Symbiosis Continuum
During my postdoctoral research in Nick Talbot's lab at The Sainsbury Laboratory, I investigated the nature of the lichen symbiosis. How is such a cross-kingdom partnership, which has evolved multiple times, initiated and maintained?
I used a combination of transcriptomics, genomics, and microscopy to investigate these questions, within the lichen study systems of Xanthoria parietina and Cladonia portentosa.
I conducted my PhD in Alan Prather's lab in the Department of Plant Biology and the Ecology, Evolutionary Biology and Behavior program at Michigan State University.
I investigated the latitudinal diversity gradient of lichens using a comparison of two methods; using herbarium collections data, and using my own field-sampled data along a latitudinal gradient in the Americas.
The raw herbarium collections data show a peak of lichen diversity in the mid-temperate latitudes, and not in the tropics. When we rarefied the herbarium specimen data to account for sampling bias, we found that lichenized fungi in the Americas do follow a latitudinal diversity gradient.
From the field study, sampling at 9 different latitudes from 11S to 61N, we have seen very high species richness and beta diversity of lichens in tropical forests versus temperate and boreal forests. Though only focusing on epiphytic lichen diversity at researcher height, this corroborates our results from the rarefied herbarium data.
The focus of my Master's Thesis work was on the ability of arbuscular mycorrhizal fungi to help their plant symbionts deal with salinity stress. I studied a mixture of native, invasive, and agricultural legumes in south Florida with a particular focus on the pine rockland ecosystem.
During my thesis tenure I had the opportunity to visit ICRISAT (International Crops Research Institute for the Semi-Arid Tropics) in Hyderabad, India. There I helped to study the impact of various field conditions on rhizobial bacteria and their symbiosis with crop legumes.
(pictured left)
A component of my thesis work is published here:
Scharnagl K, Sanchez V, von Wettberg E (2018) The impact of salinity on mycorrhizal colonization of a rare legume, Galactia smallii, in South Florida pine rocklands. BMC Research Notes 11:2