Polyphenol Oxidase Activity in Subcellular Fractions of Tall Fescue Contaminated by Polycyclic Aromatic Hydrocarbons
- Wanting Lingab,
- Xiaodan Lua,
- Yanzheng Gao *a,
- Juan Liua and
- Yandi Suna
- a Institute of Organic Contaminant Control and Soil Remediation, College of Resource and Environmental Sciences, Nanjing Agricultural Univ., Nanjing 210095, P.R. China
b State Key Lab. of Pollution Control and Resources Reuse, Nanjing Univ., Nanjing 210093, P.R. China. Assigned to Associate Editor Keith Goyne
Understanding enzyme responses to contamination with persistent organic pollutants (POPs) is a key step in the elucidation of POP metabolic mechanisms in plants. However, there is little information available on enzyme activity in subcellular fractions of POP-contaminated plants. To our knowledge, this is the first study to investigate the activities of polyphenol oxidase (PPO) in cell fractions of plants under contamination stress from polycyclic aromatic hydrocarbons (PAHs) using a greenhouse batch technique. Three parameters, Ecell, Ecell-n, and Pcell, denoting the amount of PPO activity, cell fraction content–normalized PPO activity, and proportion of PPO activity in each cell fraction, respectively, were used in this study. Contamination with phenanthrene, as a representative PAH, at a relatively high level (>0.23 mg L−1) in culture solution generally stimulated PPO activity in tall fescue (Festuca arundinacea Schreb.) roots and shoots and their cellular fractions. The amount and distribution proportion of PPO activity in each cell fraction of phenanthrene-contaminated roots and shoots were (in descending order): cell solution > > cell wall > cell organelles. Cell solution was the dominant storage domain of PPO activity and contributed 84.0 and 82.8% of PPO activity in roots and shoots, respectively. The cell wall had the highest density of PPO activity in roots and shoots, based on the highest cell fraction content normalized PPO activity in this cell fraction. Our results provide new information on enzyme responses in plant intracellular fractions to xenobiotic POPs and fundamental information on within-plant POP metabolic mechanisms.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
Copyright © 2012. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.