title: Silicon does not mitigate cell death in cultured tobacco BY-2 cells subjected to salinity without ethylene emission.
abstract: Silicon induces cell death when ethylene is suppressed in cultured tobacco BY-2 cells. There is a crosstalk between Si and ethylene signaling. Silicon (Si) is beneficial for plant growth. It alleviates both biotic and abiotic stresses in plants. How Si works in plants is still mysterious. This study investigates the mechanism of Si-induced cell death in tobacco BY-2 cell cultures when ethylene is suppressed. Results showed that K2SiO3 alleviated the damage of NaCl stress. Si treatment rapidly increased ethylene emission and the expression of ethylene biosynthesis genes. Treatments with Si + Ag and Si + aminooxyacetic acid (AOA, ethylene biosynthesis inhibitor) reduced the cell growth and increased cell damage. The treatment with Si + Ag induced hydrogen peroxide (H2O2) generation and ultimately cell death. Some nucleus of BY-2 cells treated with Si + Ag appeared TUNEL positive. The inhibition of H2O2 and nitric oxide (NO) production reduced the cell death rate induced by Si + Ag treatment. Si eliminated the up-regulation of alternative pathway by Ag. These data suggest that ethylene plays an important role in Si function in plants. Without ethylene, Si not only failed to enhance plant resistance, but also elevated H2O2 generation and further induced cell death in tobacco BY-2 cells.
authors.affiliation: Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, People's Republic of China.
authors.forename: Xiaolei
authors.initials: X
authors.lastname: Liang
authors.forename: Huahua
authors.initials: H
authors.lastname: Wang
authors.forename: Yanfeng
authors.initials: Y
authors.lastname: Hu
authors.forename: Lina
authors.initials: L
authors.lastname: Mao
authors.forename: Lili
authors.initials: L
authors.lastname: Sun
authors.forename: Tian
authors.initials: T
authors.lastname: Dong
authors.forename: Wenbin
authors.initials: W
authors.lastname: Nan
authors.forename: Yurong
authors.initials: Y
authors.lastname: Bi
mesh_terms: D000625:Aminooxyacetic Acid / Q000494:pharmacology; D016923:Cell Death / Q000187:drug effects; D002478:Cells, Cultured; D005030:Ethylenes / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000187:drug effects*; D006861:Hydrogen Peroxide / Q000378:metabolism; D015227:Lipid Peroxidation; D009569:Nitric Oxide / Q000378:metabolism; D010937:Plant Growth Regulators / Q000378:metabolism; D054712:Salinity; D055049:Salt Tolerance; D015398:Signal Transduction; D012825:Silicon / Q000494:pharmacology*; D012834:Silver / Q000494:pharmacology; D012965:Sodium Chloride / Q000494:pharmacology*; D014026:Nicotiana / Q000187:drug effects* / Q000235:genetics / Q000502:physiology; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D005030:Ethylenes; D010937:Plant Growth Regulators; D000625:Aminooxyacetic Acid; D009569:Nitric Oxide; D012834:Silver; D012965:Sodium Chloride; C036216:ethylene; D006861:Hydrogen Peroxide; D012825:Silicon