title: Thiol synthesis and arsenic hyperaccumulation in Pteris vittata (Chinese brake fern).
abstract: Pteris vittata (Chinese brake fern) has potential for phytoremediation of As-contaminated sites. In this study, the synthesis of total thiols and acid-soluble thiols in P. vittata was investigated under arsenic exposure. The strong and positive correlation between As concentration and acid-soluble thiols in plant leaflets suggests that acid-soluble thiols may play a role in As detoxification. A major As-induced thiol was purified and characterized. A molecular ion (M + 1) of 540 m/z suggests that the thiol was a phytochelatin (PC) with two base units (PC(2)). However, the ratios of acid-soluble thiols to As in leaflets exposed to As ranged from 0.012 to 0.026, suggesting that only a very small part of As is complexed by PC(2). PCs could play a minor detoxification role in this hyperaccumulator. A PC-independent mechanism appears to be mainly involved in As tolerance, while PC-dependent detoxification seems to be a supplement.
authors.affiliation: Department of Chemistry & Southeast Environmental Research Center, Florida International University, University Park, Miami, FL 33199, USA.
authors.forename: Weihua
authors.initials: W
authors.lastname: Zhang
authors.forename: Yong
authors.initials: Y
authors.lastname: Cai
authors.forename: Kelsey R
authors.initials: KR
authors.lastname: Downum
authors.forename: Lena Q
authors.initials: LQ
authors.lastname: Ma
mesh_terms: D001151:Arsenic / Q000378:metabolism*; D001673:Biodegradation, Environmental; D004787:Environmental Pollution; D032495:Pteris / Q000378:metabolism*; D012989:Soil Pollutants / Q000032:analysis / Q000378:metabolism*; D013438:Sulfhydryl Compounds / Q000032:analysis / Q000378:metabolism*
chemical_list: D012989:Soil Pollutants; D013438:Sulfhydryl Compounds; D001151:Arsenic