Skip to main content Skip to navigation

Seeds of knowledge: Researchers explore genetic secrets of plant growth


Michael Neff holds a tray of experimental cress plants
Professor Michael Neff holds experimental cress plants, part of his team’s fundamental research into key growth hormones called brassinosteroids.

Her only tools a wooden toothpick and her own steady hands, Shelby Westenskow maneuvers a reddish-brown seed, smaller than a grain of sand, into place on a circular dish of clear, sticky gel.

“It’s getting down to basics — just me, a toothpick, and a seed,” said Westenskow, a doctoral student researcher in the Department of Crop and Soil Sciences at Washington State University.

Most of her fellow student researchers think this is dull work, but Westenskow sees value in the patient task of planting thousands of tiny cress plant seeds.

Headphones on, sterile air blowing into her face from the silvery grille of the clean bench in front of her, Westenskow settles into a rhythm: Dip, poke, plate.

“I can see I’m doing it perfectly,” she said.

In this case, perfection means that Westenskow and her fellow student researchers, led and mentored by Professor Michael Neff, can see exactly how these seedlings develop. Most of them are mutants, bred for a specific purpose: To shed light on how genes influence the way plants grow.

Cress seeds manipulated by a toothpick.
Mutant cress seeds, sorted by student Shelby Westenskow, may hold the key to understanding genes behind important growth hormones.

Plants that tell a story

In a nearby greenhouse, Michael Neff is making plants miserable. And he couldn’t be more thrilled.

“I’m really excited about what’s going on here,” says Neff, a scientist in the Department of Crop and Soil Sciences, as he spots a golden-colored, full-grown cress plant that stands out from its neighbors.

Molecular geneticists like him are always on the lookout for something called a phenotype: A physical example of how plants and animals express their genes.

“We’ve got some beautiful phenotypes here,” says Neff, examining the plant’s curly leaves and wrinkled, bumpy seeds. It’s taller than its neighbors by a third, and has already flowered, days before its typical cousins.

“We now have a change in growth and development that we can see for ourselves,” Neff said. “That change means we can tell a story.”

Working with a team of students at WSU and collaborators overseas, and funded by a $465,000 grant from the National Science Foundation, Neff is exploring the fundamental ways that genes influence special growth-promoting plant hormones, called brassinosteroids.

“Nearly every plant uses these hormones to grow,” explains Neff. “Plants have evolved many ways to keep these hormones at exactly the right level at precisely the right time. Too much, and they grow too fast. Too little, they never grow at all.”

In plants, as in all living things, genes are the code that tells the plants when and how to use hormones.

In the case of brassinosteroids, genes from a half-dozen different gene families involving things like seed development, root development and disease resistance, combine to ensure the hormone is at the right level.

“Plants have this tremendous redundancy built in,” Neff said. “That tells us this hormone must be extremely important.”

In the greenhouse, Neff is growing mutant plants whose genes give them too much growth hormone. The cress plant with funny-looking leaves is a prime example of one with too much steroids, which Neff and his students have created by knocking out genes that control the compounds that degrade the hormone.

“We’re trying to find the sweet spot,” he says — the right mix of genes that allow plants to grow taller, but avoid getting sick. The answer could transform agriculture as well as human health.

Impact on crops, medicine

Neff, who once quit college to work as a dishwasher and lab clerk in an AIDS-fighting virus lab before returning for his PhD, has always done fundamental research with real-world impacts in mind.

Today, his team of undergraduates, graduate students and one high schooler are gaining hands-on research experience as they explore the genes that make plants do what we want them to: grow big and strong, give us food and fight disease.

“Say you’re growing biofuels,” Neff said. “You may want a plant that grows taller, faster. If you’re trying to optimize crops for smaller farms, you may want a plant whose leaves grow taller and straighter. Understanding how these genes are regulated could get us there.”

Beyond that, plant hormones are very similar to ones in our own bodies.

“Our understanding could have an impact on how living things, from plants to people, perceive hormones during development,” says Neff, “which could lead to unexpected discoveries in human health.”

“Fundamental research can have game-changing impacts,” he added. “Discoveries we make today could end up being used in ways we never imagined.”