TY - JOUR
T1 - Lead, zinc and iron (Fe2+) tolerances in wetland plants and relation to root anatomy and spatial pattern of ROL
AU - Deng, H.
AU - Ye, Z. H.
AU - Wong, M. H.
N1 - Funding Information:
The study was supported by the Research Council of University Grants Committee, Hong Kong (RGC ref: HKBU-2072/01 M). The authors would like to thank Prof. W. Armstrong (Hull University, UK) for letting us use his instruments for ROL measurement and Dr. T.D. Colmer (The University of Western Australia, Australia) for his help in ROL measurement and advice.
PY - 2009/3
Y1 - 2009/3
N2 - Metal (Pb, Zn and Fe2+) tolerances, root anatomy and profile of radial oxygen loss (ROL) along the root (i.e., spatial pattern of ROL) were studied in 10 emergent wetland plants. The species studied could be classified into three groups. Group I included Alternanthera philoxeroides, Beckmannia syzigachne, Oenanthe javanica and Polypogon fugax, with high ROL along the whole length of root ('partial barrier' to ROL). Group II included Cyperus flabelliformis, Cyperus malaccensis, Juncus effusus, Leersia hexandra and Panicum paludosum, ROL of which was remarkably high just behind the root apex, but decreased significantly at relatively basal regions ('tight barrier' to ROL). Group III consisted of only Neyraudia reynaudiana, with extremely low ROL along the length of root. The results indicated that metal tolerance in wetland plants was related to root anatomy and spatial pattern of ROL. Co-evolution of metal (Fe and Zn) tolerance and flood tolerance possibly developed in wetland plants since species showing a 'tight barrier' to ROL (a common trait of flood-tolerant species) in basal root zones had higher Fe and Zn tolerances than those showing a 'partial barrier'. Root anatomy such as lignin and suberin deposition contributed to a 'tight barrier' in root and conferred to exclusion ability in tolerant species.
AB - Metal (Pb, Zn and Fe2+) tolerances, root anatomy and profile of radial oxygen loss (ROL) along the root (i.e., spatial pattern of ROL) were studied in 10 emergent wetland plants. The species studied could be classified into three groups. Group I included Alternanthera philoxeroides, Beckmannia syzigachne, Oenanthe javanica and Polypogon fugax, with high ROL along the whole length of root ('partial barrier' to ROL). Group II included Cyperus flabelliformis, Cyperus malaccensis, Juncus effusus, Leersia hexandra and Panicum paludosum, ROL of which was remarkably high just behind the root apex, but decreased significantly at relatively basal regions ('tight barrier' to ROL). Group III consisted of only Neyraudia reynaudiana, with extremely low ROL along the length of root. The results indicated that metal tolerance in wetland plants was related to root anatomy and spatial pattern of ROL. Co-evolution of metal (Fe and Zn) tolerance and flood tolerance possibly developed in wetland plants since species showing a 'tight barrier' to ROL (a common trait of flood-tolerant species) in basal root zones had higher Fe and Zn tolerances than those showing a 'partial barrier'. Root anatomy such as lignin and suberin deposition contributed to a 'tight barrier' in root and conferred to exclusion ability in tolerant species.
KW - China
KW - Metal tolerance
KW - Radial oxygen loss (ROL)
KW - Root aerenchyma
KW - Wetland plants
UR - http://www.scopus.com/inward/record.url?scp=58649113407&partnerID=8YFLogxK
U2 - 10.1016/j.envexpbot.2008.10.005
DO - 10.1016/j.envexpbot.2008.10.005
M3 - Journal article
AN - SCOPUS:58649113407
SN - 0098-8472
VL - 65
SP - 353
EP - 362
JO - Environmental and Experimental Botany
JF - Environmental and Experimental Botany
IS - 2-3
ER -