M3.4: Intraspecific signals in parasitic plants

Thomas Spallek & Yuelin Zhang

Mass occurrences of parasitic plants are most problematic in agricultural settings and have been observed for witchweeds such as Striga hermonthica and Striga gesnerioides. Non-weedy species, such as the European yellow rattle, Rhinanthus alectorolophus, also grow in patches where the parasite reaches high densities and maximizes its growth-reducing effect on the host plant community (figure, left panel). The IRTG project M3.4 aims to quantify potential intraspecific signals (figure middle panel) and their consequences for the physiology of parasitic plants to better understand mass occurrences of parasitic plants.



For this, we will analyze if and which metabolites in the exudates of parasitic plants act as intraspecific signals. We will mainly work on the root parasite Phtheirospermum japonicum, but also test if other related parasitic plants produce and sense similar metabolites. To identify these unknown metabolites, we will work together with the IRTG partner labs headed by Prof. Feussner at the University of Göttingen and Prof. Yuelin Zhang from UBC Vancouver. Both groups have extensively contributed to the identification and characterization of plant metabolites with signaling capacity in the past. In parallel, we will conduct forward genetic screening of a Phtheirospermum japonicum mutant population to identify the underlying signaling and biosynthesis pathways required for sensing and producing intraspecific signals in parasitic plants (figure, right panel).

References:

Spallek, T., Mutuku, M., and Shirasu, K. (2013). The genus Striga: a witch profile. Mol. Plant Pathol. 14: 861–9.