Modulation of AtPIP2;5 expression regulates root suberin synthesis and composition

Abstract

Root water uptake proceeds along both symplastic and apoplastic pathways. Aquaporins facilitate cellto- cell water transport, while suberization can hinder water flow through the apoplastic pathway. The increased root suberization observed in Arabidopsis plants overexpressing the AtPIP2;5 aquaporin, along with the reduced suberin content in the atpip2;5 knockout mutant, suggests that the relative contributions of both pathways to overall root water uptake can be coordinately regulated. Analyses of suberin monomer components revealed significant changes in C16 and C181 α,ω-diacids, alongside C181 and C22 ω-hydroxy acids, in AtPIP2;5-overexpressing plants compared to control plants (Arabidopsis thaliana, ecotype Col-0). These findings demonstrate a quantitative relationship between AtPIP2;5 expression and root suberization, indicating potential compensatory mechanisms between transcellular and apoplastic water-transport routes.