Features
A Good Time to Blossom
Grad student's project may help create more beautiful blossoms and help feed the world
BY ANDREW VOWLES
Can plants count? That's one of the intriguing ideas under study by a Guelph graduate student who hopes to answer another key question: How do plants know when it's time to bloom?
Learning more about flowering processes may benefit green thumbs like her botanist parents, but it might also help feed the world, says Viktoriya Coneva, a master's student in the Department of Molecular and Cellular Biology (MCB). If growers better understand those processes, they may be able to improve production of food crops such as wheat, rice and corn, which are staples for ever-growing human populations.
Those growers would probably marry long-standing breeding methods with the kinds of genetic and molecular tools used by Coneva in and around the science complex lab of her supervisor, Prof. Joe Colasanti. They're studying chemical and molecular signals that drive development in plants and especially what sparks those growing plants to bloom.
Her project begins not in the lab but upstairs in the controlled-access phytotron, the signature greenhouse on the top floor of the science complex, where she tends a cluster of corn plants.
Surveying the young plants, she says: “We know surprisingly little about how flowering is accomplished in this crop.”
Learn how it works, she says, and we might be able to alter genes and proteins and encourage plants to bloom to measure.
The Guelph researchers are studying individual genes involved in flowering. Their work was described in a paper published last fall in the Journal of Experimental Botany; Coneva was lead author. Two years ago, she co-authored an article in BMC Genomics.
They've linked flowering genes with genes controlling photosynthesis, allowing plants to make food. But the picture is more complicated, with flowering time depending on a variety of factors.
How much light is the plant getting? What particular wavelengths of light? How is the plant sensing changing day length? Scientists know that many plants have to go through a cold period before they'll bloom. What's the role of chemical substances in the plant, including metabolites and hormones?
Coneva is studying the novel idea that the plant “counts” its own leaves, waiting until reaching a magic number before triggering blooming. She believes the “brain” lies in the plant's meristem — its collection of stem cells that drive growth and development.
The meristem receives protein signals sent back through the plant from its leaves. Reaching a threshold amount of protein may kick the plant into flowering mode.
She studies plants with normal or mutant forms of the maize indeterminate gene, thought to act as a regulator on other plant genes involved in development.
Using electron microscopy, she is also studying structural differences in plant cell walls. More cellulose in certain plants may slow the molecular signals and delay flowering, she explains.
Similar mechanisms probably work in various kinds of plants, but Coneva stresses that other factors may affect different species. It's partly that complexity that drew her to the field in the first place.
As a senior undergraduate at Guelph, she had pursued a different molecular biology project in Colasanti's lab. That's when she found herself intrigued by the basic but crucial developmental questions he was asking — questions that echoed the kinds of ideas she'd already considered as the daughter of a botanist couple.
She and her family came to Canada from Bulgaria in 2000 when Coneva was 17. Both parents had earned doctorates in horticulture from Plovdiv Agricultural University. Her dad, Rumen, was a research associate at U of G's Vineland campus and now studies ornamental plant breeding at Virginia Polytechnic Institute. Her mom, Elina, did a post-doc in fruit crops at Vineland before becoming a professor at Auburn University in Alabama.
Viktoriya Coneva may have inherited her academic interests from her parents but not necessarily their green thumbs. Those corn plants in the greenhouse are thriving, but she admits that her few houseplants at home could be faring better.
Still, they're fascinating things, she says. “How do they know to flower at the right time? There are so many questions, and when there are more questions than answers, that's when I find it exciting.”
Pointing to his student's curiosity and tenacity, Colasanti says Coneva has “made major contributions to the lab and the field in general. Her 2007 paper, the first reported molecular profile comparing flowering and non-flowering maize, should keep us busy for years analyzing the gene differences she found.”