Project Details
Projekt
Analysis of dynamic interactions of ROXYs, land plant-specific glutaredoxins, with TGA transcription factors during the evolution of land plants
Applicants
Dr. Nora Gutsche; Professorin Dr. Sabine Zachgo
Subject Area
Biochemistry
Term
from 2014 to 2021
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 251970190
Redox biochemistry is increasingly recognized as a crucial component of cellular signal processing in all types of organisms. Endogenous changes of oxidant levels are now known to contribute to cell fate decisions, such as proliferation, differentiation and apoptosis. Keeping the balance between damaging and adaptive processes mediated by oxidant levels is key to adaptation of life forms to changing biotic and abiotic environments, both throughout the life cycle of one organism and also on a larger scale during the evolution of organisms. Plants are sessile organisms and, in contrast to mobile animals, have to adjust to their environment being faced with challenges such as damage by pathogen attack or stress exposure by UV-light and draught. All plants possess CPYC and CGFS glutaredoxine (GRXs), glutathione-dependent oxidoreductase proteins, which are members the thioredoxin-fold superfamily. Like thioredoxins, GRXs act as antioxidants and have cysteine thiol disulphide exchange catalytic properties. At the time when plants conquered the land, about 470 MY ago, in the most basal land plants, the mosses, a novel land plant-specific GRX group, the CC-type GRXs, emerged. During the evolution of land plants, exclusively this CC-type GRX group expanded strongly coinciding with the formation of plants, which are composed of more complex organs and better adapted to a life on land. This raises the intriguing questions about the biochemistry of novel evolving redox signaling events and thiol switches and their specific functions during the evolution of land plants.The proposed SPP project focuses on investigating the function of the land plant-specific CC-type GRXs, ROXYs, and the underlying protein thiol switches during land-plant evolution. ROXY1 from Arabidopsis thaliana governs petal and anther development via interaction with the TGA transcription factor PERIANTHIA (PAN) in the nucleus. Given that ROXYs are land-plant specific, we aim to unravel the molecular function of ancestral ROXYs in a basal land plant, the livermoss Marchanita polymorpha, to understand how a land-plant specific group of GRXs and the associated thiol-switches and redox-processes have contributed to novel adaptations to a life on land. We showed that the protein interactions between ROXYs and TGAs as well as their redox-dependent DNA binding is highly conserved. We aim to compare the biochemical activities of ROXYs and TGAs from Arabidopsis (ROXY1, PAN) and Marchantia (MpROXY1/2, MpTGA1/2). By a combination of in vitro and in vivo approaches we aim to analyzed the determined nuclear thiol-switch in more detail and investigate how nuclear redox-processes contributed to the adaptations that made a terrestrial lifestyle possible.
DFG Programme
Priority Programmes
