Polar auxin transport (PAT) is a process that controls all stages of plant growth and development . Knowing responsible for this process mechanisms thus became one of the main goals of modern science . With the latest research using molecular biology techniques were able to confirm wagered decades earlier hypothesis chemioosmotyczną . According to the PAT is achieved by the presence in the cytoplasmic membrane of specialized carriers entering (AUX) and leaving (PIN) from the cell auxin . Are currently known families of genes encoding said carriers .