Glycine-Rich RNA-Binding Protein Functions in Nickel and Lead Tolerance in .

Plant glycine-rich RNA-binding proteins (GRPs) play crucial roles in the response to environmental stresses. However, the functions of in plants under heavy metal stress remain unclear. In the present study, in , the transcript level of was markedly increased by Ni but was decreased by Pb. -overexpressing plants improved Ni tolerance, whereas the knockout mutant () was more susceptible than the wild type to Ni. In addition, showed greatly enhanced Pb tolerance, whereas overexpression lines showed high Pb sensitivity. Ni accumulation was reduced in overexpression lines but increased in , whereas Pb accumulation in was lower than that in overexpression lines. Ni induced glutathione synthase genes and in overexpression lines, whereas Pb increased metallothionein genes and and phytochelatin synthase genes and in . Furthermore, Ni increased and in , whereas Pb significantly induced and in overexpression lines. The mRNA stability of and was directly regulated by AtGRP7 under Ni and Pb, respectively. Collectively, these results indicate that plays a crucial role in Ni and Pb tolerance by reducing Ni and Pb accumulation and the direct or indirect post-transcriptional regulation of genes related to heavy metal chelators and antioxidant enzymes.