Rosaceae is a large family, however, our understanding of its phylogeny is based largely on morphological observations. To understand the relationship between subfamilies Rosoideae, Amygdaloideae, Maloideae and Spiraeoideae at a molecular level, we isolated and compared the plant phosphatidyl ethanolamine-binding protein-like genes TERMINAL FLOWER1 (TFL1)-like and CENTRORADIALIS (CEN)-like, which are involved in the control of shoot meristem identity and flowering time. A comparison of gene structures and phylogenetic tree analyses by the Neighbor-Joining method showed that each of the two TFL1-like (MdTFL1-1 and MdTFL1-2) and CEN-like genes (MdCENa and MdCENb) in Maloideae were classified into two distinct clades. The TFL1-like and CEN-like genes of Gillenia in Spiraeoideae belonged to monophyletic Maloideae groups, suggesting that Gillenia and Maloideae have a common near ancestor. However, the Gillenia TFL1-like gene does not contain the insertion sequence of the third intron that is found in MdTFL1-2-like genes of the members of Maloideae such as apple, Korean whitebeam, quince, and Siberian mountain ash. Therefore, after the Maloideae ancestor genome became polyploid through hybridization between Gillenia-like species or genome doubling, an insertion sequence of the third intron of MdTFL1-2-like genes was generated.
Apple MdMADS13 has a transcription factor with MADS domain. Moreover, it is expressed specifically at petals and carpels. The product forms a dimer with MdPISTILLATA (MdPI) protein as a class B gene for floral organ formation. Reportedly, in parthenocarpic cultivars of apple (Spencer Seedless, Wellington Bloomless, Wickson and Noblow) the MdPI function is lost by genome insertion of retrotransposon, which cultivars show a homeotic mutation of floral organs, petals to sepals and stamens to carpels. Apple fruit is pome from receptacle tissue, and MdSEPALLATA (MdMADS8/9) and AGAMOUS homologues MdMADS15/22 involved in the fruit development, the transgenic apple suppressed these gene showed poor fruit development and abnormal flower formation. This article describes that the MdMADS13 retained expression after blossom and small fruits of parthenocarpic cultivars. Yeast two-hybrid experiment showed specific binding between MdPI and MdMADS13 proteins. Furthermore, transgenic Arabidopsis with 35S::MdMADS13 have malformed stamens and carpels. These results suggest strongly that MdMADS13 is related to flower organ formation as a class B gene with MdPI.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.