Figure 6.

TET8 mediates GIPC transport and affects exosome/EV biogenesis. In WT plants, sorting and trafficking of GIPCs are mediated in a TET8-dependent manner (with assistance of γ2-COPI) or in a TET8-independent manner. MVBs with enough GIPC-enriched ILVs prefer to fuse with the PM and release vesicles as EVs. In GIPC-deficient plants (such as IPUT1-RNAi in WT), the MVBs fuse less frequently with the PM, resulting in a decrease of EVs. In the tet8 mutant, GIPC accumulation is blocked, leading to impaired secretion of EVs. The red dotted lines represent the TET8-independent pathway. The red lines point to the TET8-dependent pathway. The black dotted lines are unknown pathways that mediate MVB fusion to the PM or vacuoles. CW, cell wall; EVs, extracellular vesicles; GIPCs, glycosyl inositol phosphoceramides; MVBs, multivesicular bodies; PD, plasmodesmata; PM, plasma membrane.