2.A.7.4.5
UMAMIT14 amino acid efflux transporter of 374 aas and 10 TMSs, a member of the nodulin MtN21 family. It is involved in phloem unloading in Arabidopsis roots (Besnard et al. 2016). UMAMIT14 is expressed in root pericycle and phloem cells and mediates export of a broad range of amino acids. Loss-of-function of UMAMIT14 leads to a reduced shoot-to-root and root-to-medium transfer of amino acids originating from the leaves. These fluxes were further reduced in an umamti14 umamit18 double loss-of-function mutant. Thus, UMAMIT14 is involved in phloem unloading of amino acids in roots, and both UMAMIT14 and UMAMIT18 are involved in the radial transport of amino acids in roots (Besnard et al. 2016).