Metal tolerance proteins (MTPs) belong to the cation diffusion facilitator
family (CDF) and are involved in metal transport and homeostasis in
different plant species. A group of researchers from Centro de Investigación
y de Estudios Avanzados del Instituto Politécnico Nacional inMexico studied
a rice gene OsMTP11, which encodes a suspected CDF transporter that is
homologous to members of the Mn-CDF cluster.
The team, led by Aarón Barraza, found that the expression of OsMTP11 in the
Mn-sensitive yeast mutant pmr1 enhanced its manganese (Mn) tolerance. On the
other hand, knockdown of OsMTP11 resulted in growth inhibition under high
concentrations of Mn as well as increased accumulation of Mn in rice shoots
The overexpression of OsMTP11 in rice was found to enhance the plants' Mn
tolerance. Under a toxic level of Mn, the overexpressing rice lines
exhibited decreased Mn concentrations in their shoots and roots. Further
analysis revealed that the OsMTP11 protein is localized to the trans-Golgi
These findings suggest that OsMTP11 is a Mn transporter that is required for
Mn homeostasis and contributes towards Mn tolerance in rice.