Artificial hormone tricks potato pathoge

17 Jun 2008 Unit: Wageningen University Number: P040 Researchers from the University of Groningen and Wageningen University have succeeded in artificially imitating sex hormones from  the pathogen  Phytophthora, which causes potato blight. The synthetic hormone initiates the production of oospores in the same way as the natural hormone. This discovery can be used in the battle against potato blight, wrote the research team in this week's issue of the Proceedings of the National Academy of Sciences (PNAS). The potato pathogen Phytophthora causes major losses every year to potato crops. For this reason, farmers spray the potato plants at least every week with chemical agents. Tomato plants can also be affected by Phytophthora. The only known sex hormone in Phytophthora (Alpha 1) has 16 different chemical forms. The hormones cause the microorganism to form sexual spores (oospores). The research team has now constructed two related substances in the laboratory. Although the chemical structure of the artificial hormones deviates from the natural hormone, they are capable of causing virtually the same biological reaction in the fungus-like microorganism. The effect increases as more artificial hormone is used. The spores that are formed are viable and can germinate. The synthesis of the artificial hormone makes it possible to research the pathogen Phytophthora in greater depth. The volatile hormones that have been discovered can be manufactured in large quantities, so that experiments can be conducted on real plants and not only in test tubes. Sexual reproduction is crucial for the survival of Phytophthora. During sexual reproduction, the 'parent strains' exchange genetic information, creating a large genetic variation in the progeny. During every change in the environment, there are always a few variants that are better adapted to the new conditions and in this way prevent the organism from becoming extinct. As a result, Phytophthora can survive relatively easily despite intensive chemical control. Note to the editor For more information, please contact ir. Klaas Bouwmeester (Wageningen University), tel: 0317 483403, Prof. dr. ir. Francine Govers, Wageningen University, tel: 0317 483138 or Prof. dr. Ben Feringa, University of Groningen, tel: 050 363 4235

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