title: Sulfur dioxide induced programmed cell death in Vicia guard cells.
abstract: Sulfur dioxide (SO(2)) induced nuclear condensation and nuclear fragmentation and rapid loss of guard cell viability in detached epidermis of Vicia leaves at concentrations of 1 mM and higher (3 h exposure). Caspase inhibitors Z-Asp-CH(2)-DCB (0.1 mM) and TLCK (0.1 mM) markedly suppressed SO(2)-induced cell death. The typical nuclear morphological changes and the inhibition effects of caspase inhibitors suggest the activation of a programmed cell death (PCD) pathway. SO(2)-induced cell death can be blocked by either antioxidants (0.1 mM AsA or 200 U/mL CAT) or Ca(2+) antagonists (0.1mM EGTA or LaCl(3)). AsA and CAT also blocked SO(2)-induced ROS production and [Ca(2+)](cyt) increase. However, EGTA and LaCl(3) can inhibit SO(2)-induced [Ca(2+)](cyt) increase, but cannot suppress SO(2)-induced ROS production. Our results indicate that high concentrations of SO(2) induce guard cell death via a PCD pathway through ROS mediating [Ca(2+)](cyt) elevation, which causes harmful effects to plants.
authors.affiliation: School of Life Science, Shanxi University, Taiyuan 030006, China.
authors.forename: Huilan
authors.initials: H
authors.lastname: Yi
authors.forename: Jingjing
authors.initials: J
authors.lastname: Yin
authors.forename: Xin
authors.initials: X
authors.lastname: Liu
authors.forename: Xiuqing
authors.initials: X
authors.lastname: Jing
authors.forename: Sanhong
authors.initials: S
authors.lastname: Fan
authors.forename: Hufang
authors.initials: H
authors.lastname: Zhang
mesh_terms: D000393:Air Pollutants / Q000633:toxicity*; D017209:Apoptosis / Q000187:drug effects; D002118:Calcium / Q000378:metabolism; D019441:Plant Epidermis / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000378:metabolism; D013458:Sulfur Dioxide / Q000633:toxicity*; D031306:Vicia / Q000187:drug effects* / Q000502:physiology
chemical_list: D000393:Air Pollutants; D017382:Reactive Oxygen Species; D013458:Sulfur Dioxide; D002118:Calcium