RNA interference for sustainable plant protection

Abstract

RNA interference (RNAi)-based plant protection is an environmentally sustainable disease control strategy effective against plant viruses, insect pests and fungal pathogens. It relies on the highly conserved eukaryotic cellular defence mechanism RNAi, whereby double stranded RNA (dsRNA) triggers the silencing of homologous nucleic acid. Initial RNAi-based plant protection approaches relied on the genetic modification (GM) of host plants, however non-GM approaches such as exogenous RNAi, which involve topically applying pest/pathogen-specific dsRNA to plants, are also now available. We have been exploring exogenous RNAi as a novel control for Phytophthora root rot and myrtle rust, two aggressive diseases which are destroying natural plant populations across Australia and causing significant economic losses to horticulture, forestry and native plant industries. We have synthesised dsRNA molecules which have fungicidal effects against Phytophthora cinnamomi (causal agent of Phytophthora root rot) and Austropuccinia psidii (myrtle rust) in vitro and in planta and are now investigating the longevity and mechanism of RNAi-induced protection. Our ultimate goal is to develop a clean green safe control strategy for these invasive diseases to safeguard Australian horticulture, forestry and native plant industries, with long-term benefits for conservation and biodiversity. 

Biography

Dr Anne Sawyer is an Advance Queensland Industry Research Fellow developing RNA interference (RNAi)-based protection technologies against destructive plant pathogens. Anne completed her PhD at the Institute for Molecular Biosciences on the regulation of photosynthetic gene expression followed by a postdoc at Ruhr-University Bochum, Germany on microalgal hydrogen production. She returned to Australia and UQ in 2018 to work with Prof Bernie Carroll and Prof Neena Mitter on RNAi in plants and plant pathogenic fungi. Anne works closely with partners at the Department of Agriculture and Fisheries, Scion New Zealand, Nufarm Australia, Greenlife Industry Australia, Australian Pineapples, Howe Farming Enterprises, Australian Native Products and the Australian Tea Tree Industry Association to translate her research into a technology that can be used by Australian growers as an environmentally friendly alternative to broad-spectrum fungicides.