P-044 - Functional Characterization of Tomato ERFs in Botrytis cinerea Resistance

Ethylene response factors (ERFs) regulate plant immunity, particularly responses to necrotrophic pathogens. ORA59, an ERF in Arabidopsis thaliana, integrates jasmonic acid (JA) and ethylene (ET) signaling, which function synergistically in defense while also acting independently. However, ORA59 homologs in tomato remain largely unexplored. Here, we analyzed tomato ORA59 homologs to identify ERFs involved in resistance to Botrytis cinerea. Based on their expression patterns in response to B. cinerea and hormone treatments, two genes, SlERF.F and SlERF.H, were selected as putative regulators of disease resistance. Both VIGS-mediated silencing and CRISPR-Cas9-mediated mutants of SlERF.F and SlERF.H showed reduced resistance to B. cinerea. Conversely, overexpression of either gene enhanced resistance, suggesting a positive regulatory function. To further explore their molecular functions, transgenic tomato lines overexpressing SlERF.F and SlERF.H are under development. These results indicate that SlERF.F and SlERF.H are key components of the defense response against necrotrophic pathogens and contribute to understanding ERF-mediated immunity in tomato. This study provides new insights into ERF function in plant defense, offering potential strategies for engineering disease-resistant crops through targeted gene regulation.