Bioinformatics Group, Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany; Bioinformatics and Mathematical Modeling Department, Centre for Plant Systems Biology and Biotechnology, Plovdiv, Bulgaria; Systems Biology and Mathematical Modeling Group, Max Planck Institute of Molecular Plant Physiology, Potsdam, Germany. Bioinformatics Group, Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany; Bioinformatics and Mathematical Modeling Department, Centre for Plant Systems Biology and Biotechnology, Plovdiv, Bulgaria; Systems Biology and Mathematical Modeling Group, Max Planck Institute of Molecular Plant Physiology, Potsdam, Germany. Electronic address: nikoloski@mpimp-golm.mpg.de.