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Variation in root‐to‐shoot translocation of cadmium and zinc among different accessions of the hyperaccumulators Thlaspi caerulescens and Thlaspi praecox
Author(s) -
Xing J. P.,
Jiang R. F.,
Ueno D.,
Ma J. F.,
Schat H.,
McGrath S. P.,
Zhao F. J.
Publication year - 2008
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.2008.02376.x
Subject(s) - hyperaccumulator , chromosomal translocation , shoot , biology , apoplast , botany , cadmium , phytoremediation , cell wall , gene , chemistry , genetics , ecology , organic chemistry , contamination
Summary• Efficient root‐to‐shoot translocation is a key trait of the zinc/cadmium hyperaccumulators Thlaspi caerulescens and Thlaspi praecox , but the extent of variation among different accessions and the underlying mechanisms remain unclear. • Root‐to‐shoot translocation of Cd and Zn and apoplastic bypass flow were determined in 10 accessions of T. caerulescens and one of T. praecox , using radiolabels 109 Cd and 65 Zn. Two contrasting accessions (Pr and Ga) of T. caerulescens were further characterized for TcHMA4 expression and metal compartmentation in roots. • Root‐to‐shoot translocation of 109 Cd and 65 Zn after 1 d exposure varied 4.4 to 5‐fold among the 11 accessions, with a significant correlation between the two metals, but no significant correlation with uptake or the apoplastic bypass flow. The F 2 progeny from a cross between accessions from Prayon, Belgium (Pr) and Ganges, France (Ga) showed a continuous phenotype pattern and transgression. There was no significant difference in the TcHMA4 expression in roots between Pr and Ga. Compartmentation analysis showed a higher percentage of 109 Cd sequestered in the root vacuoles of Ga than Pr, the former being less efficient in translocation than the latter. • Substantial natural variation exists in the root‐to‐shoot translocation of Cd and Zn, and root vacuolar sequestration may be an important factor related to this variation.