Publications
Model system: Flowering time
Plants have evolved the remarkable ability to time and tune key biological events in response to changes in their physical environment. For instance, many crop species depend on prolonged exposure to winter temperatures, known as "vernalization," to flower the following spring. This process allows plants to bloom when their pollinators are active. But as extreme weather disrupts these essential cold periods, many plants may fail to meet their vernalization requirements and struggle to flower within their proper time frame. This poses an existential threat to global biodiversity and agricultural productivity.
What do we know about temperature-dependent flowering? Quite a lot, actually. In the model plant Arabidopsis thaliana, temperature-dependent flowering is controlled by the transcriptional state of a critical gene locus known as FLOWERING LOCUS C (FLC). In warm temperatures, proteins such as SUPPRESSOR OF FRIGIDA 4 (SUF4), FRIGIDA (FRI), and other FLC regulators recruit chromatin remodelers (PAF/SWR1 complex) to transcriptionally activate FLC, thereby suppressing flowering. As winter approaches, FLC transcription must be turned off to prepare the plant for spring flowering. This process involves a new set of chromatin remodelers (PRC2 complex) and long non-coding RNAs (lncRNAs) to epigenetically silence FLC. Once temperatures rise again, the cold-induced silencing of FLC persists, establishing an epigenetic "memory of winter cold" that promotes the transition to flowering in spring. Despite this extensive knowledge, a major question remains: How do plant cells sense changes in seasonal temperatures to elicit these different regulatory responses at the FLC gene locus?
?
?
?
The Meyer Lab uses advanced cell imaging, molecular cell biology, and biochemistry techniques to investigate how intrinsically disordered proteins (IDPs) function as both thermal sensors and switches to regulate temperature-dependent flowering. IDPs are ideal candidates for such roles because their low-complexity domains allow for unique biophysical behaviors, including the ability to phase separate under defined environmental conditions into proteinaceous bodies called "biomolecular condensates". Moreover, IDPs are of interest because many of the proteins that regulate FLC are disordered or possess intrinsically disordered regions, with some already demonstrated to form temperature-dependent condensates. Thus, we hypothesize that plants use temperature-dependent IDP phase separation to concentrate or stabilize regulatory factors needed for the temperature-stimulated regulation of FLC. During prolonged periods of cold, these IDPs may fail to transition to their liquid phase, resulting in the inactivation of flowering repressors and preparing Arabidopsis plants for flowering when the temperature rises.
Condensate
No condensate