Functional significance of AtHMA4 C-terminal domain in planta
Functional significance of AtHMA4 C-terminal domain in planta
Background: Enhancing the upward translocation of heavy metals such as Zn from root to shoot through genetic engineering has potential for biofortification and phytoremediation. This study examined the contribution of the heavy metal-transporting ATPase, AtHMA4, to the shoot ionomic profile of soil-grown plants, and investigated the importance of the C-terminal domain in the functioning of this transporter.
Principal Findings: The Arabidopsis hma2 hma4 mutant has a stunted phenotype and a distinctive ionomic profile, with low shoot levels of Zn, Cd, Co, K and Rb, and high shoot Cu. Expression of AtHMA4 (AtHMA4-FL) under the CaMV-35S promoter partially rescued the stunted phenotype of hma2 hma4; rosette diameter returned to wild-type levels in the majority of lines and bolts were also produced, although the average bolt height was not restored completely. AtHMA4-FL expression rescued Co, K, Rb and Cu to wild-type levels, and partially returned Cd and Zn levels (83% and 28% of wild type respectively). In contrast, expression of AtHMA4-trunc (without the C-terminal region) in hma2 hma4 only partially restored the rosette diameter in two of five lines and bolt production was not rescued. There was no significant effect on the shoot ionomic profile, apart from Cd, which was increased to 41% of wild-type levels. When the AtHMA4 C-terminal domain (AtHMA4-C-term) was expressed in hma2 hma4 it had no marked effect. When expressed in yeast, AtHMA4-C-term and AtHMA4-trunc conferred greater Cd and Zn tolerance than AtHMA4-FL.
Conclusion: The ionome of the hma2 hma4 mutant differs markedly from wt plants. The functional relevance of domains of AtHMA4 in planta can be explored by complementing this mutant. AtHMA4-FL is more effective in restoring shoot metal accumulation in this mutant than a C-terminally truncated version of the pump, indicating that the C-terminal domain is important in the functioning of AtHMA4 in planta.
e13388
Mills, Rebecca F.
dec4afc8-be3b-4517-9038-c3c3e8b71b35
Valdes, Billy
41564ec2-2394-4fdf-aaf4-26f18c3e1e42
Duke, Michael
e39d932b-9331-49c8-800c-413dbfa7059a
Peaston, Kerry A.
55c75e49-e55d-441c-a07e-867e1fa000e7
Lahner, Brett
87924f99-d22a-4cec-b90b-bcda45a39af2
Salt, David E.
f0f1cf37-6d40-4c39-86e4-ec88ed9ec66e
Williams, Lorraine E.
79ee1856-3732-492b-8ac5-239749c85d9e
20 October 2010
Mills, Rebecca F.
dec4afc8-be3b-4517-9038-c3c3e8b71b35
Valdes, Billy
41564ec2-2394-4fdf-aaf4-26f18c3e1e42
Duke, Michael
e39d932b-9331-49c8-800c-413dbfa7059a
Peaston, Kerry A.
55c75e49-e55d-441c-a07e-867e1fa000e7
Lahner, Brett
87924f99-d22a-4cec-b90b-bcda45a39af2
Salt, David E.
f0f1cf37-6d40-4c39-86e4-ec88ed9ec66e
Williams, Lorraine E.
79ee1856-3732-492b-8ac5-239749c85d9e
Mills, Rebecca F., Valdes, Billy, Duke, Michael, Peaston, Kerry A., Lahner, Brett, Salt, David E. and Williams, Lorraine E.
(2010)
Functional significance of AtHMA4 C-terminal domain in planta.
PLoS ONE, 5 (10), .
(doi:10.1371/journal.pone.0013388).
(PMID:20975991)
Abstract
Background: Enhancing the upward translocation of heavy metals such as Zn from root to shoot through genetic engineering has potential for biofortification and phytoremediation. This study examined the contribution of the heavy metal-transporting ATPase, AtHMA4, to the shoot ionomic profile of soil-grown plants, and investigated the importance of the C-terminal domain in the functioning of this transporter.
Principal Findings: The Arabidopsis hma2 hma4 mutant has a stunted phenotype and a distinctive ionomic profile, with low shoot levels of Zn, Cd, Co, K and Rb, and high shoot Cu. Expression of AtHMA4 (AtHMA4-FL) under the CaMV-35S promoter partially rescued the stunted phenotype of hma2 hma4; rosette diameter returned to wild-type levels in the majority of lines and bolts were also produced, although the average bolt height was not restored completely. AtHMA4-FL expression rescued Co, K, Rb and Cu to wild-type levels, and partially returned Cd and Zn levels (83% and 28% of wild type respectively). In contrast, expression of AtHMA4-trunc (without the C-terminal region) in hma2 hma4 only partially restored the rosette diameter in two of five lines and bolt production was not rescued. There was no significant effect on the shoot ionomic profile, apart from Cd, which was increased to 41% of wild-type levels. When the AtHMA4 C-terminal domain (AtHMA4-C-term) was expressed in hma2 hma4 it had no marked effect. When expressed in yeast, AtHMA4-C-term and AtHMA4-trunc conferred greater Cd and Zn tolerance than AtHMA4-FL.
Conclusion: The ionome of the hma2 hma4 mutant differs markedly from wt plants. The functional relevance of domains of AtHMA4 in planta can be explored by complementing this mutant. AtHMA4-FL is more effective in restoring shoot metal accumulation in this mutant than a C-terminally truncated version of the pump, indicating that the C-terminal domain is important in the functioning of AtHMA4 in planta.
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Published date: 20 October 2010
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Biological Sciences
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Local EPrints ID: 186095
URI: http://eprints.soton.ac.uk/id/eprint/186095
ISSN: 1932-6203
PURE UUID: bb5dbfc6-61b3-4d53-9cb6-8f7eb0ec39a7
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Date deposited: 12 May 2011 10:39
Last modified: 14 Mar 2024 03:17
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Author:
Rebecca F. Mills
Author:
Billy Valdes
Author:
Michael Duke
Author:
Kerry A. Peaston
Author:
Brett Lahner
Author:
David E. Salt
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