on mosses, leafy and thalloid liverworts. In both cases, the contribution to the nitrogen budget is of great ecological significance, especially that of the boreal forests.
Lichens are a fascinating assembly of organisms: one or two (or more?) fungi with a green alga (e.g. Trebouxia, Asterochloris) and/or cyanobacteria (e.g. Nostoc, Stigonema). Additionally, there is a large number of bacteria, and potentially viruses, that are associated to lichens. Our lab focuses on lichen of the woodland variety, including Stereocaulon (cyanolichen), Cladonia stellaris, Cladonia mitis and the charismatic reindeer lichen, Cladonia rangiferina. These studies goes from phylogenetic investigations of each symbiont to an in-depth analysis of virus functional diversity.
Cycads are a group of gymnosperms with high ornamental value and a rich fossil record since the Permian period (290 millions of years ago). Each species within this group interacts with cyanobacteria and non-mycorrhyzal fungi in their “coralloid roots”. Our research focuses on the endemic Panamanian species that fall within the genus Zamia with emphasis on the epiphytic, Z. pseudoparasitica as well as related terrestrial species.