Structure, Biosynthesis, and Ecological Role of Specialized Lipids in Tomato

• Applicant: Dr. Sarah Niehs
• Subject Area: Biological and Biomimetic Chemistry ; Organismic Interactions, Chemical Ecology and Microbiomes of Plant Systems
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 516932270

The cuticle, the outer layer of plants, provides a protective barrier for plant-pathogen interactions, including agriculturally relevant pathogen. New approaches to reducing the burden of fungal pathogens are needed to replace the use of externally applied fungicide and will leverage the ability of different plant species to resist infection. Many cuticle biosynthetic genes have been shown to alter plant susceptibility to pathogens. Cuticle composition appears to be dynamic and responds to pathogen stress with the production of specialized lipids. In comparison to the constitutive cuticle pathway, the identity and function of these specialized lipids, induced on pathogen stress, are less well understood. In our lab, we recently found a set of specialized biosynthesis genes responsible for the inducible production of an unusual lipid in tomato (falcarindiol). Unexpectedly we demonstrated that deficient mutants were improved in plant defense against a necrotrophic pathogen . Preliminary data indicates that multiple molecules, in addition to the metabolite falcarindiol, derive from these genes. The identity of these compounds is not known, and their role in the unexpected protection phenotype of mutants has not been found. Here we will leverage our discovery of a highly responsive set of specialized metabolic genes to elucidate the complete complex of metabolites that respond to fungal infection, including putative amine-containing lipids that have not been described in plants before. In parallel, we will identify additional enzymes that co-function with the recently discovered tomato acetylenase, and dedicated transcription factors that regulate the production of these unique lipids. Lastly, we will track the site of accumulation of these lipids in planta as a critical step towards understanding their role in the tomato-fungal interactions. The long-term goal of this project is to enable the bioengineering of lipid production in plants to decrease susceptibility to fungal pathogens as an alternative to fungicide application, as a more sustainable approach to alleviating crop loss, and enhancing food shelf-life.

• DFG Programme: WBP Fellowship
• International Connection: USA
• Host: Privatdozentin Dr. Elizabeth Sattely, Ph.D.