Institute of Plant Sciences, Agricultural Research Organization (ARO), the Volcani Center, Bet Dagan, Israel.
J Exp Bot. 2010 Jun;61(11):3129-36. doi: 10.1093/jxb/erq138. Epub 2010 May 25.
Strigolactones are newly identified plant hormones, shown to participate in the regulation of lateral shoot branching and root development. However, little is known about their effects on biological processes, genes, and proteins. Transcription profiling of roots treated with GR24, a synthetic strigolactone with proven biological activity, and/or indole acetic acid (IAA) was combined with physiological and transcriptional analysis of a tomato mutant (Sl-ORT1) deficient in strigolactone production. GR24 treatment led to markedly induced expression of genes putatively involved in light harvesting. This was apparent in both the presence and absence of exogenously applied IAA, but not with IAA treatment alone. Following validation of the microarray results, transcriptional induction by light of the GR24-induced genes was demonstrated in leaves exposed to high or low light intensities. Sl-ORT1 contained less chlorophyll and showed reduced expression of light harvesting-associated genes than the wild type (WT). Moreover, perfusion of GR24 into WT and Sl-ORT1 leaves led to induction of most of the examined light harvesting-associated genes. Results suggest that GR24 treatment interferes with the root's response to IAA treatment and that strigolactones are potentially positive regulators of light harvesting in plants.
独脚金内酯是新发现的植物激素，参与调控侧芽分枝和根系发育。然而，人们对其在生物过程、基因和蛋白质方面的作用知之甚少。用 GR24（一种具有生物活性的合成独脚金内酯）和/或吲哚乙酸（IAA）处理根系后进行转录谱分析，并结合对缺乏独脚金内酯合成的番茄突变体（Sl-ORT1）进行生理学和转录分析。GR24 处理导致与光捕获相关的基因的表达明显上调。这在有和没有外源施加的 IAA 的情况下都很明显，但单独用 IAA 处理则不然。在验证了微阵列结果后，在暴露于高光或低光强度的叶片中证明了 GR24 诱导的基因的光诱导转录。Sl-ORT1 比野生型（WT）含有较少的叶绿素，并且表现出与光捕获相关基因的表达降低。此外，将 GR24 灌注到 WT 和 Sl-ORT1 叶片中会诱导大多数检查的与光捕获相关的基因的表达。结果表明，GR24 处理干扰了根系对 IAA 处理的反应，并且独脚金内酯可能是植物中光捕获的正向调节剂。
