Plant Cell, Tissue and Organ Culture

, Volume 88, Issue 2, pp 201–216

Changes in phytochelatins and their biosynthetic intermediates in red spruce (Picea rubens Sarg.) cell suspension cultures under cadmium and zinc stress

Original Paper

DOI: 10.1007/s11240-006-9192-1

Cite this article as:
Thangavel, P., Long, S. & Minocha, R. Plant Cell Tiss Organ Cult (2007) 88: 201. doi:10.1007/s11240-006-9192-1

Abstract

Cell suspension cultures of red spruce (Picea rubens Sarg.) were selected to study the effects of cadmium (Cd) and zinc (Zn) on phytochelatins (PCs) and related metabolites after 24 h exposure. The PC2 and its precursor, γ-glutamylcysteine (γ-EC) increased two to fourfold with Cd concentrations ranging from 12.5 to 200 μM as compared to the control. However, Zn-treated cells showed a less than twofold increase in γ-EC and PC2 levels as compared to the control even at the highest concentration of 800 μM. In addition, unidentified higher chain PCs were also found in both the Cd and Zn treated cells and they increased significantly with increasing concentrations of Cd and Zn. The cellular ratio of PC2 : Cd or Zn content clearly indicated that Cd (with ratios ranging from 0.131 to 0.546) is a more effective inducer of PC2 synthesis/accumulation than Zn (with ratios ranging from 0.032 to 0.102) in red spruce cells. A marginal decrease in glutathione (GSH) was observed in both Cd and Zn treated cells. However, the GSH precursor, cysteine, declined twofold with all Cd concentrations while the decrease with Zn was 1.5–2-fold only at the higher treatment concentrations of Zn as compared to control. In addition, changes in other free amino acids, polyamines, and inorganic ions were also studied. These results suggest that PCs and their biosynthetic intermediates play a significant role in red spruce cells protecting against Cd and Zn toxicity.

Keywords

Amino acidsCysteineγ-GlutamylcysteineGlutathioneHeavy metalsHPLCInorganic ionsMetal detoxificationPolyamines

Abbreviations

ACN

Acetonitrile

γ-EC

γ-glutamylcysteine

GSH

Glutathione

HPLC

High-performance liquid chromatography

mBBr

Monobromobimane

NAC

N-acetyl-l-cysteine

PCs

Phytochelatins

TFA

Trifluroacetic acid

Copyright information

© Springer Science+Business Media B.V. 2006

Authors and Affiliations

  1. 1.Northern Research StationUSDA Forest ServiceDurhamUSA