Research

In the Marks Lab, we investigate how plants survive and adapt to extreme environments, with a specific focus on desiccation tolerance—the ability to withstand nearly complete water loss. We work with a wide range of plants and use comparative methods to understand the evolution and ecology of desiccation tolerance.

Our research spans multiple scales of biological organization, from molecular mechanisms to ecosystem dynamics, and uses tools ranging from field ecology to high-throughput genomics. As a result, research in our lab is dynamic and varied--we can sometimes be found hiking across rocky landscapes collecting eco-physiological data, at other times we're decked out in lab coats and PPE extracting and manipulating nucleic acids, and on other days we might be tucked away behind our screens developing bioinformatic pipelines. The diversity of approaches we employ mirrors what we hope to cultivate in our working group. We celebrate diversity in all its forms and advocate for the inclusion of marginalized peoples and perspectives in science.

Decolonizing science

We are committed to building an equitable and inclusive plant science community by broadening participation, decolonizing research practices, and promoting global collaborations. Our recent analyses have revealed persistent inequities in plant science that underscore the need for systemic change (Marks et al., 2021, Nature Plants and Marks et al., 2023, PNAS). Through grass roots collaborations, multilateral initiatives, and unconventional practices we try to learn from and empower underrepresented researchers worldwide.

Evolution of desiccation tolerance

Desiccation tolerance has evolved independently and recurrently in diverse plant lineages, offering a powerful framework for studying convergent evolution. We explore how selective pressures in arid and seasonally dry environments have driven the emergence of desiccation tolerance via the activation of similar physiological and molecular mechanisms. Our recent work in resurrection grasses revealed how conserved pathways, including protective proteins and metabolites, underpin tolerance across related species (Marks et al., 2024, Nature Plants). These studies provide insight into how evolutionary constraints and ecological pressures shape complex traits.

Local adapation

Natural variation within a single species can contribute to local adaptation. Using population genomics, transcriptomics, common garden experiments, and field observations, we examine how plants balance tolerance with fitness across environmental gradients of aridity. We recently found that in the resurrection grasses, Microchloa afra, higher-order polyploids dominate in more xeric habitats and exhibit enhanced desiccation tolerance (Marks et al., 2024, Journal of Experimental Botany). We suspect that this is due increased production of protective compounds enabled by gene duplication and novel regulatory networks in polyploids. it begs the question--does natural selection in different environments interface with genome duplication to facilitate rapid local adaption?

Community ecology and symbiosis

Survival in challenging and extreme habitats often relies on complex ecological networks and symbioses. We investigate how community dynamics and microbial associations influence resilience in desiccation-tolerant plants. Work in collaboration with our colleagues in South Africa on the root-associated microbiome of Myrothamnus flabellifolia indicated that microbial interactions can increase stress tolerance by modulating nutrient uptake and defense pathways (Tebele et al., 2023, Plant and Soil). By integrating field experiments with metagenomics, we are exploring how plant-microbe interactions support water stress tolerance.

Physiology and functional traits

Understanding how plants tolerate desiccation also requires connecting genetic mechanisms to whole-plant function. Physiology and cell biology are critical links in this process. Our lab is exploring imaging techniques, gas exchange measurements, and biochemical assays to study traits such as stomatal dynamics, water use efficiency, and photosynthesis during extreme dehydration. These studies provide a mechanistic framework for understaning desiccation tolerance.

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