title: Clay nanosheets for topical delivery of RNAi for sustained protection against plant viruses.
abstract: Topical application of pathogen-specific double-stranded RNA (dsRNA) for virus resistance in plants represents an attractive alternative to transgenic RNA interference (RNAi). However, the instability of naked dsRNA sprayed on plants has been a major challenge towards its practical application. We demonstrate that dsRNA can be loaded on designer, non-toxic, degradable, layered double hydroxide (LDH) clay nanosheets. Once loaded on LDH, the dsRNA does not wash off, shows sustained release and can be detected on sprayed leaves even 30 days after application. We provide evidence for the degradation of LDH, dsRNA uptake in plant cells and silencing of homologous RNA on topical application. Significantly, a single spray of dsRNA loaded on LDH (BioClay) afforded virus protection for at least 20 days when challenged on sprayed and newly emerged unsprayed leaves. This innovation translates nanotechnology developed for delivery of RNAi for human therapeutics to use in crop protection as an environmentally sustainable and easy to adopt topical spray.
authors.affiliation: Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia.
authors.forename: Neena
authors.initials: N
authors.lastname: Mitter
authors.affiliation: Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Worrall
authors.affiliation: Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia.
authors.forename: Karl E
authors.initials: KE
authors.lastname: Robinson
authors.affiliation: Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia.
authors.forename: Peng
authors.identifier: 0000-0002-3939-1585
authors.initials: P
authors.lastname: Li
authors.affiliation: Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia.
authors.forename: Ritesh G
authors.initials: RG
authors.lastname: Jain
authors.affiliation: Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia.|School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia.
authors.forename: Christelle
authors.initials: C
authors.lastname: Taochy
authors.affiliation: Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia.|School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Fletcher
authors.affiliation: School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia.
authors.forename: Bernard J
authors.initials: BJ
authors.lastname: Carroll
authors.affiliation: Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia.|University of Surrey, Guildford GU2 7XH, UK.
authors.forename: G Q Max
authors.initials: GQ
authors.lastname: Lu
authors.affiliation: Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia.
authors.forename: Zhi Ping
authors.identifier: 0000-0001-6070-5035
authors.initials: ZP
authors.lastname: Xu
mesh_terms: D000538:Aluminum Silicates / Q000494:pharmacology*; D017360:Arabidopsis / Q000502:physiology; D000077215:Clay; D049329:Nanostructures / Q000737:chemistry*; D010935:Plant Diseases / Q000517:prevention & control* / Q000821:virology; D010942:Plant Viruses / Q000187:drug effects* / Q000235:genetics; D034622:RNA Interference; D012330:RNA, Double-Stranded / Q000494:pharmacology*; D012367:RNA, Viral / Q000494:pharmacology*; D014026:Nicotiana / Q000502:physiology; D000070658:Vigna / Q000502:physiology
chemical_list: D000538:Aluminum Silicates; D012330:RNA, Double-Stranded; D012367:RNA, Viral; D000077215:Clay