Rainer Hedrich: Can plants feel?
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- Rainer Hedrich, Professor of Botany at the Julius von Sachs Institute of Biosciences of the University of Würzburg. Quelle: privat
22.09.2010 -
Do plants have feelings? Briefly put, this could serve as an outline of Rainer Hedrich’s research interests. The biologist examines electric phenomena in plants at his professorship at the University of Würzburg. Human nerve cells conduct signals such as heat, cold, or injury by means of electrical signals. Plants do the same, only much, much slower. Hedrich has now been granted European Research funding to study the most responsive plants of all: The Venus Fly Trap
The story of Hedrich’s entry into the world of research is closely tied to his academic teacher, the biophysicist Erwin Neher. In 1991, Neher was awarded the Nobel Prize for his work on the clarification of the function of ion channels in humans. These channels allow stimuli to be conducted as electrical impulses from cell to cell. At the time, Hedrich was active in the Nobel Laureate’s laboratory at the Max Planck Institute for Plants in Göttingen, and was the first researcher to demonstrate ion channels in plants. “A really amazing moment,” recalls the biologist, “back then, no one would have thought that plants also have ion channels.” He has since remained loyal to his field of research, and with no loss of enthusiasm. Hedrich’s working group has been involved in a significant number of important research findings. Just last year, the team of scientists succeeded in clarifying the mode of functionality of the stomata found on the underside of leaves, and learnt more about the tricks employed by plants to save water.
Lightning-fast reactions
Today, Hedrich's laboratory at the University of Würzburg is a world reference laboratory for the investigation of electrical phenomena in plants, including nutrient uptake and storage, and motional processes. Much like in humans, the dissemination of information functions via electrical impulses. If plant cells are stimulated, positively charged ions surge into the cells through so-called ion channels, or, conversely, negatively charged anions are disseminated. An electrical impulse – referred to as depolarisation – is created over the envelope membrane of the cell by this shift in charge distribution. In this way, signals are passed from cell to cell. In humans, this process takes five to ten milliseconds; in plants, however, it can take minutes. By comparison, Hedrich’s current study object, the Venus Fly Trap, is lightning quick. The nerve impulses of the plant reach the intended location within seconds.
Faster than its victims
“The Venus Fly Trap has developed a trap system that can react more quickly than any other plant,” says Hedrich. This requires a sophisticated mechanism. The two inside leaves of the carnivorous plant are covered with tactile hairs. If an insect touches the hair enough times to indicate that it is a living object, the trap snaps shut. This process takes just a tenth of a second, making it one of the fastest known movements in the plant kingdom. “Even Darwin took an interest in the Venus Fly Trap in 1873,” says Hedrich. The electrical excitation of plants had already been noticed at the time, but apart from a small number of further investigations in the 1970s, the research area has remained quiet. Until recently, the appropriate technology for root cause analysis was simply not available. “With the development of high-resolution biophysical techniques and the advent of molecular biology, this has now changed,” says Hedrich. The scientist is extremely enthusiastic when speaking of his studies into the insect-eating plant. “It’s like a rediscovered old love.”
The European Research Council is supporting Hedrich’s ‘relationship work’ with 2.5 million euros. This will above all be used to explore the touch and taste senses of the plant. Among other activities, the researchers in Würzburg will analyse the genetic material of the most important types of traps, in order to find genes that are active only in this mechanism. Through comparisons with other plant species, and also from a perspective that takes into account the plants’ prey, they hope to shed some light on the evolution of this special diet. “This could also help in the understanding of the evolution of primitive nervous systems, and possibly even of our own” says Hedrich.
A researcher teaching research
The 53 year-old is not just a passionate researcher, but also an ardent interpreter of science. Working alongside a colleague, he has established a fully functional research laboratory for students in a neighbouring school, where until recently research into carnivorous plants was also being carried out. Moreover, a series of films about the area of ion channels has been created under his guidance. The sophisticated science films will be shown in schools, and in the context of university biology studies. The latest episode will cover his current research object. But before Hedrich steps in front of the camera, there remains more work to do to decipher the secret life of the 'green carnivore’.
Autorin: Ute Zauft
