Four TFL1/CEN-like genes on distinct linkage groups show different expression patterns to regulate vegetative and reproductive development in apple (Malus x domestica Borkh.)

• Published in: Plant and cell physiology Vol. 50; no. 2; pp. 394 - 412
• Main Authors: Mimida, N.(National Inst. of Fruit Tree Science, Morioka (Japan)), Kotoda, N, Ueda, T, Igarashi, M, Hatsuyama, Y, Iwanami, H, Moriya, S, Abe, K
• Format: Journal Article
• Language: English
• Published: Japan Oxford University Press 01-02-2009; Oxford Publishing Limited (England)
• Subjects: Amino Acid Sequence; Apple; ARABIDOPSIS; Arabidopsis - genetics; Arabidopsis - growth & development; Arabidopsis Proteins - genetics; Arabidopsis Proteins - physiology; CENTRORADIALIS (CEN); Chromosome Mapping; Cloning, Molecular; DNA, Plant - genetics; ETAPAS DE DESARROLLO DE LA PLANTA; EXPRESION GENICA; EXPRESSION DES GENES; FLOWER1; Flowering time; Flowers - genetics; Flowers - growth & development; GENE; GENE EXPRESSION; Gene Expression Regulation, Plant; Gene family; GENES; Genes, Plant; MALUS; Malus - genetics; Malus - growth & development; Malus×domestica Borkh; Meristem - genetics; Meristem - growth & development; Molecular Sequence Data; Multigene Family; ORGANE REPRODUCTEUR VEGETAL; ORGANE VEGETATIF DES PLANTES; ORGANOS REPRODUCTORES VEGETALES; ORGANOS VEGETATIVOS DE LAS PLANTAS; PLANT DEVELOPMENTAL STAGES; Plant Proteins - genetics; Plant Proteins - physiology; PLANT REPRODUCTIVE ORGANS; PLANT VEGETATIVE ORGANS; PLANTAS TRANSGENICAS; PLANTE TRANSGENIQUE; Plants, Genetically Modified - genetics; Plants, Genetically Modified - growth & development; Sequence Alignment; Sequence Analysis, DNA; STADE DE DEVELOPPEMENT VEGETAL; TERMINAL; TFL1; TRANSGENIC PLANTS; (; ); Apple; Gene family; Flowering time; ×
• ISSN: 0032-0781; 1471-9053
• DOI: 10.1093/pcp/pcp001

Recent molecular analyses in several plant species revealed that TERMINAL FLOWER1 (TFL1) and CENTRORADIALIS (CEN) homologs are involved in regulating the flowering time and/or maintaining the inflorescence meristem. In apple (Malus×domestica Borkh.), four TFL1/CEN-like genes, MdTFL1, MdTFL1a, MdCENa and MdCENb, were found and mapped by a similar position on putatively homoeologous linkage groups. Apple TFL1/CEN-like genes functioned equivalently to TFL1 when expressed constitutively in transgenic Arabidopsis plants, suggesting that they have a potential to complement the TFL1 function. Because MdTFL1 and MdTFL1a were expressed in the vegetative tissues in both the adult and juvenile phases, they could function redundantly as a flowering repressor and a regulator of vegetative meristem identity. On the other hand, MdCENa was mainly expressed in fruit receptacles, cultured tissues and roots, suggesting that it is involved in the development of proliferating tissues but not in the control of the transition from the juvenile to the adult phase. In contrast, MdCENb was silenced in most organs probably due to gene duplication by the polyploid origin of apple. The expression patterns of MdTFL1 and MdCENa in apple were also supported by the heterologous expression of β-glucuronidase fused with their promoter regions in transgenic Arabidopsis. Our results suggest that functional divergence of the roles in the regulation of vegetative meristem identity may have occurred among four TFL1/CEN-like genes during evolution in apple.