P-388 - Exploring the Use of RNA Interference for the Management of Coffee Leaf Rust and Ceratocystis Diseases

Coffee leaf rust (CLR), caused by Hemileia vastatrix, and Rapid Ohia Death (ROD), caused by Ceratocystis spp., are major threats to plant health, leading to significant economic and ecological losses. CLR reduces coffee yields globally, while ROD is rapidly decimating native Ohia forests in Hawaii. Current management strategies, including fungicides, resistant cultivars, and quarantine efforts, have limitations due to pathogen adaptation, environmental concerns, and lack of effective long-term solutions. This highlights the urgent need for novel, sustainable disease control methods. RNA interference (RNAi) is an emerging biotechnology that enables targeted gene silencing in fungal pathogens. By interfering with essential fungal gene expression, RNAi has the potential to suppress pathogen growth and infection. However, its effectiveness against H. vastatrix and Ceratocystis spp. remains largely unexplored. This study investigates RNAi-based control by targeting genes involved in fundamental cellular functions, including cell structure, respiration, and energy production, such as β-tubulin (TUB), chitin synthases (CHS), and cytochrome c oxidase (COX). We evaluate RNAi efficiency through in vitro assays, gene knockdown assessment, pathogen growth reduction, and disease symptom development. Understanding RNAi efficacy in these systems will provide valuable insights into its potential as a sustainable alternative management strategy for these two important fungal plant diseases.