Journal
JOURNAL OF EXPERIMENTAL BOTANY
Volume 68, Issue 9, Pages 2387-2398Publisher
OXFORD UNIV PRESS
DOI: 10.1093/jxb/erx112
Keywords
Cadmium; fluorescence microscopy; localization; micro X-ray fluorescence; protoplasts; tolerance; vacuole
Categories
Funding
- National Natural Science Foundation of China [31370040, 41401366]
- Zhejiang Provincial Natural Science Foundation of China [LR14C150001]
- Foundation for the Author of National Excellent Doctoral Dissertation of PR China [201469]
- China Geological Survey [12120113015400]
- DOE Office of Science [DE-AC02-06CH11357]
- U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences [DE-AC02-76SF00515]
Ask authors/readers for more resources
Sedum alfredii is one of a few plant species known to hyperaccumulate cadmium (Cd). Uptake, localization, and tolerance of Cd at cellular levels in shoots were compared in hyperaccumulating ( HE) and non-hyperaccumulating (NHE) ecotypes of Sedum alfredii. X-ray fluorescence images of Cd in stems and leaves showed only a slight Cd signal restricted within vascular bundles in the NHEs, while enhanced localization of Cd, with significant tissue- and age-dependent variations, was detected in HEs. In contrast to the vascular-enriched Cd in young stems, parenchyma cells in leaf mesophyll, stem pith and cortex tissues served as terminal storage sites for Cd sequestration in HEs. Kinetics of Cd transport into individual leaf protoplasts of the two ecotypes showed little difference in Cd accumulation. However, far more efficient storage of Cd in vacuoles was apparent in HEs. Subsequent analysis of cell viability and hydrogen peroxide levels suggested that HE protoplasts exhibited higher resistance to Cd than those of NHE protoplasts. These results suggest that efficient sequestration into vacuoles, as opposed to rapid transport into parenchyma cells, is a pivotal process in Cd accumulation and homeostasis in shoots of HE S. alfredii. This is in addition to its efficient root-to-shoot translocation of Cd.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available