Expression profiles of five FT-like genes and functional analysis of PhFT-1 in a Phalaenopsis hybrid

ABSTRACT

Background: Phalaenopsis is an important ornamental flowering plant that belongs to the Orchidaceae family and is cultivated worldwide. Phalaenopsis has a long juvenile phase; therefore, it is important to understand the genetic elements regulating the transition from vegetative phase to reproductive phase. In this study, FLOWERING LOCUS T (FT) homologs in Phalaenopsis were cloned, and their effects on flowering were analyzed. Results: A total of five FT-like genes were identified in Phalaenopsis. Phylogenetic and expression analyses of these five FT-like genes indicated that some of these genes might participate in the regulation of flowering. A novel FT-like gene, PhFT-1, distantly related to previously reported FT genes in Arabidopsis and other dicot crops, was also found to be a positive regulator of flowering as heterologous expression of PhFT-1 in Arabidopsis causes an early flowering phenotype. Conclusions: Five FT homologous genes from Phalaenopsis orchid were identified, and PhFT-1 positively regulates flowering.