The discovery and use of antibiotics to fight against bacterial infection have let to overrun many diseases. However overuse and/or incorrect use of the antibiotics increase the concentration of these compounds in the environment and create the selective pressure, which promotes antibiotic resistant microorganisms. Multidrug resistant pathogenic bacteria are a huge problem of the modern medical science because of the infections, which they cause, are almost incurable.

Polar auxin transport is essential for normal plant growth and development. Auxin moves between plant cells through a combination of membrane diffusion and carrier-mediated transport. Recent studies have identified several classes of membrane proteins involved in auxin transport, and have started to uncover a system that regulates auxin flux through plant tissues via the subcellular asymmetric locali- zation of these proteins.