Answers to these fundamental questions can come from an unusual group of flowering plants: parasites of the genus Cuscuta (dodder).
Cuscuta spec. (yellow) spiralling around a host plant stem (green).
Several unique features enable parasitic plants to infect other plants and live heterotrophically from what these hosts provide. The most amazing phenomenon was the development of feeding organs that connect parasite and host physically and physiologically.
A Cuscuta reflexa suction cup (top) attaching firmly to a host stem (bottom). The cone-shaped feeding organ which protrudes from the middle of the suction cup and grows into the the host is invisible in this view. B The cone-shaped feeding organ visualized by light microscopy after cross-sectioning an infection site. The parasitic tissue is highlighted in yellow. C Despite their close entanglement (right) can parasite and host tissue be distinguished using fluorescence labelled antibodies (left).
The technical term, “haustorium”, that is derived from the latin “haurire” which means “to drink”, reflects its main function well. This cone-shaped organ essentially fulfills a similar function as roots do in other plants. For this they establish intimate cellular connections to the host tissue. The ability of Cuscuta to manipulate cells of plants from unrelated taxa across wide parts of the plant kingdom into forming open cellular connections with the haustorial surface cells is one of the fundamental aspects of plant biology that is still poorly understood. The “TFS-Enigma” project will focus on this enigmatic phenomenon and will close this important gap. During the project, we will develop knowledge and methodology related to the analysis of the host-parasite interface.