Genome-wide identification of PHYTOCHELATIN and PHYTOCH_SYNTH domain-containing phytochelatin family from rice

摘要

Phytochelatin synthases (PCS) are cytosol proteins that may play vital roles in heavy metal detoxicity in bacteria, yeasts, plants, or worms. More than 10 PCS-encoded genes from different species have been reported during the last decade, and they were played critical roles in cadmium or arsine detoxfication. In this investigation, we identified 3 putative PCS and 11 putative PCS-like genes in rice genome by the bioinformatics analysis of recently completed rice genome data, classified them into 2 subfamilies on the basis of domain sequence similarity by constructing phylogenetic trees, and localized them in rice chromosomes. Reverse transcription polymerase chain reaction (RT-PCR) was performed to demonstrate that the expression of 3 putative PCS genes (OsPCS3, OsPCS8, and OsPCS11) could not be detected in the roots, stem base, nodes, internodes or petioles, but all the remaining 11 putative rice PCS genes were found to be expressed in the leaves and panicles, OsPCS7 was induced by Hg2+ and Pb2+, while OsPCS9 was induced by Cd2+ and Zn2+ in roots, suggesting that PCS or PCS-like genes might play crucial roles in survival or in different heavy metal detoxification.