Polar auxin transport

Polar auxin transport pathway of Arabidopsis. Even though we have shown a representative diagram of influx and efflux proteins on different but adjacent cells, the auxin influx and efflux transport proteins when present in the same cell, are often located in the plasma membrane of cell's opposite side or on the sides (left/right). All the different paralogs of influx and efflux proteins may not be present in the same cell. Often their expression and localization is tissue, cell, organ and development stage specific. This helps in directing the flow of auxin towards 'auxin maxima' sites in plant organs and cells as needed. In some cases auxin can permeate through the plasma membrane. The Arabidopsis gene products PIN5, PIN6 and PIN8 were removed from the pathway since they are known to be involved in intracellular auxin transport rather than the intercellular auxin transport.

拟南芥的极性生长素运输途径。尽管我们已经展示了不同但相邻细胞中内流和外流蛋白的代表图，但当内流和外流蛋白存在于同一细胞中时，它们通常位于细胞相对侧的质膜或两侧（左侧/右侧）。并非所有内流和外流蛋白的不同同源物都存在于同一细胞中。它们的表达和定位往往具有组织、细胞、器官和发育阶段特异性。这有助于引导生长素流向植物器官和细胞中的‘生长素极值’位置，以满足需要。在某些情况下，生长素可以穿透质膜。由于PIN5、PIN6和PIN8基因产物已知参与细胞内生长素运输而非细胞间生长素运输，因此已从途径中移除。