Mechanistic Systems modelling of plant environmental adaptation and CAM photosynthesis engineering

Introduction

A major goal of evolutionary biology is to reconstruct evolutionary trajectories and outcomes from mechanistic descriptions of the interactions between organisms and their environment. This goal is rarely reached due to the complexity of these interactions and their effects on fitness.

Advances in Technology

Recent advances in computer technology that facilitate the solution and optimization of large mathematical systems have now brought such models into reach.

Project Overview

In MECHSYS, I propose to develop a computational framework that builds on biochemical and physical principles to reconstruct how the interaction of the environment with plant anatomy, water transport, photosynthesis, and metabolism shapes plant physiology and fitness.

Mathematical Model

Mathematically, the model comprises:

1. Thermal balances
2. Balances of metabolites and water in different plant organs
3. Balances in the compartments of leaf cells

The model will use net CO2 fixation per root area over multiple days as a proxy for fitness. For a given climate and soil, the model will estimate fitness based on anatomical parameters and on systems-level protein concentrations and enzyme regulation.

Implications of Estimates

These estimates will allow us to rationalize the evolution and/or predominance of different types of plants in specific habitats.

Validation Process

We will validate the model against proteomics and metabolomics data from representatives of C3 plants and the much more water-use-efficient CAM plants, covering desert plants as well as epiphytes.

Simulation of Evolutionary Trajectories

Moreover, we will simulate evolutionary trajectories towards CAM photosynthesis and succulence, two traits whose evolution appears to be interlinked.

Application for Crop Engineering

Finally, we will utilize the model to propose optimal strategies for engineering crops to become more drought-resistant in increasingly hotter and drier climates.

Conclusion

Overall, MECHSYS will establish, test, and apply a ground-breaking, mechanistic systems modeling framework for evolutionary plant biology, which will allow deep insights into the selective forces that shape plant physiology and evolution.