Pollutant-induced cell death and reactive oxygen species accumulation in the aerial roots of Chinese banyan (Ficus microcarpa).
Industrial pollutants induce the production of toxic reactive oxygen species (ROS) such as O2.-, H2O2, and·OH in plants, but they have not been well quantified or localized in tissues and cells. This study evaluated the pollutant- (HSO3-, NH4NO3, Al3+, Zn2+, and Fe2+) induced toxic effects of ROS on the aerial roots of Chinese banyan (Ficus microcarpa). Root cell viability was greatly reduced by treatment with 20 mM NaHSO3, 20 mM NH4NO3, 0.2 mM AlCl3, 0.2 mM ZnSO4, or 0.2 mM FeSO4. Biochemical assay and histochemical localization showed that O2.-accumulated in roots in response to pollutants, except that the staining of O2.-under NaHSO3treatment was not detective. Cytochemical localization further indicated that the generated O2.-was present mainly in the root cortex, and pith cells, especially in NH4NO3- and FeSO4-treated roots. The pollutants also caused greatly accumulated H2O2and·OH in aerial roots, which finally resulted in lipid peroxidation as indicated by increased malondialdehyde contents. We conclude that the F. microcarpa aerial roots are sensitive to pollutant-induced ROS and that the histochemical localization of O2.-via nitrotetrazolium blue chloride staining is not effective for detecting the effects of HSO3-treatment because of the treatment's bleaching effect.
Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650 China.
Nan
N
Liu
Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650 China.|University of the Chinese Academy of Sciences, Beijing, 100049 China.
Ce
C
Cao
Guangdong Open Laboratory of Geospatial Information Technology and Application, Guangzhou Institute of Geography, Guangzhou, 510070 China.
Zhongyu
Z
Sun
Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650 China.
Zhifang
Z
Lin
Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650 China.
Rufang
R
Deng
D016923:Cell Death / Q000187:drug effects; D004785:Environmental Pollutants / Q000378:metabolism* / Q000633:toxicity; D030681:Ficus / Q000166:cytology / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000378:metabolism; D017665:Hydroxyl Radical / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects; D008315:Malondialdehyde / Q000378:metabolism; D018517:Plant Roots / Q000166:cytology / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism*
D004785:Environmental Pollutants; D017382:Reactive Oxygen Species; D017665:Hydroxyl Radical; D008315:Malondialdehyde; D006861:Hydrogen Peroxide