15th International Conference on Arabidopsis Research - TAIR

T01-103
Components of the Arabidopsis autonomous floral
promotion pathway, FCA and FY, are conserved in
grasses
Somrutai Winichayakul(1), Nicola Beswick(1), Gregory Bryan(2) and Richard
Macknight(1)
1-Department of Biochemistry, University of Otago, PO Box 56, Dunedin, New Zealand
2-AgResearch Grasslands, Palmerston North, New Zealand
Flowering time is an important trait agriculturally. To investigate if the same
genetic pathways that control the flowering time of the model dicot Arabidopsis
are also present in monocots, two components of the Arabidopsis
autonomous floral promotion pathway, FCA and FY, were isolated from rice
(Oryza sativa) and ryegrass (Lolium perenne). The predicted FCA proteins are
highly conserved over the RNA-binding and WW protein interaction domains.
In Arabidopsis, FCA limits its own production by promoting the polyadenylation
of FCA pre-mRNA within intron 3 to form a truncated transcript called
FCA-b. FCA-b transcripts were found in rice and ryegrass. A comparison
of Arabidopsis, rice and ryegrass intron 3 sequences, as well as ESTs
representing FCA-b transcripts from a range of plants, revealed the presence
of conserved sequence that may be required for FCA autoregulation. FCA’s
autoregulation and flowering time functions require FCA to interacts with the
3’ end-processing factor, FY. FY was identified from rice and ryegrass and
encodes proteins with highly conserved WD repeats and a less well-conserved
C-terminal region containing Pro-Pro-Leu-Pro (PPLP) motifs. The FCA
WW domain, which is thought to recognise PPLP motifs, interacted with
ryegrass FY protein in GST-pulldown assays. These experiments suggest that
the FCA and FY genes from monocots may have similar functions to the dicot
flowering-time genes.
T01 Development 1 (Flower, Fertilization, Fruit, Seed)
15 th <strong>International</strong> <strong>Conference</strong> on Arabidopsis Research 2004 · Berlin