A Cross-Kingdom Comparison for the Identification of Novel Wound Response Proteins

: A Parallel Study in Zebrafish and Arabidopsis

Abstract

The biology of wound repair in plants and animals is highly divergent, in part,
because plants are immotile. Held by a cage-like cell wall, the plant is neither
able to move away from danger nor direct an immune cell defence force to
the site of injury like an animal can. However, despite the massive
phylogenetic distance between them, tissue repair is so essential to their
survival that these two phyla will have acquired common strategies, some
from shared ancestors and others by parallel evolution, that enable sealing
of the epidermal barrier layer and protection in the face of infection.
Here I have undertaken a direct comparison of the wound response in the
model plant, Arabidopsis thaliana, versus the model animal, zebrafish.
Beginning with a parallel proteomic study, I focus specifically on identifying
novel parallel mechanisms that may be fundamental but are currently
understudied. I then explore the leads from this comparison, exploiting the
strengths of these model organisms, and screen novel candidates for
function in the wound response. I show in fish that, just as in plants, txn and
rnaset2 are expressed at the wound site, and that rnaset2 is involved in
apoptotic cell clearance by macrophages. In plants, I find that three BIP
family chaperones, and two proteases APA1 and RD21B are upregulated
following wounding, and search for parallel functions versus their animal
counterparts. This study shows that combining the knowledge of these two
fields may bear fruit and accelerate discovery of novel targets, both for
therapeutic intervention to improve healing in the clinic, and for enhancing
crop resistance in agriculture.

Date of Award	1 Oct 2024
Original language	English
Awarding Institution	University of Bristol
Supervisor	David Stephens (Supervisor) & Paul B Martin (Supervisor)