Every spring, gardeners
That cotton shirt you’re wearing? It came from seeds. The meat on your plate and the wool in your rug? Seeds played a big part in their creation. The petunias spilling from your window box, the maple tree shading your patio, the oil you use to sauté your onions, and yes, your onions, too—all from seeds.
Often overlooked and seldom given its proper due, the seed has nonetheless enticed an interdisciplinary group of renowned University of Kentucky scientists to band together into the Seed Biology Group. Bruce Downie, associate professor in horticulture and the current group leader, explains part of the fascination.
“Every packet has a little miracle inside it,” he said. “It’s been recognized for eons that as a civilization we are heavily dependent on seeds, but we just don’t understand much about them.”Bruce Downie
Critical RoleDennis TeKrony founded the group in the early 1990s. He and Dennis Egli have been faculty members in the plant and soil sciences department for nearly 40 years. The two men—TeKrony, a seed scientist, and Egli, a soybean physiologist—found common ground in seed germination and vigor testing, with Egli also studying yield physiology.
Their applied research in agronomics is especially important because an estimated 70 percent of the world’s food supply comes from seeds such as corn, wheat, soybeans, and rice. That doesn’t even include the animals we eat, which consume either seeds or forages that spring from seeds.
Apart from feeding the masses, seeds are also the major propagation tool used by plant breeders developing new cultivars.
“To me, seeds are really critical,” TeKrony said. “I’ll admit for many years many people thought, ‘This seed will germinate. We don’t have to worry about it.’ ” He laughed at the notion. “It was like we had more important things to do. And as a result we have plant breeding and crop physiologists probably at every land grant university, but we don’t have a seed program at each one. I think there are some of us who recognize that there are a lot of things we don’t really know about seed. And that’s where seed science and technology areas developed to provide training specifically in those areas.”
UK a Leader
UK is one of the few land grant universities with a seed biology program. During the last decade, more master’s and doctoral candidates have graduated from the program than any school in the country. UK graduates have found good career opportunities in the seed industry and universities around the world.
“We are in a very strong position,” said TeKrony, who recently retired but continues to teach an online course in seed vigor on a post-retirement basis. “I know we talk about being top 20. I feel like our group is top five right now.”
Bruce Downie, without hesitation, puts the program at number one. His enthusiasm over the magnitude of the group’s research is contagious.
“This is the foundation of agriculture. Every other endeavor within an agricultural effort goes to protecting the crop, and the crop, 99 percent of the time, is seeds,” he said. “So it’s amazing that we put as much effort into understanding other aspects of plant physiology and growth and are still so woefully ignorant of seed development.”
A Seed Knows
Look beneath the surface, zoom into the microscopic mechanisms that make a seed tick, into DNA and beyond, and that’s where you’ll find Downie’s world and that of colleague Sharyn Perry, a molecular biologist in the plant and soil sciences department.
Perry explores how the plant embryo forms. She works with a protein that regulates developmental programs during embryo formation. She describes the cell’s programming by using the analogy of eye and liver cells in the human body. Though the DNA is the same, the information is used differently. Some genes are turned on, others are turned off, and the result is an eye or a liver.
Sharyn Perry, left, and graduate student Yumei Zheng
Downie jokes about piggybacking on Perry’s research, because he focuses on the “back end of development”—when the mother plant breaks its connection to the seed, allowing the seed to undergo some profound physiological changes.
The process protects the seeds against extreme stress. Downie illustrates its effectiveness by describing seeds plunged into liquid nitrogen at a temperature of minus 196 degrees Celsius. Miraculously, the seeds survive.
“How can this happen?” he wonders. “What physiological mechanisms are put in place to allow the cells to withstand that type of insult? There’s just a raft of information that somehow the embryo can sense and, if you will be anthropomorphic, make a decision as to whether it should go or not. How? Why?”
Sh-h-h . . .
Carol Baskin has a soft, gentle voice, so it’s not exactly surprising to learn that her research, and that of her husband Jerry, focuses on seed dormancy. Dormancy is the period in a seed’s life when it “sleeps,” awaiting the right environmental signals to begin germination. Jerry is a professor in the biology department, and Carol holds a joint professorship in the biology and plant and soil sciences departments. They are both internationally acclaimed ecologists whose research into the dormancy of native species also encompasses biogeography (the distribution of organisms on the earth) as well as the evolutionary relationship between plants. Their work in unlocking the mysteries of dormancy plays a key role in the restoration and preservation of endangered or rare plant species.
They work closely with fellow group member Robert Geneve, a horticulture professor, sharing graduate students and insights and publishing papers together.
Geneve’s basic and applied studies include seed biology, germination, and dormancy. Lately, because of Kentucky’s transition away from tobacco, he is focusing on new crop opportunities, studying the seed biology of an older cultivar of euonymus to try to understand the plant’s invasive properties. This work will help him determine whether a newer, nearly fruitless cultivar is noninvasive and would make a viable horticultural crop.
A Broader Perspective
The Seed Biology Group’s diversity is unusual within academia. Its strength is the willingness of its members to share their knowledge with each other and their students.
“It’s broadened my perspective,” said Egli. “A lot of yield physiologists wouldn’t even think about the seed. They just think about how much we’re producing from the leaves. But actually, the seed controls its own rate of growth. So the fact that the seed has something to do with its growth gives a whole new way of looking at the production of yield and answers a number of questions about how the plant operates.”
That “whole new way of looking” helps graduate students as well. Cindy Finneseth works with seeds five days a week as seed testing coordinator with UK Regulatory Services. She’s also a doctoral candidate, working with Geneve on gamagrass, a native species with potential as a biomass crop for energy production and as a forage crop for livestock. When it comes to unraveling gamagrass dormancy, Finneseth benefits from the expertise available within the group.
“These scientists are world renowned,” she said. “Access to them is great because they’re willing to take the time to answer questions. They make me think about seeds from different perspectives.”
It’s that “different perspective” that has placed UK seed scientists at the top of their fields. Every spring, gardeners and farmers alike take for granted that tiny vibrant plants will faithfully appear from the seeds they sow. At the University of Kentucky, the complex seed systems behind this miracle are gradually being deciphered by the scientists in the Seed Biology Group.
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