Deletion Analysis of AGD1 Reveals Domains Crucial for Its Plasma Membrane Recruitment and Function in Root Hair Polarity

The study investigated the role of AGD1, an ACAP-type ARF-GAP, in root hair polarity in Arabidopsis thaliana. AGD1-GFP localization varied with root hair growth phases, being prominent at the apical-most plasma membrane (PM) during slow growth phases and dissipating during rapid growth. Deletion analysis revealed that the pleckstrin homology (PH) domain was crucial for AGD1's PM localization, binding specifically to phosphoinositide-4-phosphate (PI(4)P). The study concluded that AGD1, through its PH domain, is recruited to the root hair PM by binding to PI(4)P, playing a role in regulating root hair growth and polarity.