Hu, Y, Tian, S, Foyer, CH orcid.org/0000-0001-5989-6989 et al. (7 more authors) (2019) Efficient phloem transport significantly remobilizes cadmium from old to young organs in a hyperaccumulator Sedum alfredii. Journal of hazardous materials, 365. pp. 421-429. ISSN 0304-3894
Abstract
Our knowledge of cadmium (Cd) in hyperaccumulators mainly concerns root uptake, xylem translocation and foliar detoxification, while little attention has been paid to the role of phloem remobilization. We investigated Cd distribution in different organs of the hyperaccumulating ecotype (HE) of Sedum alfredii and compared its Cd phloem transport with that of the non-hyperaccumulating ecotype (NHE). In HE, results of micro X-ray fluorescence revealed that Cd preferentially accumulated in younger organs compared to the older, and its primary distribution sites changed from parenchyma to vascular/epidermal cells with increased organ age. Strong Cd signals in phloem cells were observed in HE old stems. Pre-stored Cd was readily exported from older to growing leaves, which could be accelerated by leaf senescence. Short-term feeding experiments showed that phloem-mediated Cd transport is rapid and efficient in HE. HE relocated 44% of the total leaf-labelled Cd to other organs, while over 90% Cd was retained in labelled leaves of NHE. High Cd was detected in HE phloem exudates but not in those from NHE leaves. In conclusion, Cd phloem transport is efficient and important for dominating the age-dependent Cd allocation in plants of HE S. alfredii.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | (c) 2018, Elsevier Ltd. All rights reserved. This is an author produced version of a paper published in Journal of hazardous materials. Uploaded in accordance with the publisher's self-archiving policy |
Keywords: | Cadmium; μ-XRF; Phloem; Remobilization; Age |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Biological Sciences (Leeds) > School of Biology (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 19 Dec 2018 14:33 |
Last Modified: | 09 Nov 2019 01:39 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.jhazmat.2018.11.034 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:140153 |
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