Elevated Expression of Vacuolar Nickel Transporter Gene IREG2 Is Associated With Reduced Root-to-Shoot Nickel Translocation in Noccaea japonica
A number of metal hyperaccumulator plants, including nickel (Ni) hyperaccumulators, have been identified in the genus . The ability to accumulate Ni in shoots varies widely among species and ecotypes in this genus; however, little is known about the molecular mechanisms underlying this intra- and in...
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Published in | Frontiers in plant science Vol. 11; p. 610 |
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Main Authors | , , , , , , |
Format | Journal Article |
Language | English |
Published |
Switzerland
Frontiers Media S.A
03.06.2020
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Subjects | |
Online Access | Get full text |
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Summary: | A number of metal hyperaccumulator plants, including nickel (Ni) hyperaccumulators, have been identified in the genus
. The ability to accumulate Ni in shoots varies widely among species and ecotypes in this genus; however, little is known about the molecular mechanisms underlying this intra- and inter-specific variation. Here, in hydroponic culture, we compared Ni accumulation patterns between
, which originated in Ni-enriched serpentine soils in Mt. Yubari (Hokkaido, Japan), and
ecotype Ganges, which originated in zinc/lead-mine soils in Southern France. Both
species showed extremely high Ni tolerance compared with that of the non-accumulator
. But, following treatment with 200 μM Ni,
showed leaf chlorosis, whereas
did not show any stress symptoms. Shoot Ni concentration was higher in
than in
; this difference was due to higher efficiency of root-to-shoot Ni translocation in
than
. It is known that the vacuole Ni transporter IREG2 suppresses Ni translocation from roots to shoots by sequestering Ni in the root vacuoles. The expression level of the
gene in the roots of
was 10-fold that in the roots of
. Moreover, the copy number of
per genome was higher in
than in
, suggesting that
expression is elevated by gene multiplication in
. The heterologous expression of
of
and
in yeast and
confirmed that both
genes encode functional vacuole Ni transporters. Taking these results together, we hypothesize that the elevation of
expression by gene multiplication causes the lower root-to-shoot Ni translocation in
. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 Edited by: Tomoko Nozoye, Meiji Gakuin University, Japan Reviewed by: Fumihiko Sato, Kyoto University, Japan; Marc Hanikenne, University of Liège, Belgium This article was submitted to Plant Traffic and Transport, a section of the journal Frontiers in Plant Science |
ISSN: | 1664-462X 1664-462X |
DOI: | 10.3389/fpls.2020.00610 |