Research The Bayer Scientific Magazin, Edition 28
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- Bu səhifədəki naviqasiya:
- Duel with pests makes necessary different strategies and active ingredients
- Analyzing molecular mechanisms and tracking down new targets in insects
Successful team: for Dr. Ralf Nauen, shown here with his colleague Antje Rottmann, research is all about working in the laboratory with an established team while also being able to engage in dialog with scientists all over the world. Dr. Ralf Nauen PORTRAIT Bayer research 28 July 2015 21
research, we also benefit from the experience and tremendous intellectual capital in the department,” says doctoral student Marion Zaworra. The development of such outstanding know-how at Bayer CropScience is also to Nauen’s credit. He began his training as a biology lab technician at Bayer in 1981 and then worked in the field of insect biochemistry. “An early collaboration with a doctoral student inspired me to pursue a scientific career, which my supervisors and Bayer both supported,” Nauen recalls. For his doctoral thesis he studied insects and how they absorb, metabo- lize and eliminate certain active ingredients. “Most of them break down insecticides in the digestive system and neutralize them there. The longer this process takes, the better for the efficacy of the product,” he explains. However, some insects have a natural talent for metabolizing the active ingredients very rapidly. They survive the insecticidal attack and continue to reproduce. After several years, virtually the entire pest species becomes resistant. “That can only be pre- Duel with pests makes necessary different strategies and active ingredients Always on the go: as a resistance manager, Dr. Ralf Nauen not only studies scientific literature (photo above), but also conducts research in the lab together with his doctoral students Denise Steinbach and Marion Zaworra (photo right, left to right). In 2013, he was given the Fellowship Award by the Entomological Society of America (photo below, right). Nauen enjoys getting back to nature by going hiking (photo below, left). vented by using mixed strategies, in other words varying prod- ucts and confronting the pests with different active ingredients,” Nauen says. Random mutations are another cause of resistances, such as the dreaded target site mutation, where a molecular change occurs in the target structure – i.e. the site where the insecticide docks – in just one insect in a billion. The substance can no longer take effect, the pest survives and multiplies. “Mu- tations of this kind are difficult to predict and can take decades to become established,” explains Nauen, who today works in Re- search & Development in Product and Project Support/Life Cycle Management, part of the Pest Control department. There Nauen supervises resistance management, precisely what he aimed for 30 years ago. “I am just as fascinated by my work today as I was back then. The only difference is that the research questions have changed and the responsibility has increased,” he says. And the challenge also has its rewards: for example, Nauen is a fellow of the Royal Entomological Society in London and the Entomolog- ical Society of America, and in 2014, the Bayer expert received the International Award for Research in Agrochemicals from the American Chemical Society, one of the world’s largest and most influential research associations. Nauen was also president of the Insecticide Resistance Action Committee for five years, lon- 22 Bayer research 28 July 2015 Analyzing molecular mechanisms and tracking down new targets in insects ger than anyone else before him. One of the most important achievements for Nauen and his team involves the tiny pollen beetle whose likeness hangs in his office, and which can cause widespread devastation. “This beetle developed alarming resis- tances to all known insecticides. It destroyed entire oilseed rape crops in 2006 and 2007,” Nauen remembers. The problem was that all the insecticides used belonged to the same substance class, the pyrethroids, and had a sim- ilar mode of action. Naturally resistant beetles multiplied for decades unimpeded and the insecticides became ineffective. Nauen’s team analyzed the resistant beetles and tracked down the molecular mechanism protecting them. Based on these find- ings, they worked with government authorities to develop new control strategies. “It is important to recognize and minimize the risk of resistance development at an early stage,” Nauen explains, “because insects that produce several generations a year can develop resistance in a very short time due to the corresponding selection pressure.” But Nauen and his team face other challenges as well: for ex- ample, the process governments use to approve new insecticides is becoming increasingly strict. One important requirement, for instance, is that insecticides must spare bees, which can likewise suffer from the effects of an insecticide if it is used incorrectly. “We therefore study what distinguishes bees from other insects on a molecular level,” Nauen explains. “For example, which de- toxification mechanisms enable them to tolerate certain active ingredients and which genes are responsible for these mecha- nisms.” In collaboration with other colleagues, he wants to find out which target structures the active ingredients must attack to avoid harming beneficial insects. “Then we can subject crop protection substances to much better tests to determine if they are safe for bees, and design modern insecticides to have a more targeted effect,” says Nauen, defining his goal. “Research is a never-ending process. To me, that means research is all about teamwork,” he concludes. www.research.bayer.com/ portrait-nauen More information on this topic Teaming up to combat pests: Dr. Ralf Nauen (4th left) is researching new strategies with his colleagues Harald Köhler, Bettina Lueke, Dr. Cristina Manjon, Ángel David Popa Báez, Denise Steinbach, Marion Zaworra and Antje Rottmann (left to right). Survival artists: bees
Dr. Ralf Nauen PORTRAIT Bayer research 28 July 2015 23
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