Abstract Detail

Ecophysiology

Macfie, Sheila [1], Bahrami, Shirin [1], McGarvey, Brian [2].

Accumulation of cadmium in durum wheat: a role for phytochelatins?

Metal accumulation in edible plants is a world-wide concern and cadmium (Cd) accumulation in durum wheat (Triticum durum) is of particular concern. Pairs of near-isogenic lines of durum wheat have been developed in which one member of each pair accumulates two- to three-fold higher concentrations of Cd in the shoot and grain relative to the other member. These plant lines provide a good model system for identifying traits associated with root to shoot translocation of Cd. In this study, the relationship between phytochelatins and Cd translocation was investigated in five pairs of near-isogenic lines of durum wheat. The concentrations of Cd and six non-protein thiols (phytochelatins 2, 3, and 4 and their precursors: cysteine, gamma-glutamyl-cysteine and glutathione) were measured in roots and shoots on the eighth day of growth in environmentally-relevant concentrations of Cd. Three of the five pairs had the expected pattern of differential translocation of Cd from the roots. In one of these pairs, concentrations of cysteine and glutathione were positively correlated with the concentration of Cd in the roots and negatively correlated with concentrations of Cd in the shoots, and concentrations of phytochelatins 2 and 4 were positively correlated with concentrations of Cd in the shoots. However, in another one of these pairs concentrations of phytochelatins 2 and 4 were strongly negatively correlated with concentrations of Cd in the shoots and no correlations were found for cysteine or glutathione. In the third pair, as well as the two pairs that did not display the expected patterns of Cd distribution, concentrations of Cd were unrelated to the concentrations of any of the non-protein thiols. While the production of phytochelatins is a well-known response to Cd, the lack of a consistent relationship between Cd and non-protein thiols among the five pairs of near-isogenic lines indicates that neither phytochelatins nor their precursors play important roles in differential translocation of Cd from roots to shoots in durum wheat.

1 - University of Western Ontario, Biology, BGS Bldg, London, ON, N6G 5B7, Canada
2 - Southwest Unviersity for Nationalities, No. 16, South 4th Section, First ring Road, Chengdu, 610041, PR China

Keywords:
cadmium
durum wheat
non-protein thiols
phytochelatins.

Presentation Type: Poster:Posters for Topics
Session: P
Location: Hall D/The Shaw Conference Centre
Date: Monday, July 27th, 2015
Time: 5:30 PM
Number: PEP004
Abstract ID:486
Candidate for Awards:None