RT Conference Proceedings T1 Conserved and non-annotated proteins of Podosphaera xanthii: new target candidates for the control of powdery mildews by spray-induced gene silencing. A1 Ruiz-Jimenez, Laura A1 Polonio Escalona, Alvaro Acisclo A1 Vielba-Fernández, Alejandra A1 Pérez-García, Alejandro A1 Fernández-Ortuño, Dolores K1 Hongos fitopatógenos K1 Plantas - Resistencia a enfermedades y plagas K1 Proteínas AB One of the most important limiting factors for cucurbit production worldwide is the powdery mildew fungus Podosphaera xanthii. Despite the efforts invested in plant breeding programs and chemical companies, effective control of this pathogen remains elusive to growers. In this work, we examined the potential of RNAi technology called spray-induced gene silencing (SIGS) for controlling cucurbit powdery mildew. For that, we first developed a new and simple gene silencing method for P. xanthii based on the application of dsRNAs to the plant surface. Moreover, to identify new target candidate genes, we focused on the study of a set of sixty conserved and non-annotated proteins (CNAPs) deduced from the P. xanthii transcriptome. After protein modeling and ligand prediction studies, six proteins presumably involved in respiration, glycosylation and efflux transport, were selected. Functional analysis of these CNAP coding genes by dsRNA-induced gene silencing resulted in strong silencing phenotypes with large reductions in fungal growth and disease symptoms. Due to their important contributions to fungal development, three of these CNAP genes were selected as targets to conduct SIGS assays under plant growth chamber conditions. The spray application of these dsRNAs induced high levels of disease control, supporting that SIGS could be a promising tool for controlling powdery mildews. This work has been funded by AEI (AGL2016-76216-C2-1-R; PID2019-107464RB-C21). YR 2023 FD 2023 LK https://hdl.handle.net/10630/27452 UL https://hdl.handle.net/10630/27452 LA eng NO Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. DS RIUMA. Repositorio Institucional de la Universidad de Málaga RD 20 ene 2026