Research Centre for Plant RNA Signaling, School of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou. 310036, China.
Sci Rep. 2011;1:73. doi: 10.1038/srep00073. Epub 2011 Aug 24.
In inducing photoperiodic conditions, plants produce a signal dubbed "florigen" in leaves. Florigen moves through the phloem to the shoot apical meristem (SAM) where it induces flowering. In Arabidopsis, the FLOWERING LOCUS T (FT) protein acts as a component of this phloem-mobile signal. However whether the transportable FT mRNA also contributes to systemic florigen signalling remains to be elucidated. Using non-conventional approaches that exploit virus-induced RNA silencing and meristem exclusion of virus infection, we demonstrated that the ArabidopsisFT mRNA, independent of the FT protein, can move into the SAM. Viral ectopic expression of a non-translatable FT mRNA promoted earlier flowering in the short-day (SD) Nicotiana tabacum Maryland Mammoth tobacco in SD. These data suggest a possible role for FT mRNA in systemic floral signalling, and also demonstrate that cis-transportation of cellular mRNA into SAM and meristem exclusion of pathogenic RNAs are two mechanistically distinct processes.
在诱导光周期条件下，植物在叶片中产生一种被称为“成花素”的信号。成花素通过韧皮部移动到茎尖分生组织（SAM），在那里诱导开花。在拟南芥中，开花时间基因（FT）蛋白作为这种韧皮部移动信号的组成部分。然而，可运输的 FT mRNA 是否也有助于系统成花素信号传导仍有待阐明。本研究利用病毒诱导的 RNA 沉默和分生组织排除病毒感染的非传统方法，证明了拟南芥FT mRNA 可以独立于 FT 蛋白进入 SAM。在短日照（SD）条件下，烟草花叶病毒异位表达一种不翻译的 FT mRNA 促进了马里兰州巨型烟草的提前开花。这些数据表明 FT mRNA 可能在系统花信号传导中发挥作用，也证明了细胞 mRNA 的顺式运输进入 SAM 和病原 RNA 的分生组织排除是两个在机制上不同的过程。
