Collaborative Research: Development of an in Silico Full Leaf Model Validated by Experiments

Designing and building mechanically robust, multi-functional materials is a challenging problem in engineering. However, naturally occurring biological materials typically perform multiple functions and are robust to environmental disturbances throughout their development. In contrast to most human-engineered materials, biological materials are often formed through self-assembly, a process that occurs when large-scale emergent structures form not from overarching designs, but instead from physical interactions between cells and other structures. One of the most important organs in nature is the plant leaf, which is the site of almost all terrestrial carbon fixation globally. Despite being seemingly planar, leaves are three-dimensional organs composed of multiple, porous tissues that develop from tightly compacted, undifferentiated cells. This award supports research to create a three-dimensional model of leaf development to recapitulate the structural diversity among real leaves and test how this structural variation influences leaf performance. In so doing, this project will create a "virtual leaf" platform for future studies of leaf function and advance the development of self-assembling, biomimetic materials, as well as mentoring and educating high school, undergraduate, and graduate students. Building stable, porous materials with tunable and targeted properties through self-assembly has the potential to transform material science and engineering. This project uses the plant leaf as a model of self-assembly because it is composed of multiple tissues organized in three dimensions (3D) that vary in properties ranging from completely confluent to highly porous, even though each of these tissues develop in unison from undifferentiated, identical cells. This research will (1) develop new image analysis methods to characterize the 3D cell and tissue structural diversity of leaves to guide modeling, (2) develop a 3D computational model of leaf development incorporating all major leaf tissues, and (3) test how structural variation at the cell and tissue levels influence the mechanical and functional properties of leaves. Together these aims will illuminate approaches for engineering multifunctional materials with tunable properties and structural heterogeneity. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.