Plant Biotechnology Resource and Outreach Center, Department of Horticulture, Michigan State University, East Lansing, MI, 48824, USA,
Plant Cell Rep. 2013 Nov;32(11):1759-69. doi: 10.1007/s00299-013-1489-z. Epub 2013 Aug 2.
The blueberry FLOWERING LOCUS T ( FT )-like gene ( VcFT ) cloned from the cDNA of a tetraploid, northern highbush blueberry ( Vaccinium corymbosum L.) is able to reverse the photoperiodic and chilling requirements and drive early and continuous flowering.
Blueberry is a woody perennial bush with a longer juvenile period than annual crops, requiring vernalization to flower normally. Few studies have been reported on the molecular mechanism of flowering in blueberry or other woody plants. Because FLOWERING LOCUS T (FT) from Arabidopsis thaliana plays a multifaceted role in generating mobile molecular signals to regulate plant flowering time, isolation and functional analysis of the blueberry (Vaccinium corymbosum L.) FT-like gene (VcFT) will facilitate the elucidation of molecular mechanisms of flowering in woody plants. Based on EST sequences, a 525-bpVcFT was identified and cloned from the cDNA of a tetraploid, northern highbush blueberry cultivar, Bluecrop. Ectopic expression of 35S:VcFT in tobacco induced flowering an average of 28 days earlier than wild-type plants. Expression of the 35S:VcFT in the blueberry cultivar Aurora resulted in an extremely early flowering phenotype, which flowered not only during in vitro culture, a growth stage when nontransgenic shoots had not yet flowered, but also in 6-10-week old, soil-grown transgenic plants, in contrast to the fact that at least 1 year and 800 chilling hours are required for the appearance of the first flower of both nontransgenic 'Aurora' and transgenic controls with the gusA. These results demonstrate that the VcFT is a functional floral activator and overexpression of the VcFT is able to reverse the photoperiodic and chilling requirements and drive early and continuous flowering.
从四倍体北方高丛蓝莓（Vaccinium corymbosum L.）的 cDNA 中克隆出的蓝莓开花时间调控点类似基因（VcFT）能够逆转光周期和冷需求，驱动早期和持续开花。
蓝莓是一种木本多年生灌木，其幼年期比一年生作物长，需要春化才能正常开花。关于蓝莓或其他木本植物开花的分子机制的研究很少。由于拟南芥的开花时间调控点 T（FT）在产生移动分子信号以调节植物开花时间方面发挥着多方面的作用，因此蓝莓（Vaccinium corymbosum L.）FT 类似基因（VcFT）的分离和功能分析将有助于阐明木本植物开花的分子机制。基于 EST 序列，从四倍体北方高丛蓝莓品种 Bluecrop 的 cDNA 中鉴定和克隆出一个 525bp 的 VcFT。在烟草中异位表达 35S:VcFT 比野生型植物早开花平均 28 天。35S:VcFT 在蓝莓品种 Aurora 中的表达导致了一个极早开花的表型，不仅在体外培养时开花，在非转基因芽尚未开花的生长阶段开花，而且在 6-10 周龄、土壤种植的转基因植株中开花，而在非转基因“Aurora”和带有 gusA 的转基因对照中，至少需要 1 年和 800 个冷小时才能出现第一朵花。这些结果表明，VcFT 是一个功能性的花激活剂，过表达 VcFT 能够逆转光周期和冷需求，驱动早期和持续开花。
