Research pinpoints region of plant genome where rising CO2 controls flowering time

Mon, 02/11/2013

LAWRENCE — Henry David Thoreau obsessively recorded the flowering time of plants around Concord, Mass., in the 1850s, while Japanese naturalists took keen note of the flowering time of cherry blossom trees for centuries before that. For hundreds of years, naturalists and scientists have tracked flowering time, because it marks the transition between vegetative and reproductive growth, and it is highly influenced by climate change.

“The timing of when flowering is induced is incredibly important to the reproductive success of any plant,” said Joy Ward, associate professor of ecology and evolutionary biology at the University of Kansas. “If it occurs too early, then not enough resources may be accumulated to maximize reproduction. If it occurs too late, then plants may not have finished or even started producing seeds before the growing season ends. So this timing is absolutely critical.”

Today, in response to climate change, many plant species seem to be flowering earlier than in the past — and scientists have assumed this was due to increasing global temperatures. But Ward’s recent research has shown that higher concentrations of carbon dioxide (CO2) in the atmosphere might play a direct role in influencing flowering times, and this may be as large or larger than the warming effect.

Now, Ward and colleague John Kelly, professor of ecology and evolutionary biology, have pinpointed the region of a plant’s genome that drives changes in flowering time in response to atmospheric levels of CO2 — a breakthrough finding that shows the genetic architecture behind changes in flowering time in response to CO2 in Arabidopsis thaliana, a model species whose genome has been completely sequenced.

“It’s a model system for understanding how other plants respond to the environment,” Ward said. “We now know from a large survey study (published in New Phytologist) that I did that carbon dioxide has large effects on flowering time. My lab identified a specific gene whose expression was effected by carbon dioxide, and we were the first lab to identify genes in the flowering pathways whose expression was sensitive to carbon dioxide.”

To build on that work, Ward and Kelly wanted to understand at the DNA level what areas of the genome might be driving a plant’s response to carbon dioxide for flowering. They cross-bred two parental plant species and let the progeny self-replicate, then genotyped those offspring to determine the location in the genome that controls changes in flowering time in response to rising atmospheric CO2.

“We now know in the whole genome where the gene or genes may be located that are causing a shift in flowering time as related to CO2,” Ward said.

The esteemed and open-access journal PLOS ONE recently published the KU researchers’ findings. Prior to this work, little was known about the “underlying genetic architecture that controls flowering time in response to CO2 at the genomic level, which may impact both wild and crop species.”

Ward said that such basic science could lead to more successful agriculture in ahigh CO2 world of the future, as is predicted by her work and that of other scientists.

“Rising CO2 is occurring across the planet,” Ward said. “So this work is highly relevant to changes in flowering time across all ecosystems. It has the potential to improve crops responses to a changing environment, and to help us better prepare for change. In addition, CO2 is an under-appreciated environmental factor that influences flowering time. We have heard a lot of studies mention that temperature affects flowering time, but carbon dioxide, which plants use as a carbon source for photosynthesis, also drives flowering time even when temperatures are not changed in controlled experiments. It’s key that we understand such changes now through basic research and experimentation, before they start occurring in reality in our crop and natural systems.”

The National Science Foundation funded Ward’s research.

 



Matt Menzenski, a graduate student in Slavic languages & literatures, took this photo during President Obama’s speech at KU Thursday. Menzenski says he was struck by how relaxed the president was in his delivery. He missed a chance to hear former President Bill Clinton speak in his hometown in 2004, but finally got to see a sitting president this week at KU. “The opportunity to hear the president speak is just one of many great opportunities I've had at KU. So many interesting talks and events happen here all the time. I try to attend at least one a week-- it's never hard to find something interesting to go to.” Tags: University of Kansas College of Liberal Arts and Sciences KU School of Languages, Literatures & Cultures KU Dept of Slavic Languages - Friends & Alumni Barack Obama The White House #exploreKU #POTUSatKU

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Explore KU: The Bells of Mount Oread KU’s Campanile, a 120-foot-tall timepiece that tolls automatically on the hour and quarter-hour, not only sounded in the 2015 New Year at midnight with 12 mighty gongs, but also regularly rings up memories for many Jayhawks – the 277 faculty and students who gave their lives during World War II, the graduates who walk through its doors at commencement, and aspiring students who have strolled through the Lawrence campus. (See http://bit.ly/1xjjwJj). For nearly 60 years, KU’s 53-bell carillon has been tolling the sounds of peace and serenity across Mount Oread since it was installed in June 1955 inside the landmark World War II Memorial Campanile, which was dedicated in 1951. (See http://bit.ly/1BoL9jv) The carillon is also a four-octave musical instrument, which is played with a giant keyboard and foot pedals. University Carillonneur Elizabeth Egber-Berghout (http://bit.ly/14fiBPl), associate professor of carillon and organ, climbs 77 steps up a spiral staircase in the bell tower to perform recitals several times a month.


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