Flower Power

Scientists have uncovered a protein in plant leaves that causes plants to flower. Changes in day length drive the flowering process.

“This could be a really important breakthrough in plant science,” said study team member Colin Turnbull from the Imperial College London. “Since the 1930s when it first became clear that something was communicating the perception of changes in day length in leaves to the shoot apex, and causing flowering, scientists have been trying to work out exactly how this mechanism works.”

A gene called Flowering Locus T (FT gene) produces the so-called FT protein in a plant’s leaves. The scientists found this protein travels through the plant’s vascular system from the leaf to the shoot apex, where it activates other genes, causing the plant to flower.

The researchers tracked the traveling protein by tagging it with a green fluorescent protein originally isolated from jellyfish. They grafted two Arabidopsis plants together, only one of which contained the gene for the fluorescent version of FT. This allowed them to show conclusively that FT protein moved from where it was produced in the leaves of one plant, across into the other plant.

“Now that we have been able to track FT protein moving from its source in leaves to its destination in the shoot tip, we have a plausible explanation for how plants respond to day length,” Turnbull explained.

The discovery could have practical implications as well. “The ability to control flowering is of enormous commercial significance across food and non-food species, for example extending production seasons or designing plants better adapted to changing climate,” Turnbull said.

—LiveScience Staff

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Credit: David Flagg/National Science Foundation