Abstract
AbstractManganese (Mn) is an essential mineral nutrient. Mn transport proteins have a critical role in mediating acquisition of Mn by the roots, partitioning Mn into organelles such as the vacuole and chloroplast, controlling the long-distance translocation of Mn, and regulating Mn loading into organs such as leaves, flowers and seeds. Mn transporters also play a major role in providing tolerance to toxic concentrations of Mn, by mediating sequestration into internal cellular compartments or efflux from the cell, and have been implicated in adaptive strategies to overcome Mn deficiency. Recently, members of various metal transporter families involved in Mn transport have been identified. These include members of the ZIP, Nramp, CAX, CDF, OPT/YSL and P-type ATPase transporter families. An emerging feature of many plant Mn transporters, particularly those involved in cytosolic Mn influx, is their broad substrate selectivity, often coupled with iron (Fe) transport and regulated by Fe deficiency. In contrast, some of the transporters that mediate Mn sequestration into the vacuole, such as the Mn2+/H+ antiporters CAX2 and ShMTP1, appear to be more specific for Mn and are not influenced by Fe nutrition. This review describes the characterisation of these putative Mn transporters, and discusses their potential roles in various physiological processes. The genetic manipulation of Mn transport and homeostasis proteins as a strategy to overcome plant Mn stress, and the identification and characterisation of Mn homeostasis mutants and Mn hyperaccumulator plants as a means to identify novel components in Mn homeostasis, is also discussed.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call