The hypothesis that hyperaccumulation of certain metals in plants may play a role in osmotic adjustment under water stress (drought) was tested in the context of nickel hyperaccumulator Stackhousia tryonii. Field-collected mature plants of S. tryonii, grown in native ultramafic soil, were pruned to soil level and the re-growth exposed to five levels of water stress (20, 40, 60, 80 and 100% field capacity; FC) for 20 weeks. Water stress had significant (P<0.05) influence on growth (biomass), water potential and shoot Ni concentrations, with progressively more impact as water stress was increased from 80 to 40% FC. Shoot Ni concentration increased significantly from 3,400 ug g-1 dry weight (at 100% FC) to 9,400 ug g-1 dry weight (at 20% FC). Assuming that Ni is uniformly distributed through the shoot tissue, the Ni concentration could account for 100% at the 80 and 60% FC conditions, and 50% at the 40 and 20% FC conditions of plant osmotic regulation. The results are consistent with a role of Ni in osmotic adjustment and protection of S. tryonii plants against drought.
Funding
Category 1 - Australian Competitive Grants (this includes ARC, NHMRC)
History
Volume
223
Issue
1
Start Page
134
End Page
139
Number of Pages
6
eISSN
0032-0935
ISSN
0032-0935
Location
New York
Publisher
Springer Verlag
Language
en-aus
Peer Reviewed
Yes
Open Access
No
External Author Affiliations
Faculty of Arts, Health and Sciences; TBA Research Institute; University of Melbourne;