Hans Mohr, Honorary Editor of Planta, died on 29 December 2016. He was born in Altburg (Black Forest) on 11 May 1930 and was the first of his family who went to grammar school. He studied physics, biology and philosophy at the University of Tübingen. His teacher Erwin Bünning impressed him and thus Hans Mohr decided to focus on biology. In 1956 Hans Mohr obtained his PhD on action spectroscopy of fern seed germination, which led to his first two publications in Planta. As postdoc of the group of Sterling Hendricks in Beltsville (USA) Hans Mohr continued to study photomorphogenesis. In 1959 Hans Mohr obtained his” habilitation” at the University of Tübingen and was 1960 the youngest Ordinarius—full professor—at the University of Freiburg as the successor of Friedrich Oelkers. In 1992 Hans Mohr became a board member of the Academy of “Technikfolgenabschätzung” in Stuttgart. Hans Mohr retired in 1998 but he continued to be extremely active writing books and scientific manuscripts.

Hans Mohr was a distinguished, very creative whole plant physiologist with a dream of an analytical plant physiology. The main focus of his research was the study of the mechanism of the plant photoreceptors—phytochromes, cryptochromes and the UVB receptor (UVR8). 1966 he hypothesised that the primary function of phytochrome is regulation of gene activity. First, this was highly controversially discussed but it turned out later that the prediction of Hans Mohr was correct. The other main topic of his research was plant development, primary and secondary differentiation. He made ground breaking discoveries in the area of chloroplast development and he focused his investigations on the interactions between light, nitrogen and plastid development.

Hans Mohr served the scientific community in many aspects. He built up the new biology at the University of Freiburg, he initiated the first SFB in Freiburg, he was Vice Rector for research of the university and he was elected as a member of the DFG senate and the presidium of the Alexander von Humboldt foundation. He became a member of the Leopoldina (Deutsche Akademie der Naturforscher Nationale Akademie der Wissenschaften) in 1996 and in 1982 a member of the Heidelberger Akademie der Wissenschaften. He was a President and honorary member of the German Botanical Society and he received honorary doctorates from the Universities of Straßburg (France) and Limburg (Netherlands). He obtained many more honours : Max Born medal for responsibility in science, Bundesverdienstkreuz am Bande (1993) und 1. Klasse (1998), Cothenius medal in gold of the Leopoldina…

Of his many—more than 40 books—he wrote the first “Lehrbuch der Pflanzenphysiologie” 1969 (new later editions with Peter Schopfer have been translated in several languages). The books “Lectures on Photomorphogenesis” (1971) and “Lectures on Structure and Significance of Sciences” (1977) should also be mentioned, because they were written as a result of lectures during his guest professorships at the University of Massachusetts.

Already in 1966 at an age of 36 Hans Mohr became a member of the Editorial Board of Planta. From 1978 till 1982 he was Managing Editor together with Anton Lang and Malcolm B. Wilkins and shortly thereafter he became Honorary Editor of Planta. With Hans Mohr the German plant sciences lost one of their outstanding plant physiologists and Planta lost an extreme correct and engaged editor, and I lost my teacher and wonderful friend.

Prof. Dr Eberhard Schäfer

Freiburg, February 2017