Lipid transfer protein that, together with LTPG1, binds to lipids and functions as a component of the cuticular lipid export machinery that performs extensive export of intracellular lipids (e.g. C29 alkane) from epidermal cells to the surface to build the cuticular wax layer and silique walls (PubMed:22891199). Contributes to pre-invasive defense against some non-host powdery mildew pathogens by preventing the penetration of the epidermal cell wall by the fungal agents (e.g. Blumeria graminis f. sp. hordei (Bgh)) (PubMed:30102837). Involved in seed and ovule maturation and development, probably by regulating the fatty acids homeostasis during suberin and sporopollenin biosynthesis or deposition (PubMed:24460633). Targeted to the plasma membrane via the vesicular trafficking system. Up-regulated in the epidermis of top stems. Expressed in roots, cotyledons, seedlings, leaves, stems, buds, flower and silique walls (PubMed:23893219). Preferentially expressed in the shoot apical meristem and the root meristem (PubMed:21558309). Also detected in expanding leaves and petals, developing flowers, and elongating pistils, stamens and siliques (PubMed:21558309). Accumulates in seeds after imbibition (PubMed:23893219). Mainly present in elongating or expanding tissues (PubMed:21558309). Strongly expressed in the aerial portions and root tips of seedlings. Present in stem and leaf epidermis, including the trichomes, leaf mesophyll cells, and stem cortex and xylem. In flowers, observed in the upper portion of the styles, anther filament, and veins of the sepals and petals, silique walls and developing seeds (PubMed:23893219). O-glycosylated on hydroxyprolines; noncontiguous hydroxylproline residues are glycosylated with arabinogalactan. Reduced cuticular wax load on the stem surface and in silique walls, with altered cuticular lipid composition (especially C29 alkane) associated with diffuse cuticular layer structure (PubMed:22891199). Increased susceptibility to penetration of the epidermal cell wall by the non-host mildew fungal agent Blumeria graminis f. sp. hordei (Bgh) (PubMed:30102837). Some early aborted seeds and infertile ovules, and increased salt permeability in seeds (PubMed:24460633). Belongs to the plant LTP family.