Synthetic phytochelatins complement a phytochelatin-deficient Arabidopsis mutant and enhance the accumulation of heavy metal(loid)s

• Published in: Biochemical and biophysical research communications 2013-05, Vol.434 (3), p.664-669
• Main Authors: Shukla, Devesh, Tiwari, Manish, Tripathi, Rudra D., Nath, Pravendra, Trivedi, Prabodh Kumar
• Format: Article
• Language: English
• Subjects: Arabidopsis; Arabidopsis - genetics; Arabidopsis - metabolism; Cad1-3 mutant; Cloning, Molecular; Genes, Plant; Genetic Complementation Test; Heavy metal(loid); Metals, Heavy - metabolism; Mutant complementation; Mutation; Phytochelatins - pharmacology; Phytoremediation; Synthetic phytochelatin; Transcriptional Activation
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2013.03.138

•Artificial genes (ECs) encoding synthetic phytochelatin designed and expressed in Arabidopsis.•Expression of these genes rescued sensitivity of Arabidopsis cad1-3 mutant to heavy metals.•Expression in Arabidopsis led to sensitive phenotype to heavy metals.•Arabidopsis lines expressing EC genes displayed enhanced heavy metal accumulation. Phytochelatins (PCs) are naturally occurring thiol-rich peptides containing gamma (γ) peptide bonds and are well known for their metal-binding and detoxification capabilities. Whether synthetic phytochelatins (ECs) can be used as an alternative approach for enhancing the metal-binding capacity of plants has been investigated in this study. The metal-binding potential of ECs has been demonstrated in bacteria; however, no report has investigated the expression of ECs in plants. We have expressed three synthetic genes encoding ECs of different lengths in wild type (WT) Arabidopsis (Col-0 background) and a phytochelatin-deficient Arabidopsis mutant (cad1-3). After exposure to different heavy metals, the transgenic plants were examined for phenotypic changes, and metal accumulation was evaluated. The expression of EC genes rescued the sensitive phenotype of the cad1-3 mutant under heavy metal(loid) stress. Transgenic Arabidopsis plants expressing EC genes accumulated a significantly enhanced level of heavy metal(loid)s in comparison with the WT plant. The mutant complementation and enhanced heavy metal(loid) accumulation in the transgenic Arabidopsis plants suggest that ECs work in a manner similar to that of PCs in plants and that ECs could be used as an alternative for phytoremediation of heavy metal(loid) exposure.