The transfer of indole-3-acetic acid (IAA) between both IAA synthesizing compartments of the cell – cytoplasm and chloroplast (influx into chloroplasts from cytoplasm and efflux from chloroplasts into cytoplasm) was educed by employing model systems. From the obtained results the presumption on IAA interaction with proteins IAA-transporters another than pin-formed (PINs) or auxin permease (AUX1) in chloroplast membrane was formulated. The suggestion on the possibility of IAA metabolism occurring in this cell compartment was done. The possible role of IAA and auxin-binding proteins (ABPs) complexes formed in chloroplast was discussed.
Keywords: chloroplast, IAA, auxin-binding proteins (ABPs), IAA-ABP complexes.