Molecular cloning of the CaLFY, putative pepper ortholog of FLO/LFY

摘要

The FLO/LFY genes of plants regulate the transition from inflorescence to floral meristem. To isolate the FLO/LFY ortholog in pepper (Capsicum annuum), RT-PCR was performed using primer pairs derived from the conserved sequences of other FLO/LFY orthologs; a partial 948-bp DNA fragment was obtained. A 1,251-bp full coding sequence of the FLO/LFY-like gene homolog was identified after a pepper cDNA library screening and was designated CaLFY. The CaLFY DNA sequence was 3,982 bp long, containing three exons and two introns. CaLFY was predicted to encode a protein sharing 77%, 79%, and 78% identity, respectively, with FA (tomato), NFL1 (tobacco), and ALF (petunia), the FLO/LFY ortholog proteins in Solanaceae. Semiquantitative RT-PCR revealed that CaLFY transcripts were abundantly expressed in floral tissue. Through genetic mapping, CaLFY was placed into the middle of pepper chromosome 3; its location showed close synteny with FA on tomato chromosome 3. Overexpression of CaLFY cDNA under the control of a CaMV 35S promoter in tobacco caused leaf tissue to form at the floral meristem. Moreover, a severe early-flowering phenotype was observed. Taken together, these results indicate that CaLFY is a putative pepper ortholog of FLO/LFY.