Isolation of LEAFY and TERMINAL FLOWER 1 homologues from six fruit tree species in the subfamily Maloideae of the Rosaceae

Abstract

Flowering is an essential stage of fruit production. To understand the molecular mechanisms controlling flowering in maloid fruit tree species, we isolated and analyzed genes homologous to Arabidopsis LEAFY (LFY; flower meristem identity gene) and TERMINAL FLOWER 1 (TFL1; inflorescence meristem identity gene) from six fruit tree species in the subfamily Maloideae of the Rosaceae; apple (Malus · domestica), Japanese pear (Pyrus pyrifolia), European pear (Pyrus communis), quince (Cydonia oblonga), Chinese quince (Chaenomeles sinensis), and loquat (Eriobotrya japonica). Two LFY homologues and two TFL1 homologues were cloned from all six maloid species by rapid amplification of 3¢ and 5¢ cDNA ends, reverse transcription-PCR, and PCR with genomic DNA. Phylogenetic analysis by the neighbor-joining method showed that the two LFY homologues and two TFL1 homologues were classified into two distinct clades. The presence of multiple copies of LFY and TFL1 homologues is discussed with reference to the polyploid origin of the subfamily Maloideae.

Relationship between Floral Development and Transcription Levels of LEAFY and TERMINAL FLOWER 1 Homologs in Japanese Pear (Pyrus pyrifolia Nakai) and Quince (Cydonia oblonga Mill.)

“…2.0 software (Applied Biosystems) based on previously isolated cDNA sequences of maloid LFY and TFL1 homologs (Table 1). In our previous research, we isolated two different types of LFY and TFL1 homologs both from Japanese pear and quince (Esumi et al, 2005). Thus, we designed the primer sets from the conserved regions of the two different LFY and TFL1 homologs, respectively to investigate the sum of the transcripts of two different homologs.…”

“…Equal amounts of the two PpLFY-2 antisense probes were mixed and used for hybridization. Since cDNA sequences of PpLFY-1 (AB162029), PpLFY-2, CoLFY-1 (AB162031), and CoLFY-2 (AB162037) are highly conserved (Esumi et al, 2005), the PpLFY-2 antisense probe cross-hybridized to all four of the LFY homologs. Similarly, the PpTFL1-1 antisense probe hybridized to PpTFL1-1, PpTFL1-2 (AB162047), CoTFL1-1 (AB162043), and CoTFL1-2 (AB162049).…”

“…(Boss et al, 2001(Boss et al, , 2006Calonje et al, 2004;Carmona et al, 2002;Jeong et al, 1999;Joly et al, 2004;Kotoda et al, 2000Kotoda et al, , 2002Kotoda and Wada, 2005;Pillitteri et al, 2004;Sung et al, 1999Sung et al, , 2000Wada et al, 2002;Walton et al, 2001). We previously isolated and compared LFY and TFL1 homologs from six maloid fruit trees, including Japanese pear and quince, to elucidate the molecular basis of the differences in inflorescence architecture (Esumi et al, 2005); however, the derived amino acid sequences differed only slightly in their primary structures.…”

Expression Analysis of the LFY and TFL1 Homologs in Floral Buds of Japanese Pear (Pyrus pyrifolia Nakai) and Quince (Cydonia oblonga Mill.)

“…Similarly, LFY and TFL1 homologs in quince were named CoLFY-1 (Cydonia oblonga LFY-1) (AB162031) and CoLFY-2 (AB162037), and CoTFL1-1 (AB162043) and CoTFL1-2 (AB162049), respectively. Each pair of LFY and TFL1 homologs shared greater than 90% identity (Esumi et al, 2005). Given the high percentage of identity between each homologous pair, we previously investigated the spatial and temporal expression patterns of LFY or TFL1 homologs as a whole (Esumi et al, 2007).…”

Effects of the plant growth regulators on expression of MdTFL1 promoter fused β-glucuronidase (GUS) reporter gene in apple (Malus spp.) tissues in vitro

“…It is noteworthy that molecular evidence have clarified the transition process from vegetative to reproductive phase in the apical bud. Among these studies, two apple flowering genes, the TERMINAL FLOWER1 orthologs (plant phosphatidyl ethanolamine-binding protein homologs) MdTFL1-1 (MdTFL1) and MdTFL1-2 (MdTFL1a), have been isolated and characterized (Esumi et al 2005;Kotoda et al 2005Kotoda et al , 2006Mimida et al 2009Mimida et al , 2011. The temporal and spatial expression patterns of MdTFL1-1 and MdTFL1-2 are similar, and both are strongly expressed in the rib meristem zone of the shoot apex throughout the vegetative phase in adult plants.…”