Institute of Plant Sciences, Agricultural Research Organization, The Volcani Center, PO Box 6, Bet Dagan 50250, Israel.
J Plant Physiol. 2011 Nov 1;168(16):1993-6. doi: 10.1016/j.jplph.2011.05.022. Epub 2011 Jul 28.
Strigolactones (SLs) or closely related molecules were recently identified as phytohormones, acting as long-distance branching factors that suppress growth of pre-formed axillary buds in the shoot. The SL signaling pathways and light appear to be connected, as SLs were shown to induce light-regulated pathways and to mimic light-adapted plant growth. However, it is not yet clear how light affects SL levels. Here, we examined the effect of different light intensities on SL levels in tomato roots. The results show that light intensity, above a certain threshold, is a positive regulator of SL levels and of Sl-CCD7 transcription; Sl-CCD7 is involved in SLs biosynthesis in tomato. Moreover, SL accumulation in plant roots is shown to be a time-dependent process. At least some of the similar effects of light and SLs on plant responses might result from a positive effect of light on SL levels.
独脚金内酯（SLs）或密切相关的分子最近被确定为植物激素，作为远距离分枝因子，抑制茎中已形成的腋芽的生长。SL 信号通路和光似乎是相连的，因为 SLs 被证明可以诱导光调控途径并模拟光适应的植物生长。然而，目前尚不清楚光如何影响 SL 水平。在这里，我们研究了不同光照强度对番茄根系 SL 水平的影响。结果表明，光照强度超过一定阈值时，是 SL 水平和 Sl-CCD7 转录的正调节剂；Sl-CCD7 参与番茄 SLs 的生物合成。此外，植物根系中 SL 的积累是一个时间依赖性过程。光和 SLs 对植物反应的至少一些相似影响可能是由于光对 SL 水平的正效应。
