Synthetic hormone gets the better of pathogen which causes potato disease

Researchers at the University of Groningen and Wageningen University have succeeded in synthesizing the mating hormone of the plant pathogen which causes potato disease, Phytopthora. The synthetic hormone initiates the production of sexual spores in the same way the natural hormone does. According to the research team, the findings can be used in the fight against potato disease. The results of the study are being published in the Proceedings of the National Academy of Sciences (PNAS) this week.

Every year, the potato disease Phytopthora causes significant losses in the potato harvest, leading farmers to spray potato plants with herbicides at least once every week. Tomato plants, too, can fall victim to Phytopthora.

The only known sexual hormone in Phytopthora (Alfa 1) appears in sixteen different chemical manifestations. The hormone causes the micro-organism to form sexual spores. The research team has now constructed two substances in the laboratory resembling the natural hormone. Although the chemical construction of the synthetic hormone differs from that of the natural hormone, the synthetic hormone causes a nearly identical biological reaction in the fungus-type micro-organism. The greater the quantity of synthetic hormone administered, the greater the effect. The spores prove to be viable and are able to germinate.

The development of the synthesized hormone makes it possible to broaden the scope of research into the pathogen Phytopthora. The sexual volatiles found can be produced in large quantities, enabling experiments not just in a test tube, but also with real plants.

Sexual reproduction is of vital importance to Phytopthora. During sexual reproduction, the parental strains exchange genetic information, leading to a greater genetic variety in the offspring. With every change in the environment, new varieties of the pathogen surface which are more resistant to new conditions and thus prevent the disease from becoming extinct. This is why Phytopthora is able to survive fairly easily, despite intensive efforts to eradicate the pathogen with herbicides.

More information

Tim den Hartog, University of Groningen, + 31 50 363 4252, e-mail: t.den.hartog@rug.nl or

Prof. Ben Feringa, tel. + 31 50 363 4235