Plant Biotic Interactions

The ability to extract nutrients and water from other plants evolved at least twelve times independently and gave rise to more than 4700 parasitic plant species (1). One family of root parasites, the Orobanchaceae, is with more than 2100 species, one of the species-riches lineages of parasitic plants. Most Orobanchaceae species are hemiparasitic, meaning they obtain water and nutrients from the host but maintain the ability to fix carbons by photosynthesis. Some genera, such as Striga, are obligate parasites, requiring a connection to the host shortly after germinating. Other species, like Phtheirospermum japonicum, can also live without a host (2).

Some Striga species prefer hosts that are important food crops such as sorghum, maize, rice, and cowpeas. For this reason, Striga is a major biological constraint of cereal production in Sub-Saharan Africa (3, 4). In our research, we use non-weedy Phtheirospermum plants as a model system to study parasitism at a molecular level. Finding genes and processes that control parasitism in the Orobanchaceae family may help to protect crops from parasitic weeds.

Our group focuses on isolating mutants with traits related to parasitism and identifying the causative mutation by whole-genome sequencing. To further characterize identified genes, we visualize gene expression in parasites with fluorescent reporters, knock out genes by CRISPR/Cas9 and characterize proteins and metabolites in-vitro to learn how parasitic plants interact with their host, other parasites, and the environment (5).

References:
(1) Nickrent (2020) doi: https://doi.org/10.1002/tax.12195
(2) Spallek et al. (2017): https://doi.org/10.1073/pnas.1619078114
(3) Spallek et al. (2013): https://doi.org/10.1111/mpp.12058
(4) UN World Food Programme: https://innovation.wfp.org/project/toothpick
(5) Greifenhagen et al. (2021): https://doi.org/10.1111/nph.17615