title: Functionalized mesoporous silica nanoparticles with redox-responsive short-chain gatekeepers for agrochemical delivery.
abstract: The controlled release of salicylic acid (SA), a key phytohormone, was mediated by using a novel decanethiol gatekeeper system grafted onto mesoporous silica nanoparticles (MSNs). The decanethiol was conjugated only to the external surfaces of the MSNs through glutathione (GSH)-cleavable disulfide linkages and the introduction of a process to assemble gatekeepers only on the outer surface so that the mesopore area can be maintained for high cargo loading. Raman and nitrogen sorption isotherm analyses confirmed the successful linkage of decanethiol to the surface of MSNs. The in vitro release of SA from decanethiol gated MSNs indicated that the release rate of SA in an environment with a certain amount of GSH was significantly higher than that without GSH. More importantly, in planta experiments showed the release of SA from decanethiol gated MSNs by GSH induced sustained expression of the plant defense gene PR-1 up to 7 days after introduction, while free SA caused an early peak in PR-1 expression which steadily decreased after 3 days. This study demonstrates the redox-responsive release of a phytohormone in vitro and also indicates the potential use of MSNs in planta as a controlled agrochemical delivery system.
authors.affiliation: †Institute for Frontier Materials, Deakin University, Geelong Campus at Waurn Ponds, Geelong, Victoria 3216, Australia.
authors.forename: Zhifeng
authors.initials: Z
authors.lastname: Yi
authors.affiliation: ‡Center for Chemistry and Biotechnology, School of Life and Environmental Sciences, Deakin University, Geelong Campus at Waurn Ponds, Geelong, Victoria 3216, Australia.
authors.forename: Hashmath I
authors.initials: HI
authors.lastname: Hussain
authors.affiliation: †Institute for Frontier Materials, Deakin University, Geelong Campus at Waurn Ponds, Geelong, Victoria 3216, Australia.
authors.forename: Chunfang
authors.initials: C
authors.lastname: Feng
authors.affiliation: ‡Center for Chemistry and Biotechnology, School of Life and Environmental Sciences, Deakin University, Geelong Campus at Waurn Ponds, Geelong, Victoria 3216, Australia.
authors.forename: Dequan
authors.initials: D
authors.lastname: Sun
authors.affiliation: †Institute for Frontier Materials, Deakin University, Geelong Campus at Waurn Ponds, Geelong, Victoria 3216, Australia.
authors.forename: Fenghua
authors.initials: F
authors.lastname: She
authors.affiliation: ‡Center for Chemistry and Biotechnology, School of Life and Environmental Sciences, Deakin University, Geelong Campus at Waurn Ponds, Geelong, Victoria 3216, Australia.
authors.forename: James E
authors.initials: JE
authors.lastname: Rookes
authors.affiliation: ‡Center for Chemistry and Biotechnology, School of Life and Environmental Sciences, Deakin University, Geelong Campus at Waurn Ponds, Geelong, Victoria 3216, Australia.
authors.forename: David M
authors.initials: DM
authors.lastname: Cahill
authors.affiliation: †Institute for Frontier Materials, Deakin University, Geelong Campus at Waurn Ponds, Geelong, Victoria 3216, Australia.
authors.forename: Lingxue
authors.initials: L
authors.lastname: Kong
mesh_terms: D016573:Agrochemicals / Q000737:chemistry*; D017360:Arabidopsis / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D020043:Genes, Essential; D005978:Glutathione; D053758:Nanoparticles / Q000737:chemistry*; D017646:Organosilicon Compounds; D010084:Oxidation-Reduction; D016062:Porosity; D020156:Salicylic Acid / Q000032:analysis; D012821:Silanes / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry*; D013059:Spectrum Analysis, Raman; D013499:Surface Properties
chemical_list: D016573:Agrochemicals; D017646:Organosilicon Compounds; D012821:Silanes; D012822:Silicon Dioxide; C102833:(3-mercaptopropyl)trimethoxysilane; D005978:Glutathione; D020156:Salicylic Acid
keywords: agrochemical delivery system; decanethiol gatekeepers; mesoporous silica nanoparticles (MSNs); redox-responsive gatekeepers; stimuli-response