Julius Sachs v Praze - anotace přednášky



Prof. Dieter Volkmann



Central Europe, early centre of excellence in plant biology (1850 - 1900).

In the second half of the 19th century, one of the most productive phases of plant biology came to flowering. This colourful bouquet is distinguished by the names of three famous scientists: Julius Sachs, his pupil and assistant Wilhelm Pfeffer, both of whom became fathers of modern plant physiology, and Eduard Strasburger who founded modern plant cell biology. In particular, Sachs developed experimental equipment, mostly rather simple but very effective; e.g. thermostat, clinostat and the root box (Wurzelkasten), through which he was able to create and develop the area of sensory and developmental physiology. Already two of his very early articles, in 1857, when he was working as docent for plant physiology in Prague, are related to plant movements – the light-oriented movements of plants and the periodic leaf movements of Phaseolus. Finally, in the 1890s, a few years before his death, he published his famous series “Physiologische Notizen”, e.g. about mechano- and automorphoses, indicating that growth is a prerequisite for plant responses to environmental factors and for plant morphoses. At that time he used already the term ‘stimulus response chain’ (Reizkette).

Wilhelm Pfeffer was the first botanist who documented plant movements by time lapse movies and the used of a horizontal microscope. He also improved the clinostat, originally developed by Sachs, for investigations of plant responses to gravity, and finally he developed the famous osmometer (Membranosmometer). By this “cell”, later on called “Pfeffersche Zelle”, he estimated quantitatively the osmotic pressure of solutions, indicated the semi-permeability of the plasma membrane, and thereby put plant physiology on an exact chemical and physical basis; the specific area of membrane physiology was born. On the basis of Pfeffer’s knowledge, van’t Hoff obtained the first Nobel Prize for chemistry in 1901.

On the other hand, Strasburger in cooperation with the physicist Ernst Abbe, contributed by his microscopic work on plant anatomy, to the final establishment of Cell Theory. He described in detail the processes of karyo- and cytokinesis and their independence, their stages and even the exact timecourse of mitosis and cell plate formation, as well as considering centripetal versus centrifugal formation of cell walls in algae and land plants. His observations on pollen tube growth and fertilization are even today of importance.

These three excellent scientists were highly effective, successful and renowned. They were also three highly individual and divergent characters. Nevertheless, they held several features in common. All were passionate scientists, strong personalities attracting students and scientists from all over the world - Sachs and Pfeffer mainly from Japan, Strasburger from the US. They rejected several offers of positions in famous universities in central Europe in preference for spending more than thirty years in research and teaching at their beloved universities in Wűrzburg (Sachs), Leipzig (Pfeffer) and Bonn (Strasburger).

Professor Dieter Volkmann (*1941 Červená Voda), studies of mathematics, physics, chemistry, biology, philosophy, theology in Würzburg, Tübingen and Bonn. Exams for High School teaching (Gymnasium) in mathematics, biology and philosophy; PhD (Dr. rer. nat.) in Bonn: geotropism; Habilitation in Bonn: membrane differentiation; 20 years professor in Bonn: plant cell biology, plant signaling and communication.

http://scholar.google.com/citations?user=iRVCGogAAAAJ&hl=de
http://www.plantbehavior.org/who.html
http://www.arriam.spb.ru/eng/lab9/partners.html