A breakthrough in understanding how flowers form, is reported by scientists at the Max Planck Institute for Developmental Biology in Tuebingen, Germany, and the John Innes Centre in Norwich, UK. In an article published in the international journal "Science", they show how a small molecule that is made in leaves is able to induce the formation of flowers at the growing tip of a plant. Because flowers in turn make fruits and seeds, including cereal grains, this new knowledge could have important applications in crop plants (Science, August 12, 2005).

The blossoms of cherry trees are celebrated in many places including the Jefferson Memorial in Washington, DC, or Ueno Park in Tokyo, Japan, because they tell us that spring has finally arrived. As we all know, most plants make flowers only at certain times of the year, the spring blooms of cherry trees being but one example. Plants can use several cues from the environment to choose the season that is right for flowering. For example, some plants such as tulips will not flower unless exposed for several months to winter cold, while others rely on the increase in day length that heralds the arrival of spring.

Scientists have known since the 1930s that plants detect day length with their leaves. Since flowers form typically at the tip of branches, researchers concluded that a signal that induces flowering must travel from the leaves to the site where flowers are initiated. Despite these early findings, little progress has been made in pinpointing the hypothetical flower-inducing substance, dubbed florigen. These difficulties have led many scientists to believe that florigen might be not a single entity, but a complex mixture of molecules. In the new work, two teams, led by Detlef Weigel at the Max Planck Institute in Tuebingen and Philip Wigge at the John Innes Centre, have n
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Contact: Detlef Weigel
weigel@weigelworld.org
49-7071-601-1410
Max-Planck-Gesellschaft
17-Aug-2005