Mediates the export of free fatty acid from the plastids. Potentially prefers palmitic acid (C16:0) over oleic acid (C18:1) and stearic acid (C18:0). Not involved in fatty acid activation. Required for biogenesis of the outer pollen cell wall, in particular for the assembly of exine and pollen coat and for the release of ketone wax components. Expressed in cotyledons, leaves, sepals and pollen. Expressed at all developmental stages, with a peak at early pollen development. Up-regulated upon induction of early leaf senescence. Reduced biomass and male sterility. Reduced size, thinner inflorescence stalks and flowers producing short siliques containing almost no seeds. Small vascular bundles with reduced secondary cell walls and modified cuticular wax composition with strongly reduced content in C29-ketone wax components. For all TMEM14 proteins, 4 hydrophobic alpha-helical domains are predicted. However, NMR structure determination of the human TMEM14A showed that only 3 of these helices are membrane-spaning while the amphiphilic N-terminal helix is probably located at the lipid micelle-water interface. Belongs to the TMEM14 family.