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New Penn State center focuses on the rule breakers of the plant world

27 July 2020
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dodder covers a field of its host plants
The parasitic plant dodder (yellow) parasitizes a wide range of agriculturally important plants. Credit: Claude dePamphilis

The world’s largest formal group of researchers studying parasitic and carnivorous plants can be found at Penn State, thanks to the new Center for Parasitic and Carnivorous Plants within the Huck Institutes of the Life Sciences. The center, which was formalized in 2019, brings together researchers from across the University, including five from the Eberly College of Science, who use a variety of interdisciplinary techniques to study these curious plants. 

“Parasitic and carnivorous plants are the rule breakers of the plant world,” said Claude dePamphilis, professor of biology and director of the center. “They are extraordinarily interesting organisms that push many of the boundaries that we normally associate with plants. Studying them allows us to understand how we might revise these rules and expand our understandings of how plants really work.”

Many parasitic and carnivorous plants do not have the leaves and roots typically associated with plants and instead have highly specialized structures to siphon off nutrients from other plants or to trap and eat animals. Some have completely lost their ability to photosynthesize, which is usually considered a fundamental characteristic of plants. Parasitic plants have the largest genomes of known plants, and carnivorous plants have the smallest, which poses interesting questions about how these types of plants evolved.

The center’s members study these rule breakers from a variety of perspectives, from the basic biology and molecular and cellular function to the evolution of their unique structures to their interactions with microbes and other animals.

“Everyone in the center brings their own perspective and deep, specialized interest,” said Michael Axtell, professor of biology and a member of the center. “By bringing together such a broad group of collaborators who are open minded enough to look outside the narrow box in which they spend most of their days playing, really cool things can happen.”

While understanding how these extremely unusual plants function and evolve is fascinating from a biological perspective, carnivorous and parasitic plants also have important economic value. For example, many carnivorous plants are popular ornamentals, but others are rare or endangered species.

“The specialized habitats that carnivorous plants live in are especially fragile, being susceptible to effects like pollution,” said Tanya Renner, assistant professor of entomology and a member of the center. “Therefore, the plants themselves can also act as indicators of ecosystem health.” 

Renner is especially interested in the origin, evolution, and regulation of the digestive enzymes that carnivorous plants use to acquire essential nutrients from nonsoil sources, primarily insect prey.

On the other hand, many parasitic plants, like Striga (also known as witchweed) and Cuscuta (also known as dodder), are major agricultural pests. Center member and Assistant Professor of Biology Jesse Lasky studies host adaptations to Striga, which is one of the greatest threats to food security in Africa, while Axtel and dePamphilis study the exchange of genetic material between Cuscuta and its host.

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Kelly and dePamphilis with parasitic plant
The quarantine facility allows Penn State researchers like graduate student Elizabeth Kelly and Claude dePamphilis to study parasitic plants like dodder, pictured here growing on a Coleus plant. Credit: Nate Follmer

To support the study of agriculturally dangerous parasitic plants like Striga and Cuscuta, dePamphilis championed the creation of a quarantine facility at Penn State. With support from multiple colleges and especially the Eberly College of Science and the Department of Biology, the USDA-regulated growth and containment facility opened in 2019. In addition to highly controlled growth- chamber space, the facility contains two sets of automatic, magnetically locking doors, and negative airflow pushing air and any tiny seeds from the parasitic plants back into the room so they cannot escape the lab.

 

“We’ve been growing parasitic plants in our greenhouses for decades now, but now we are able to grow plants like Striga and Orobanche, which are devastating problems in agriculture around the world,” said dePamphilis. “And that’s allowed us to jump-start some new kinds of research that we were unable to do previously.”

The formalization of the center not only fosters interactions across the University but also provides financial support for training and to bring in visiting seminar speakers. The center plans to sponsor workshops that focus on integrative methods to study these plants.

“We also hope the center will provide a good training environment for graduate students and postdoctoral researchers,” said Axtell. “By being exposed to a wide range of research expertise, their training is a little more holistic than it might otherwise be. Just being able to meet regularly and not being siloed in your lab or to the floor of your building can make a big difference in training. You can see things from different perspectives, which could lead to a real breakthrough.”

Other center members include Associate Professor of Biology Charles Anderson, Associate Professor of Biology Tomas Carlo-Joglar, and Assistant Professor of Plant Science Francisco Dini-Andreote.