Molybdenum: More than an essential element.

Molybdenum (Mo) is an essential element for almost all living organisms. After being taken up into the cells as molybdate, Mo is incorporated into the molybdenum cofactor, which functions as the active site of several molybdenum-requiring enzymes and thus plays crucial roles in multiple biological processes. The uptake and transport of molybdate is mainly mediated by two types of molybdate transporters. The homeostasis of Mo in plants cells is tightly controlled and such homeostasis likely plays vital roles for plants to adapt to local environment. Recent evidence suggests that Mo is more than an essential element required for plant growth and development but is also involved in local adaptation to coastal salinity environment. In this review, we summarize recent research progress on the molybdate uptake and transport, molybdenum homeostasis network in plants and discuss the potential roles of molybdate transporter in plant adaptation to local environment.