Throwing Copper Around: How Plants Control Uptake, Distribution, and Accumulation of Copper

Copper (Cu) is essential to plants but can also be harmful due to Fenton chemistry. Because of that, it is necessary to keep Cu within a narrow concentration limit. Plants evolved mechanisms to sense Cu and precisely regulate uptake and accumulation to avoid both deficiency and toxicity. However, plants experience variable Cu levels in soils, both due to natural environments as well as human's-based farming practices that can lead to Cu accumulation in soils. Therefore, we need to understand Cu homeostasis. Here, we review how Cu is found in soils; Cu toxicity responses in plants; the role of Cu transporters, described mainly in model species such as Arabidopsis thaliana and Oryza sativa; the crosstalk between Cu and iron (Fe) homeostasis; Cu hyperaccumulator plants; and discuss some gaps and future directions, which can improve our understanding in the field.