Cloning and expression analysis of BlFTL in Betula luminifera

Key words: 
• forest tree breeding /
• Betula luminifera /
• BlFTL /
• gene clone /
• gene expression

Abstract: Flowering Locus T （FT） gene plays a crucial role in flower formation of plants. To clarify the function of FT-like genes in Betula luminifera will be helpful to learning about the mechanism of flowering formation in woody plant. The reverse transcription polymerase chain reaction （RT-PCR） and rapid amplification of cDNA ends （RACE） methods were used to clone a Flowering Locus T （FT）-like homolog （named BlFTL） from Betula luminifera （FT）-like）. Sequence analysis with show translations software showed that the full length of BlFTL cDNA was 924 bp and contained a single open reading frame （116-640 bp） encoding a protein of 174 amino acids （GenBank NO. JQ951966）. The BlFTL protein had a typical phosphatidyl ethanolamine-binding protein （PEBP） domain which was an important characterization of the FT family protein. Alignment FT protein sequence in different plants showed that the BlFTL protein shared a 94% similarity with the Ficus carica flowering locus T protein （FcFT）. Also，during flowering in April，the expression of BlFTL in female flowers was almost 50 folds higher than in male flowers. In addition，in normal flowering plants after August，with the formation of the male inflorescence and mixed buds，BlFTL expressed highly in leaves in flowering plants，but no expression in non-flowering plants. In stems，the expression of BlFTL of flowering plants was 6 folds higher than in non-flowering plants. These results inferred that BlFTL was involved in flower formation of Betula luminifera.［Ch，8 fig. 13 ref.］