Auxin Homeostasis and Distribution of the Auxin Efflux Carrier PIN2 Require Vacuolar NHX-Type Cation/H⁺ Antiporter Activity.

ABSTRACT: The Arabidopsis vacuolar Na⁺/H⁺ transporters (NHXs) are important regulators of intracellular pH, Na⁺ and K⁺ homeostasis and necessary for normal plant growth, development, and stress acclimation. Arabidopsis contains four vacuolar NHX isoforms known as AtNHX1 to AtNHX4. The quadruple knockout nhx1nhx2nhx3nhx4, lacking any vacuolar NHX-type antiporter activity, displayed auxin-related phenotypes including loss of apical dominance, reduced root growth, impaired gravitropism and less sensitivity to exogenous IAA and NAA, but not to 2,4-D. In nhx1nhx2nhx3nhx4, the abundance of the auxin efflux carrier PIN2, but not PIN1, was drastically reduced at the plasma membrane and was concomitant with an increase in PIN2 labeled in

SUBMITTER: Zhang S 

PROVIDER: S-EPMC7601841 | biostudies-literature | 2020 Oct

REPOSITORIES: biostudies-literature