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Dandelions manipulated to have compound leaves showed irregular leaf form and did not flower.

Manipulated Organism: Dandelion (Taraxacum officinale Web.).

Inserted Transgenes: hooded gene (bkn3, barley knox3) derived from barley. This gene is in the group of knox1 homeobox genes that have been found to be involved in the formation of compound leaves in other plants. The gene was fused to the cauliflower mosaic virus (CaMV-35S) promoter so that the gene would be expressed in all parts of the plant.

Goal: Induce dandelion plants to make compound (divided) leaves instead of simple, lobed leaves as it normally does.

Intended Effect: Transgenic plants expressing the transgene did form compound leaves.

Unintended Effects:
  • The compound leaves were highly irregular in form.
  • Meristematic (embryonic tissue) areas were present on the leaves and in some cases developed into rosettes. In other words, little plantlets grew out of the leaves.
  • The transgenic plants did not flower.

Source: Müller, K., X. He, R. Fischer, and D. Prüfer (2006). "Constitutive knox1 Gene Expression in Dandelion (Taraxacum officinale, Web.) Changes Leaf Morphology from Simple to Compound," Planta vol. 224, pp. 1023-7.

Author Affiliations: Fraunhofer Institute for Molecular Biology and Applied Ecology, Aachen, Germany; Institute for Biochemistry and Biotechnology of Plants, Westfälische Wilhelms-Universität, Münster, Germany; Department of Plant Molecular and Developmental Biology, Peking University, China.

Funding: Not reported.

Product Status: Basic research; not for product development.

Copyright 2008 The Nature Institute.

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