How does the Christmas cactus know to blossom each December? Why do dandelions mock homeowners with yellow flags of victory during the lush lawn season? Just how do plants know when to bloom?
Instructions for being a timely bloomer are coded in a plant’s genetics, or DNA. Environmental cues, such as day length, temperature and rainfall, trigger this genetic alarm clock, spurring the plant to take action. Complicating our understanding of this process, plant species have individualized genetic programs, and, they often change their settings depending on their native climate.
To understand the mechanisms underlying the genetics of timekeeping, a team of FIBR researchers will study the genome, or entire genetic code, of Arabidopsis thaliana, commonly known as “thale cress” or “mouse-ear cress.” This well-characterized member of the mustard family was the first plant to have its genome deciphered providing biologists with a solid starting point to understand the genetics of the plant kingdom.
Led by Brown University researchers, an international team of molecular biologists, evolutionary geneticists, ecologists, plant specialists and computer scientists will test the natural responses of a core set of inbred Arabidopsis lines that originated from the Mediterranean to subarctic climates. They will then determine the responses of these same plants when transplanted to six sites in Spain, Germany, England and Finland. The results will help scientists understand how organisms assess a complex set of signals and respond appropriately, and how genetically programmed responses adapt to environmental changes.
The molecular, genetic and ecological data collected will test their prediction that different climates and locations favor some flowering responses over others. Moreover, genetic mapping methods—similar to those used to identify genes contributing to human disease—will test whether genetic differences contribute to different flowering responses. The team will also develop computer models to predict how identified genetic differences affect a plant’s underlying biochemistry and its ability to adapt to diverse geographic regions or climate change.
Antioch Dunes Evening Primrose
Credit: Ivette Loredo, U.S. Fish and Wildlife Service
Another team of FIBR scientists is also looking at Arabidopsis, but at the cellular level. Led by a University of California researcher, this group is mapping changes to each individual cell in a plant’s meristem—its growth center—as it forms a new leaf or flower. By merging the latest and greatest in biotechnology, mathematical modeling and computer visualization, the team will create a plant in silico, or virtual plant, to model real data collected using fluorescent proteins marking specific cells in bioengineered plants. The virtual plant will allow researchers to track cell-by-cell changes during plant growth and development as well as predict altered growth patterns in various environmental conditions.
"Earth laughs in flowers...." Ralph Waldo Emerson