The evolutionary origin of the Arabidopsis receptor kinase THESEUS1 and its function in plant cell wall integrity maintenance
Authors
Steven T. W. Zwartkruis [1]
Nelly K. Braun [1]
Wiebke Häger [1]
Tereza Tichá [1]
Vivien Klein [1]
Christine Ziegler [2]
Gregor Madej [2]
Martijn L. Vandegehuchte [1]
Thorsten Hamann [1]
Keywords
Plant cell wall; cell wall integrity maintenance; receptor kinase; signaling; plant stress response
Abstract
Plants actively monitor the state of their cell walls and adapt their structure and composition as needed. This cell wall integrity maintenance is crucial during development and the response to biotic- or abiotic stress, and relies on THESEUS1 (THE1), a receptor kinase. Mutations in THE1 lead to changes in cell wall stiffness, and altered jasmonic acid, abscisic acid and lignin levels in response to stress conditions. However, little is known about the mechanism by which THE1 is activated and very few downstream components have been characterized. To address this knowledge gap, we have generated a set of wild type and the1 loss-of-function plants expressing full length, truncated, and kinase-dead versions THE1-GFP constructs. These lines were tested for tolerance to drought and powdery mildew to find the biological relevance of THE1. We also used these mutant lines to study which domains are essential for the activation of downstream responses, as well as for intracellular localization studies. We performed a GFP-pulldown experiment to identify novel interaction partners of THE1, and discuss the potential proteolytic regulation of THE1. Finally, we find that THE1 is present in all seed plants except for the grasses. This deep conservation in the angiosperm lineage and its role in maintaining CWI during stress makes THE1 an interesting topic of study, providing leads for the knowledge-based development of resilient plant varieties.
Funding
Thorsten Hamann and Christine Ziegler acknowledge funding from ERC SYNERGY grant HYDROSENSING (ERC10118769). Thorsten Hamann acknowledges funding from NFR grant WALLINTEGRITY (NFR315325).