Phytohormonal Responses to Soil Acidity in Plants

Phytohormones play an important role in plant growth and adaptation to various environmental stresses. Acid soils are recognized as one of the most important abiotic stresses, limiting plant growth and reducing crop yield. Furthermore, acid soils can cause changes in phytohormone metabolism such as biosynthesis and action. Thus, in this chapter, we provide a critical overview focused on phytohormone responses, plant hormone balance, and cross-interactions to nutrients and acid soils, including low pH stress (or high H+ toxicity) and low pH-induced aluminum toxicity.