Struktur, Biosynthese und ökologische Rolle von spezialisierten Lipiden in Tomaten
Organismische Interaktionen, chemische Ökologie und Mikrobiome pflanzlicher Systeme
Zusammenfassung der Projektergebnisse
The cuticle is the outer layer of plants providing a protective shielding against attacking organisms like agriculturally relevant fungal pathogens. New approaches to reduce the burden of fungal pathogens are needed to replace the use of externally applied fungicides. One of these approaches involves leveraging 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. Relative to the constitutive cuticle pathway, the identity and function of these specialized lipids, induced by pathogen stress, are less well understood. In our lab, we found a set of specialized biosynthesis genes for the inducible production of an unusual lipid in tomato (falcarindiol). We unexpectedly discovered that genetic knockouts improve the 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 leveraged our discovery of a highly responsive set of specialized metabolic genes to elucidate the complete set of metabolites that respond to fungal infection, including aminecontaining lipids that have not been described in plants before. In parallel, we tracked the site of accumulation of these lipids in planta as a critical step towards understanding their role in the tomato-fungal interactions. Lastly, we identified additional enzymes that co-function with the recently discovered tomato acetylenase, and dedicated transcription factors that regulate the production of these unique lipids.
