Diterpene Triggers Fungal Reproduction

The diterpene shown has been identified as a mating hormone used by members of the fungal plant pathogen family Phytophthora to regulate their sexual reproduction (Science 2005, 309, 1828). Members of this family of pathogens were responsible for the potato blight that caused the Irish potato famine in the 1840s as well as for recent outbreaks of sudden oak death, a disease that's devastated forests in the U.S. and Europe. The identification of this hormone may offer a target for new strategies to control the reproduction of these fungi, says Makoto Ojika of Nagoya University, in Japan. Phytophthora have two mating types, A1 and A2. Both can produce male and female organs, but fertilization occurs only when given the go-ahead by a hormone secreted by the opposite type. Ojika's team purified and chemically characterized such a hormone from a model Phytophthora species. The A1-secreted diterpene coaxes A2 female organs to develop into sexual spores in this and a number of other Phytophthora species, they report.