Terrestrial plants regulate their interactions with the environment via insoluble hydrophobic molecules assembled within epidermal or peridermal cell walls: cutins, suberins, and waxes that share some building blocks and formation pathways. To understand the macromolecular structure and mechanical performance of these essential protective membranes, gene-silenced tomato fruits and potato tubers as well as leaves from several model plants will be targeted for study. A coordinated protocol of biophysical measurements will link the biosynthesis of plant coverings with their molecular architectures and macroscopic attributes such as mechanical integrity and environmental persistence. The project can benefit food crop yields and recycling of plant litter, also aiding the design of paints, textiles, and coatings. Interdisciplinary training teams spanning high school through postdoctoral levels will conduct this research, which will also form the basis of an undergraduate laboratory curriculum for non-scientists.
The long-term objective of this program is to transform the current phenomenology of protective plant cuticles and periderms into a comprehensive predictive scheme for the versatile barrier functions of hydrophobic membranes. In addition to benefits related to food crop protection and plant litter recycling, the project outcomes can inform the design of superhydrophobic paints, textiles, and coatings. Recent improvements in genetic, analytical, and biomechanical technologies are making it possible to achieve an understanding of plant cuticular architecture that spans length scales from molecular to macroscopic, development from biosynthesis to biodegradation, and mechanical integrity at the surface or in bulk. This project will examine the biosynthesis, macromolecular organization, and mechanical performance of cuticles and periderms from tomato (Solanum lycopersicum) and potato (Solanum tuberosum) plants with known genomes. As a complement, the polymers that resist chemical degradation and modulate plant cuticular function will be identified structurally. Specific hypotheses will be tested to address several issues: specificity of two fruit cutin synthase enzymes; metabolic rerouting of gene-silenced potato tuber periderms; macromolecular organization of suberized potato cell walls; nanomechanics and tensile strength of cuticles and periderms, respectively; environmental persistence of cutins and suberins.
