AN INTEGRATED GENETIC AND BIOPHYSICAL APPROACH TO TOMATO CROP PROTECTION

Plant products are central to global food production and consumption, accounting for an annual U.S. market value of $5 billion for meat product replacements alone and corresponding to ~120 pounds of vegetables consumed per person in 2019. Fruits and vegetables also play important roles in sustainable energy efforts such as biomass conversion and biologically-inspired materials design for barrier applications such as food packaging. Despite gains in total factor agricultural productivity achieved for food crops in the United States in recent decades, staples such as fruits, vegetables, and grains face continuing challenges as they develop as well as during post-harvest storage and industrial processing; their production may also be threatened by climate change and other environmental stresses.Among major food commodities, for instance, both tomatoes and potatoes can suffer total crop loss due to infection by bacteria, fungi, and/or oomycetes - both during growth and at post-harvest stages. These terrestrial plants are also threatened abiotically by desiccation, radiative and thermal exposure, and mechanical forces. In this context and from a broader societal perspective, the National Research Council Committee on Twenty-First Century Systems Agriculture has called for research that satisfies human food needs and sustains the economic viability of agricultural practice. Both incremental and transformative strategies are recommended to improve a $4 trillion dollar global enterprise, with impact on stakeholders including farmers, processors, marketers, and a population of eight billion consumers worldwide.Our long-term research goals are to address these needs by seeking a foundational understanding of the molecular, thermodynamic, and biomechanical factors that underlie crop protection, which can offer essential guidance to enhance the agricultural yields and market readiness of fresh or processed foodstuffs. We have chosen the tomato fruit as our target organism and will focus our investigations on its outer cuticle, a protective epidermal structure that includes a specialized cell wall embedded with waxes and a cutin polyester. Four objectives will support our goals:(a) to produce tomato fruits for which respective gene knockouts will probe the control of transmembrane transport of monomeric hydroxyfatty acid cutin precursors and the polymerization required to construct their protective cuticles;(b) to understand how these genetic modifications compromise cuticle-dependent resistance to water and heat losses via changes in thermodynamic properties;(c) to test for consequent changes in the surface stiffness and overall mechanical strength of the fruit cuticles;(d) to uncover the changes in molecular structure and macromolecular architecture associated with these genetically encoded disruptions of tomato fruit cutin biopolymer development.To these ends, the PI has assembled a three-investigator team (Ruth Stark, City University of New York, City College campus (CUNY CCNY) (PI)); Christiane Nawrath, U. of Lausanne, Switzerland; Jocelyn Rose, Cornell U.) with strong track records in plant cuticle research and complementary expertise in plant molecular biology, enzymology, and molecular biophysics.