FT-Overexpression Induces Early Flowering and Reproductive Development in Eucalyptus

Eucalyptus trees are one of the most important species for forestry. However, eucalyptus flowering only occurs years after planting, limiting its breeding. To speed flowering, the team of Steve H. Strauss from Oregon State University transformed Eucalyptus grandis × Eucalyptus urophylla hybrids (SP7) using several constructs that allow overexpression of the FLOWERING LOCUS T (FT) gene.

FT overexpression led to very early flowering, with the fastest flowering observed in events containing the Arabidopsis thaliana FT gene (AtFT). Under heat conditions, early flowering was also observed in events with Populus trichocarpa FT1 (PtFT1) controlled by a heat-shock promoter.

Early flowering trees grew robustly, but are highly branched compared to non-flowering transgenic and control trees. AtFT-induced flowers were morphologically normal and also produced viable pollen grains and seeds. Many selfed-seedlings inherited the AtFT gene and flowered early.

FT overexpression-induced flowering in Eucalyptus may be a valuable means of accelerating breeding and genetic studies.

For more information, read the article on Plant Biotechnology Journal.