Developmental Responses of Root Hairs to Mg Deficiency

Magnesium (Mg), an essential element for plants is easily leached in acidic and sandy soils. Magnesium deficiency induces the initiation and elongation of root hairs, which allows the plant roots to acquire more Mg under Mg-limited conditions. However, the signals involved in the regulatory cascade leading to the induction of root hair development under Mg deficiency are largely unknown to date. Recent studies have revealed that many chemical signal molecules such as ethylene, nitric oxide, auxin, reactive oxygen, and calcium regulate the root hair development induced owing to Mg deficiency. This mini-review intends to briefly discuss the role of these chemical signals in the induction of root hair development under Mg-deficient conditions.