Metal tolerance proteins (MTPs), which belong to the cation diffusion
facilitator family (CDF), have been known to be involved in metal transport
and homeostasis in different plant species. The team of Gang Ma from Nanjing
Agricultural University in China recently studied the role of the rice gene
OsMTP11, which encodes a CDF.
The team found that expression of OsMTP11 enhances manganese (Mn) tolerance
in the Mn-sensitive yeast mutant. Meanwhile, knockdown of OsMTP11 in rice
resulted in growth inhibition due to the presence of high concentrations of
Mn, leading to increased accumulation of Mn in the shoots and roots.
Overexpression of OsMTP11 was found to enhance Mn tolerance in rice, even
under a toxic level of Mn. Analysis revealed that the OsMTP11 protein is
localized to the trans-Golgi network (TGN), and regulates Mn relocalization
under high levels of Mn.
These suggest that OsMTP11 protein is required for Mn homeostasis and
contributes towards Mn tolerance in rice.