title: Time course of programmed cell death, which included autophagic features, in hybrid tobacco cells expressing hybrid lethality.
abstract: PCD with features of vacuolar cell death including autophagy-related features were detected in hybrid tobacco cells, and detailed time course of features of vacuolar cell death were established. A type of interspecific Nicotiana hybrid, Nicotiana suaveolens × N. tabacum exhibits temperature-sensitive lethality. This lethality results from programmed cell death (PCD) in hybrid seedlings, but this PCD occurs only in seedlings and suspension-cultured cells grown at 28 °C, not those grown at 36 °C. Plant PCD can be classified as vacuolar cell death or necrotic cell death. Induction of autophagy, vacuolar membrane collapse and actin disorganization are each known features of vacuolar cell death, but observed cases of PCD showing all these features simultaneously are rare. In this study, these features of vacuolar cell death were evident in hybrid tobacco cells expressing hybrid lethality. Ion leakage, plasma membrane disruption, increased activity of vacuolar processing enzyme, vacuolar membrane collapse, and formation of punctate F-actin foci were each evident in these cells. Transmission electron microscopy revealed that macroautophagic structures formed and tonoplasts ruptured in these cells. The number of cells that contained monodansylcadaverine (MDC)-stained structures and the abundance of nine autophagy-related gene transcripts increased just before cell death at 28 °C; these features were not evident at 36 °C. We assessed whether an autophagic inhibitor, wortmannin (WM), influenced lethality in hybrid cells. After the hybrid cell began to die, WM suppressed increases in ion leakage and cell deaths, and it decreased the number of cells containing MDC-stained structures. These results showed that several features indicative of autophagy and vacuolar cell death were evident in the hybrid tobacco cells subject to lethality. In addition, we documented a detailed time course of these vacuolar cell death features.
authors: United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Tokyo, Japan.
authors: Naoya
authors: N
authors: Ueno
authors: Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, Japan.
authors: Saori
authors: S
authors: Nihei
authors: Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, Japan.
authors: Naoto
authors: N
authors: Miyakawa
authors: United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Tokyo, Japan.|Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, Japan.|Global Innovation Research Organization, Tokyo University of Agriculture and Technology, Tokyo, Japan.
authors: Tadashi
authors: T
authors: Hirasawa
authors: United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Tokyo, Japan.|Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, Japan.
authors: Motoki
authors: M
authors: Kanekatsu
authors: Faculty of Agricultural Science, Meiji University, Kanagawa, Japan.
authors: Wataru
authors: W
authors: Marubashi
authors: Mann Laboratory, Department of Plant Sciences, University of California, Davis, CA, USA.|Global Innovation Research Organization, Tokyo University of Agriculture and Technology, Tokyo, Japan.
authors: Wouter G
authors: WG
authors: van Doorn
authors: United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Tokyo, Japan. teyamada@cc.tuat.ac.jp.|Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, Japan. teyamada@cc.tuat.ac.jp.|Global Innovation Research Organization, Tokyo University of Agriculture and Technology, Tokyo, Japan. teyamada@cc.tuat.ac.jp.
authors: Tetsuya
authors: T
authors: Yamada
mesh_terms: D000199:Actins / Q000378:metabolism; D017209:Apoptosis; D001343:Autophagy; D002452:Cell Count; D003433:Crosses, Genetic; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D006824:Hybridization, Genetic; D059828:Plant Cells / Q000378:metabolism* / Q000648:ultrastructure; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013696:Temperature; D013997:Time Factors; D014026:Nicotiana / Q000166:cytology* / Q000235:genetics*; D014617:Vacuoles / Q000378:metabolism / Q000648:ultrastructure
chemical_list: D000199:Actins; D010940:Plant Proteins; D012333:RNA, Messenger
keywords: Autophagy; Hybrid lethality; Programmed cell death; Tobacco; Vacuolar cell death