Expression of FcFT1, a FLOWERING LOCUS T-like gene, is regulated by light and associated with inflorescence differentiation in fig (Ficus caricaL.)

BMC Plant Biology

Research Article

Yoshiaki Inoue¹  Shuichi Himeno¹  Takao Nakahara²  Mitsuo Awamura³  Keita Hirashima³  Chiharu Hirata³  Hidetoshi Ikegami³  Hitoshi Nogata⁴  Hiroshi Yakushiji⁵  Masashi Mori⁶ 

[1] Fukuoka Agricultural Research Center Buzen Station, 2-4-1 Nishiizumi, 824-0038, Yukuhashi, Fukuoka, Japan;Fukuoka Agricultural Research Center Yame Station, 3266-1 Honbun, 834-1213, Kuroki, Yame, Fukuoka, Japan;Fukuoka Agricultural Research Center, 587 Yoshiki, 818-8549, Chikushino, Fukuoka, Japan;Fukuoka Prefectural Control Station for Pests, 423 Yoshiki, 818-0004, Chikushino, Fukuoka, Japan;Grape and Persimmon Research Station, National Institute of Fruit Tree Science, National Agriculture and Food Research Organization, NARO, Akitsu 301-2, Higashi Hiroshima, 739-2494, Hiroshima, Japan;Ishikawa Prefectural University, 921-8836 Suematsu, 834-1213, Nonoichi, Ishikawa, Japan;

关键词: Bearing habit;    Floral differentiation;    Flowering locus T;    Light regulation;   

DOI  :  10.1186/1471-2229-13-216

 received in 2013-10-08, accepted in 2013-12-05,  发布年份 2013

来源: Springer

【 摘 要 】

BackgroundBecause the floral induction occurs in many plants when specific environmental conditions are satisfied, most plants bloom and bear fruit during the same season each year. In fig, by contrast, the time interval during which inflorescence (flower bud, fruit) differentiation occurs corresponds to the shoot elongation period. Fig trees thus differ from many species in their reproductive growth characteristics. To date, however, the molecular mechanisms underlying this unorthodox physiology of floral induction and fruit setting in fig trees have not been elucidated.ResultsWe isolated a FLOWERING LOCUS T (FT)-like gene from fig and examined its function, characteristics, and expression patterns. The isolated gene, F. carica FT (FcFT1), is single copy in fig and shows the highest similarity at the amino acid level (93.1%) to apple MdFT2. We sequenced its upstream region (1,644 bp) and identified many light-responsive elements. FcFT1 was mainly expressed in leaves and induced early flowering in transgenic tobacco, suggesting that FcFT1 is a fig FT ortholog. Real-time reverse-transcription PCR analysis revealed that FcFT1 mRNA expression occurred only in leaves at the lower nodes, the early fruit setting positions. mRNA levels remained a constant for approximately 5 months from spring to autumn, corresponding almost exactly to the inflorescence differentiation season. Diurnal variation analysis revealed that FcFT1 mRNA expression increased under relative long-day and short-day conditions, but not under continuous darkness.ConclusionThese results suggest that FcFT1 activation is regulated by light conditions and may contribute to fig’s unique fruit-setting characteristics.

【 授权许可】

CC BY   
© Ikegami et al.; licensee BioMed Central Ltd. 2013