title: Sulfated lentinan induced mitochondrial dysfunction leads to programmed cell death of tobacco BY-2 cells.
abstract: Sulphated lentinan (sLTN) is known to act as a resistance inducer by causing programmed cell death (PCD) in tobacco suspension cells. However, the underlying mechanism of this effect is largely unknown. Using tobacco BY-2 cell model, morphological and biochemical studies revealed that mitochondrial reactive oxygen species (ROS) production and mitochondrial dysfunction contribute to sLNT induced PCD. Cell viability, and HO/PI fluorescence imaging and TUNEL assays confirmed a typical cell death process caused by sLNT. Acetylsalicylic acid (an ROS scavenger), diphenylene iodonium (an inhibitor of NADPH oxidases) and protonophore carbonyl cyanide p-trifluoromethoxyphenyl hydrazone (a protonophore and an uncoupler of mitochondrial oxidative phosphorylation) inhibited sLNT-induced H2O2generation and cell death, suggesting that ROS generation linked, at least partly, to a mitochondrial dysfunction and caspase-like activation. This conclusion was further confirmed by double-stained cells with the mitochondria-specific marker MitoTracker RedCMXRos and the ROS probe H2DCFDA. Moreover, the sLNT-induced PCD of BY-2 cells required cellular metabolism as up-regulation of the AOX family gene transcripts and induction of the SA biosynthesis, the TCA cycle, and miETC related genes were observed. It is concluded that mitochondria play an essential role in the signaling pathway of sLNT-induced ROS generation, which possibly provided new insight into the sLNT-mediated antiviral response, including PCD.
authors.affiliation: Tobacco Research Institute, Chinese Academy of Agricultural Sciences, 11 Keyuanjing Si Rd., Laoshan District, Qingdao, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Wang
authors.affiliation: Qingyang Oriental Tobacco Company Ltd., Gansu, China.
authors.forename: Yaofeng
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Tobacco Research Institute, Chinese Academy of Agricultural Sciences, 11 Keyuanjing Si Rd., Laoshan District, Qingdao, China.
authors.forename: Lili
authors.initials: L
authors.lastname: Shen
authors.affiliation: Tobacco Research Institute, Chinese Academy of Agricultural Sciences, 11 Keyuanjing Si Rd., Laoshan District, Qingdao, China.
authors.forename: Yumei
authors.initials: Y
authors.lastname: Qian
authors.affiliation: Tobacco Research Institute, Chinese Academy of Agricultural Sciences, 11 Keyuanjing Si Rd., Laoshan District, Qingdao, China. Electronic address: yangjinguang@caas.cn.
authors.forename: Jinguang
authors.initials: J
authors.lastname: Yang
authors.affiliation: Tobacco Research Institute, Chinese Academy of Agricultural Sciences, 11 Keyuanjing Si Rd., Laoshan District, Qingdao, China. Electronic address: wangfenglong@caas.cn.
authors.forename: Fenglong
authors.initials: F
authors.lastname: Wang
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3 / Q000378:metabolism; D053453:Caspase 9 / Q000378:metabolism; D002460:Cell Line; D045304:Cytochromes c / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects; D007655:Ketoglutarate Dehydrogenase Complex / Q000235:genetics; D007912:Lentinan / Q000031:analogs & derivatives* / Q000633:toxicity; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D033681:Mitochondrial Membrane Transport Proteins / Q000378:metabolism; D000083162:Mitochondrial Permeability Transition Pore; D017382:Reactive Oxygen Species / Q000378:metabolism; D014026:Nicotiana / Q000166:cytology / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism
chemical_list: D033681:Mitochondrial Membrane Transport Proteins; D000083162:Mitochondrial Permeability Transition Pore; D017382:Reactive Oxygen Species; C059822:lentinan sulfate; D007912:Lentinan; D045304:Cytochromes c; D007655:Ketoglutarate Dehydrogenase Complex; D053148:Caspase 3; D053453:Caspase 9
keywords: Caspase-like protease; Mitochondria; Programmed cell death; Reactive oxygen species; Respiratory chain; Sulfated lentinan