Molecular mechanisms of plant adaptation to acid soils: A review

Acid soils are widespread and limit plant production globally. Aluminum (Al) and manganese (Mn) toxicity, as well as phosphorus (P) deficiency, are the major limiting factors affecting plant growth and productivity on acid soils. Plants have evolved various strategies to adapt to these stresses. These strategies include using both external and internal mechanisms to adapt to Al toxicity, regulating Mn uptake, translocation, and distribution to avoid Mn toxicity, and orchestrating a set of P transport mechanisms to efficiently take up P from the soil. Here, we review the current state of knowledge about the molecular mechanisms of plant adaptation to these constraints on acid soils, focusing on the roles of transporters involved in Al/Mn tolerance and P efficiency. Manipulating these genes combined with biotechnology will contribute to developing novel strategies for improving plant adaptation to acid soils. The molecular mechanisms by which plants co-adapt to multiple stresses on acid soils are largely unknown and required to be further investigated.