Connecting the Dots

December 13, 2016

New faculty member Ya Yang uses plant specimens and computation to find unusual connections between plants.

Ya Yang

What do sugar beets and cacti have in common?

Ya Yang, an assistant professor in the Department of Plant and Microbial Biology (PMB), asked the question while conducting plant evolutionary studies as a postdoc at the University of Michigan, Ann Arbor. She was looking for connections among plants that share interesting biological phenomena, such as similar pigments and carnivory. Using novel data filtering and analysis she developed, Yang was able to cross-reference hundreds of plant species when she found that sugar beets and cacti are related by evolutionary history and their pigmentation. She says plant specimens and computer programming are primary tools in her area of research: plant systematics and evolutionary genomics.

“Plant systematics is a way of understanding how plants relate to each other, and how we classify and name them,” explained Yang. “It’s broader than just taxonomy and uses statistical methods and models to reconstruct the relationships of plants, how they branch from each other and when. We can reconstruct historical events and build a tree to illustrate how things changed over time.”

Several years ago, Yang began reconstructing relationships in a group of plants called Euphorbia, a large, complex and  poorly understood genus. Euphorbias emerged from the tropics and evolved over 60 million years to thrive in desert climates. Yang wants to learn how they changed so radically and believes the key may lie in how they process sunlight.

“I’m looking at both DNA and RNA to understand plants’ photosynthesis strategies. We can look at RNA not only to reconstruct the history from its sequence but it can also tell us what the plant was doing at the time of its death,” Yang says. 

Connecting the dots between beets and cacti was an accident. Twenty-first century computer science — and ready access to big data — now enable scientists to process information like never before. Where older methods let scientists examine only one gene at time, current programs are able to look at 15,000 genes at once. “We used to be limited by the amount of available sequences. Now we have so much that the key is how we interpret such large datasets,” says Yang.

Yang, who is also the curator of the University of Minnesota Herbarium, says she’s excited about generating more data and continuing to look for correlations between chemistry and the genes underlying it. She anticipates teaching the general botany course in 2018 and is looking forward to volume 12 of Flora of North America, “a comprehensive taxonomic guide to the extraordinary diversity of plant life covering our continent north of Mexico,” to which she contributed 16 taxa.

“I’m really excited to carry out multidisciplinary research on cool plants and collaborate with other researches at CBS and the University of Minnesota,” says Yang.  —Monique Dubos