The pollen grains of maize, rice and all other cereals, need to store starch as energy deposit for later use during fertilization. A research team, led by Dr. Ivan Acosta from the Max Planck Institute for Plant Breeding Research in Cologne, Germany, together with colleagues from the Umeå Plant Science Centre, Sweden, the Max Planck Institute of Molecular Plant Physiology, Germany and Rutgers University, U.S. now identified the phytohormone auxin as a main driver for energy production during pollen maturation in barley.