title: Silencing in sperm cells is directed by RNA movement from the surrounding nurse cell.
abstract: Plant small interfering RNAs (siRNAs) communicate from cell to cell and travel long distances through the vasculature. However, siRNA movement into germ cells has remained controversial, and has gained interest because the terminally differentiated pollen vegetative nurse cell surrounding the sperm cells undergoes a programmed heterochromatin decondensation and transcriptional reactivation of transposable elements (TEs). Transcription of TEs leads to their post-transcriptional degradation into siRNAs, and it has been proposed that the purpose of this TE reactivation is to generate and load TE siRNAs into the sperm cells. Here, we identify the molecular pathway of TE siRNA production in the pollen grain and demonstrate that siRNAs produced from pollen vegetative cell transcripts can silence TE reporters in the sperm cells. Our data demonstrates that TE siRNAs act non-cell-autonomously, inhibiting TE activity in the germ cells and potentially the next generation.
authors.affiliation: Department of Molecular Genetics and Center for RNA Biology, The Ohio State University, 500 Aronoff Laboratory, 318 West 12th Avenue, Columbus, Ohio 43210, USA.
authors.forename: Germán
authors.initials: G
authors.lastname: Martínez
authors.affiliation: Department of Molecular Genetics and Center for RNA Biology, The Ohio State University, 500 Aronoff Laboratory, 318 West 12th Avenue, Columbus, Ohio 43210, USA.
authors.forename: Kaushik
authors.initials: K
authors.lastname: Panda
authors.affiliation: Department of Plant Biology, Swedish University of Agricultural Sciences and Linnean Center of Plant Biology, SE-750 07 Uppsala, Sweden.
authors.forename: Claudia
authors.identifier: 0000-0002-2619-4857
authors.initials: C
authors.lastname: Köhler
authors.affiliation: Department of Molecular Genetics and Center for RNA Biology, The Ohio State University, 500 Aronoff Laboratory, 318 West 12th Avenue, Columbus, Ohio 43210, USA.
authors.forename: R Keith
authors.initials: RK
authors.lastname: Slotkin
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000502:physiology*; D004251:DNA Transposable Elements / Q000235:genetics*; D056130:Gametogenesis, Plant / Q000502:physiology*; D011058:Pollen / Q000235:genetics*; D034622:RNA Interference / Q000502:physiology*; D018749:RNA, Plant / Q000235:genetics* / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics* / Q000378:metabolism
chemical_list: D004251:DNA Transposable Elements; D018749:RNA, Plant; D034741:RNA, Small Interfering