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Functional characterisation of two phytochelatin synthases in rice ( Oryza sativa cv. Milyang 117) that respond to cadmium stress
Author(s) -
Park H. C.,
Hwang J. E.,
Jiang Y.,
Kim Y. J.,
Kim S. H.,
Nguyen X. C.,
Kim C. Y.,
Chung W. S.
Publication year - 2019
Publication title -
plant biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.871
H-Index - 87
eISSN - 1438-8677
pISSN - 1435-8603
DOI - 10.1111/plb.12991
Subject(s) - phytochelatin , biology , arabidopsis thaliana , saccharomyces cerevisiae , cadmium , oryza sativa , mutant , yeast , gene , biochemistry , strain (injury) , arabidopsis , botany , genetics , microbiology and biotechnology , enzyme , glutathione , chemistry , organic chemistry , anatomy
Cadmium (Cd) is one of the most toxic heavy metals and a non‐essential element to all organisms, including plants; however, the genes involved in Cd resistance in plants remain poorly characterised. To identify Cd resistance genes in rice, we screened a rice cDNA expression library treated with CdCl 2 using a yeast ( Saccharomyces cerevisiae ) mutant ycf1 strain ( DTY 167) and isolated two rice phytochelatin synthases ( Os PCS 5 and Os PCS 15 ). The genes were strongly induced by Cd treatment and conferred increased resistance to Cd when expressed in the ycf1 mutant strain. In addition, the Cd concentration was twofold higher in yeast expressing Os PCS 5 and Os PCS 15 than in vector‐transformed yeast, and Os PCS 5 and Os PCS 15 localised in the cytoplasm. Arabidopsis thaliana plants overexpressing Os PCS 5/‐15 paradoxically exhibited increased sensitivity to Cd, suggesting that overexpression of Os PCS 5/‐15 resulted in toxicity due to excess phytochelatin production in A. thaliana . These data indicate that Os PCS 5 and Os PCS 15 are involved in Cd tolerance, which may be related to the relative abundances of phytochelatins synthesised by these phytochelatin synthases.