1. Institute of Biochemistry and Biology, Mass Spectrometry of Biopolymers, University of Potsdam, Karl‐Liebknecht‐Str. 24‐25, Building 20, D‐14476 Potsdam‐Golm, Germany
2. Department of Plant Physiology, Institute of Biochemistry and Biology, University of Potsdam, Karl‐Liebknecht‐Str. 24‐25, Building 20, D‐14476 Potsdam‐Golm, Germany
3. Akita Prefectural University, Akita, Japan