October 6, 2004

Cornellian Uncovers Secret of Flowers

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When Brian Ayre came to Cornell in 1998 to complete postdoctoral research in Robert Turgeon’s plant science laboratory, he never imagined he would stumble onto what he calls, “the Holy Grail of Botany.” Yet that is exactly what Ayre did while working with Turgeon, a Cornell plant science professor and Ayre’s postdoctoral adviser.

The “Holy Grail” that Ayre may have uncovered is the longtime mystery of plant flowering. For years, plant flowering had been credited to “florigen,” a chemical signal that was believed to be the key to this process. “Nobody identified what [florigen] was and it took on mythical proportions,” Ayre explained.

“[Florigen] is a longstanding problem,” Turgeon echoed. “It’s a classical, unsolved problem.”

Ayre’s research, published jointly with Turgeon in the August edition of Plant Physiology, may have changed all of that. In it, Ayre, currently an assistant professor at the University of North Texas, describes how the protein CONSTANS plays a vital role in plant flowering.

Whether CONSTANS is actually the mysterious “florigen” remains unclear. “It’s possible it is florigen itself,” Turgeon said, “but we weren’t able to prove that.”

“If you look at [plant flowering] as a series of steps, we have identified [CONSTANS] as a very clear part of that series,” Ayre added.

The discovery of CONSTANS’ role in flowering happened while Ayre was researching plant phloem physiology and transport and began hearing about new research being produced at other universities.

“There were a lot of papers coming out in other universities about proteins moving through the phloem,” Ayre said. “I thought, being in the Turgeon lab, I was in a very good position to do a couple experiments and start looking at possible mechanisms in the way floral stimulation may move through the leaves to the growth tip,” he explained.

Using a galactinol synthase promoter developed by Turgeon, Ayre started experimenting. “I suggested to [Brian] we could use [the promoter] to follow the transport of proteins,” Turgeon remembered. “It was Brian who came up with the idea of trying CONSTANS as a specific protein to use. All of a sudden, [things] took off.”

According to Ayre, his research has received “a good bit of attention” since its August publication, but he relayed that the true impact will not necessarily be seen for years. “The citation record is ultimately how we judge ourselves,” he explained, “and we don’t know [the impact] yet, but in a couple of years we should have a good idea.”

Prof. Emeritus Jan Zeevaart, plant biology, Michigan State University, and a leading florigen researcher, seemed encouraged by the findings. “It is gratifying to see there are finally molecular approaches to the problem,” said Zeevaart.

“For quite some time, some people have ridiculed the concept of florigen, but those of us who have worked on the physiological aspects always knew that it could not be dismissed so easily.”

Beyond the potentially weighty contributions to the field of plant science, the findings could have a significant impact on the day-to-day life of the average person.

“With this technology, it’s a way to control or manipulate the timing of the gene,” Ayre said. If CONSTANS can be controlled, then it follows that there is a strong possibility that flowering can also be controlled.

“Controlling flowering could be very important to agriculture,” Turgeon expanded. Essentially, the new knowledge could give farmers the option to control when their crops bloom. Ayre explained that this could be useful in a more northern climate like Canada, where access to sunlight is more erratic and farmers usually have more trouble consistently growing crops.

Ayre credits Cornell for helping to foster and encourage his curiosity and passion for research and experimentation. “It was a great atmosphere [at Cornell],” Ayre said. “It was the intellectually stimulating environment at Cornell that made the work possible.” Ayre also credited the faculty he worked with, complimenting some of the “old timers” who have been perplexed by the “florigen” mystery for years and who were very supportive of him throughout.

Despite the agricultural and economic potentialities of his and Turgeon’s research and findings, Ayre is quick to point out that neither of those were motivating factors. Instead, he explained that his work had much more to do with uncovering the “basic science” of plant flowering. In potentially unlocking the plant science “Holy Grail,” Ayre wants people to remember that “the pursuit of pure science is really why we did this.”

Archived article by Billy McAleer
Sun Staff Writer