Auxin efflux carrier ZmPGP1 mediates root growth inhibition under aluminum stress (Plant Physiology)

Acid soils (pH < 5.5) mobilize aluminum (Al) in the rhizosphere, which damages the root meristem and hinders exploration for nutrients and water. Zhang et al. demonstrate that a mutation in ZmPGP1, an auxin transport protein, imparts enhanced root growth under toxic Al conditions. The enhanced root growth is attributed to greater auxin accumulation, which leads to the upregulation of auxin response genes that sustain growth. Furthermore, organic acid membrane transporters, which help to mobilize Al in the rhizosphere, are upregulated in the mutant. (Summary by Nathan Scinto-Madonich), Plant Physiol. 10.1104/pp.17.01379