FLOWERING LOCUS T protein may act as the long-distance florigenic signal in the cucurbits
FLOWERING LOCUS T protein may act as the long-distance florigenic signal in the cucurbits
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DOI：
10.1105/tpc.107.051920
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发表时间：
2007-05-01
期刊：
影响因子：
11.6
通讯作者：
Lucas, William J.
中科院分区：
文献类型：
--
作者：
Lin, Ming-Kuem;Belanger, Helene;Lucas, William J.
使用 Cucurbita moschata（一种对诱导短日照 (SD) 光周期敏感的葫芦科植物）和西葫芦黄花叶病毒 (ZYMV) 来测试花诱导是否需要 FLOWERING LOCUS T (FT) mRNA 或 FT 的长距离移动。 ZYMV 的 FT 异位表达对于介导长日照 (LD) 处理植物的花诱导非常有效。此外，ZYMV 的感染区远离花分生组织，表明 FT 转录本在该系统中不起成花信号的作用。异种嫁接证明了开花信号从开花的南瓜砧木到LD生长的C. moschata接穗的有效传递。对从 C. maxima 种群收集的韧皮部汁液进行实时 RT-PCR 检测，未检测到 FT 转录物，而韧皮部汁液蛋白的质谱分析显示 Cm-FTL1 和 Cm-FTL2 的存在。重要的是，对 LD 和 SD 处理的 C. moschata 植物的研究表明，Cmo-FTL1 和 Cmo-FTL2 在进入韧皮部的水平上受光周期调节，而不是受转录调节。最后，花诱导的异质嫁接 C. moschata 接穗的质谱分析显示，C. maxima FT（而非 FT mRNA）穿过韧皮部易位流中的嫁接联合。总的来说，这些研究与 FT 作为葫芦科植物成花信号系统的组成部分的作用一致。
Cucurbita moschata, a cucurbit species responsive to inductive short-day (SD) photoperiods, and Zucchini yellow mosaic virus (ZYMV) were used to test whether long-distance movement of FLOWERING LOCUS T (FT) mRNA or FT is required for floral induction. Ectopic expression of FT by ZYMV was highly effective in mediating floral induction of long-day (LD)-treated plants. Moreover, the infection zone of ZYMV was far removed from floral meristems, suggesting that FT transcripts do not function as the florigenic signal in this system. Heterografting demonstrated efficient transmission of a florigenic signal from flowering Cucurbita maxima stocks to LD-grown C. moschata scions. Real-time RT-PCR performed on phloem sap collected from C. maxima stocks detected no FT transcripts, whereas mass spectrometry of phloem sap proteins revealed the presence of Cm-FTL1 and Cm-FTL2. Importantly, studies on LD- and SD-treated C. moschata plants established that Cmo-FTL1 and Cmo-FTL2 are regulated by photoperiod at the level of movement into the phloem and not by transcription. Finally, mass spectrometry of florally induced heterografted C. moschata scions revealed that C. maxima FT, but not FT mRNA, crossed the graft union in the phloem translocation stream. Collectively, these studies are consistent with FT functioning as a component of the florigenic signaling system in the cucurbits.