title: A small RNA targets pokeweed antiviral protein transcript.
abstract: Ribosome-inactivating proteins (RIPs) are a class of plant defense proteins with N-glycosidase activity (EC 3.2.2.22). Pokeweed antiviral protein (PAP) is a Type I RIP isolated from the pokeweed plant, Phytolacca americana, thought to confer broad-spectrum virus resistance in this plant. Through a combination of standard molecular techniques and RNA sequencing analysis, we report here that a small RNA binds and cleaves the open reading frame of PAP mRNA. Additionally, sRNA targeting of PAP is dependent on jasmonic acid (JA), a plant hormone important for defense against pathogen infection and herbivory. Levels of small RNA increased with JA treatment, as did levels of PAP mRNA and protein, suggesting that the small RNA functions to moderate the expression of PAP in response to this hormone. The association between JA and PAP expression, mediated by sRNA299, situates PAP within a signaling pathway initiated by biotic stress. The consensus sequence of sRNA299 was obtained through bioinformatic analysis of pokeweed small RNA sequencing. To our knowledge, this is the first account of a sRNA targeting a RIP gene.
authors.affiliation: Department of Biology, York University, Toronto, Ontario, Canada.
authors.forename: Alexander
authors.initials: A
authors.lastname: Klenov
authors.affiliation: Department of Biology, York University, Toronto, Ontario, Canada.
authors.forename: Kira C M
authors.initials: KC
authors.lastname: Neller
authors.affiliation: Department of Biology, York University, Toronto, Ontario, Canada.
authors.forename: Lydia A
authors.initials: LA
authors.lastname: Burns
authors.affiliation: Department of Biology, York University, Toronto, Ontario, Canada.
authors.forename: Gabriela
authors.initials: G
authors.lastname: Krivdova
authors.affiliation: Department of Biology, York University, Toronto, Ontario, Canada.
authors.forename: Katalin A
authors.initials: KA
authors.lastname: Hudak
mesh_terms: D001483:Base Sequence; D003517:Cyclopentanes / Q000494:pharmacology; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D008969:Molecular Sequence Data; D009711:Nucleotides / Q000235:genetics; D054883:Oxylipins / Q000494:pharmacology; D029604:Phytolacca americana / Q000187:drug effects / Q000235:genetics; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018749:RNA, Plant / Q000378:metabolism*; D015203:Reproducibility of Results; D054789:Ribosome Inactivating Proteins, Type 1 / Q000235:genetics / Q000378:metabolism*; D017423:Sequence Analysis, RNA; D024363:Transcription Initiation Site
chemical_list: D003517:Cyclopentanes; D009711:Nucleotides; D054883:Oxylipins; D010940:Plant Proteins; D012333:RNA, Messenger; D018749:RNA, Plant; D054789:Ribosome Inactivating Proteins, Type 1; C011006:jasmonic acid; C024275:pokeweed antiviral protein