Research

Meta-omics of a model lichen symbiosis

Lichens, the archetypal fungal-algal symbiosis, present a major exception to our understanding of how multicellularity works. Lichens are made of multiple unrelated lineages of microbes: different fungi, unicellular algae, and bacteria. Together—and only together—they can form elaborate three-dimensional bodies, which look nothing like individual symbionts.

In my project, I use metagenomics and metatrnscriptomics to identify molecular mechanisms behind the lichen symbiosis.

Using metagenomics to study lichen symbiosis

The goal of my PhD project was to study the give-and-take of different symbionts into the lichen symbiosis. My specific focus was on lesser-studied members of the symbiosis: lichen-associated yeasts and bacteria. I used lichen metagenomic data to obtain and analyze genomes of individual symbionts. Based on the genomes, I generated hypotheses about functional roles of different symbionts. Some of the hypotheses I tested in the lab using a novel digital-droplet PCR protocol.

Lichens and Conservation Biology

During my MSc and BSc time, I studied lichens not as symbiotic systems, but as individual members of their ecosystems. My focus was on the overlap of lichenology and conservation biology. What are the ways of protecting rare lichens? How lichens react to human-caused disturbances? How can we use lichens for ecological surveys and ecosystem-level conservation?

My MSc thesis is about a globally rare lichen species, Boreal Felt Lichen (Erioderma pedicellatum). The thesis and a paper based on it, present the first detailed report of the newly discovered Asian population of the species. I describe the ecology and extent of occurrence of the Asian population, and evaluate the threats the species is facing there. This project was a product of collaboration between three labs in two countries: the lichen group at the St. Petersburg University, the Pacific Institute of Geography, and Swiss Federal Institute for Forest, Snow and Landscape Research.

My BSc thesis compared lichen communities on aspen trees in three nature reserves in Russia. I collected and identified hundreds of lichen specimens and explored how the species composition of lichen communities depends on environmental factors. My focus was on how human-caused disturbances affect lichen communities, and on so-called indicator species: species that can be used to monitor the conditions of the ecosystems. The list of lichen species new to the Novgorod Region I identified during this work was published as my first first-author paper (see publications).

During my time at the St. Petersburg University, I participated in a number of other projects related to:

1. Lichen diversity of several regions of Russia (publishing additions to lichen floras and collecting information on newly reported species)
2. Conservation biology of lichens (surveys of endangered lichen species and lichen diversity in nature reserves).

A lichen and a lichen metagenome