Periodic Reporting for period 1 - EPPIMAL (Charting the evolution of protein-protein interaction networks shaping plant metabolic adaptation to land)
Reporting period: 2023-02-01 to 2025-01-31
Land plants all share a common ancestor that made the leap from water to land. This major transition, known as terrestrialization, marked a pivotal moment in plant evolution. How exactly plants adapted to life on land is still a topic of active research, but it is clear that this process led to the development of new plant metabolic pathways. These pathways evolved in different plant species over time. Two important types of molecules that helped plants adapt to land are phenylpropanoids and apo-carotenoids derived molecules. Phenylpropanoids play a key role in protecting plants from harmful UV rays and serve as building blocks for plant cell structures. Apo-carotenoids, on the other hand, are involved in response to environmental stresses or plant interactions with the others species and their environment. Despite ongoing research, there is still much to learn about how these molecules were involved in plant adaptation to land. Interaction between proteins is one of the key processes allowing cells to specify and regulate their development and their response to the environmental constraints. The study of interactions between proteins is then essential in the understanding of many biological mechanisms. In plants, the role of protein-protein interactions in many biological mechanisms is yet not clear. Particularly, the extend and role of interaction between proteins in different plant lineages is unknown limiting our understanding of important biological events such as plant adaptation to land.
The EPPIMAL project searched to give insights into the role of interactions between proteins in the context of plant evolution and adaptation to land. Specifically, it aims to understand how proteins in the phenylpropanoid and apo-carotenoid derived pathways interact with other proteins in different plant species. The project focuses on three plants that are distantly related but represent major evolutionary branches: the flowering plant Arabidopsis thaliana, the liverwort Marchantia polymorpha, and the moss Physcomitrium patens. By studying these species, we hope to better understand the evolution of phenylpropanoid and apo-carotenoid derived metabolic pathways and their influence in the mechanisms contributing to plant adaptation to land. Specifically, in the apo-carotenoid derived pathways, the project focusses on the study of the abscisic acid (ABA) a key molecule involved in response to environmental stresses and plant development.
The EPPIMAL project searched to give insights into the role of interactions between proteins in the context of plant evolution and adaptation to land. Specifically, it aims to understand how proteins in the phenylpropanoid and apo-carotenoid derived pathways interact with other proteins in different plant species. The project focuses on three plants that are distantly related but represent major evolutionary branches: the flowering plant Arabidopsis thaliana, the liverwort Marchantia polymorpha, and the moss Physcomitrium patens. By studying these species, we hope to better understand the evolution of phenylpropanoid and apo-carotenoid derived metabolic pathways and their influence in the mechanisms contributing to plant adaptation to land. Specifically, in the apo-carotenoid derived pathways, the project focusses on the study of the abscisic acid (ABA) a key molecule involved in response to environmental stresses and plant development.
The EPPIMAL team is using a cutting-edge technique called proximity labeling, which allows scientists to track protein-protein interactions (PPIs) in living cells. This technique is combined with mass spectrometry, a method that helps detect and identify proteins. To do this, the researchers created special DNA constructs that allow the production of specific proteins, such as HYDROXYCINNAMOYL TRANSFERASE (HCT) from the phenylpropanoid pathway and ABSCISIC ACID 4 (ABA4) from the abscisic acid pathway, in fusion with the TurboID (TID) biotin ligase to tag other proteins in close proximity with biotin molecules. This allows us to study how HCT and ABA4 proteins interact with other proteins in the cell and in different plant species.
Tests in Arabidopsis thaliana showed that the fusion proteins (HCT-TID and ABA4-TID) perform similarly to the natural versions of these proteins. This means that these tagged proteins can be used in proximity labeling experiments to map out the networks of protein interactions. In the future, comparing the protein-protein interaction networks between the selected three plant species will help us to understand how these interactions evolved and how they might regulate phenylpropanoids and abscisic acid pathways.
In addition, since the role of ABA4 in non-vascular plants like liverworts and mosses was not well understood, the project also explored how this gene functions in the ABA pathway in Marchantia polymorpha and Physcomitrium patens. This research provides new insights into the role of ABA4 in these plants.
Tests in Arabidopsis thaliana showed that the fusion proteins (HCT-TID and ABA4-TID) perform similarly to the natural versions of these proteins. This means that these tagged proteins can be used in proximity labeling experiments to map out the networks of protein interactions. In the future, comparing the protein-protein interaction networks between the selected three plant species will help us to understand how these interactions evolved and how they might regulate phenylpropanoids and abscisic acid pathways.
In addition, since the role of ABA4 in non-vascular plants like liverworts and mosses was not well understood, the project also explored how this gene functions in the ABA pathway in Marchantia polymorpha and Physcomitrium patens. This research provides new insights into the role of ABA4 in these plants.
Studying protein-protein interactions in plant metabolic pathways has been challenging due to the dynamic nature of both protein interactions and metabolite production. Recent advancements in proximity labeling are helping to overcome these challenges, but there is still a lot we don't know, especially when it comes to plants from different evolutionary branches.
The findings from the EPPIMAL project will significantly improve our understanding of two key metabolic pathways — phenylpropanoids and abscisic acid — and their role in helping plants adapt to land environments. By uncovering new protein partners and regulators in these pathways, the project will also shed light on how plants evolved to thrive on land. Furthermore, comparing the protein-protein interaction networks of Arabidopsis (a flowering plant) with Marchantia(a liverwort) and Physcomitrium (a moss) will provide valuable insights into the evolutionary history of plants.
The findings from the EPPIMAL project will significantly improve our understanding of two key metabolic pathways — phenylpropanoids and abscisic acid — and their role in helping plants adapt to land environments. By uncovering new protein partners and regulators in these pathways, the project will also shed light on how plants evolved to thrive on land. Furthermore, comparing the protein-protein interaction networks of Arabidopsis (a flowering plant) with Marchantia(a liverwort) and Physcomitrium (a moss) will provide valuable insights into the evolutionary history of plants.