School of Life Sciences, Yunnan University, Kunming, 650091, PR China; Flower Research Institute of Yunnan Academy of Agricultural Sciences, Kunming, Yunnan, 650205, PR China.
Univ Lyon, UJM-Saint-Etienne, CNRS, BVpam FRE 3727, F-42023, Saint-Etienne, France.
Plant Physiol Biochem. 2018 Aug;129:21-26. doi: 10.1016/j.plaphy.2018.05.015. Epub 2018 May 10.
The floral volatile compound eugenol is an important constituent in many aromatic plants, being a floral attractant for pollinators as well as having antimicrobial activity. Rose flowers emit eugenol and its derivatives. We recently reported a eugenol synthase gene (RcEGS1) (JQ522949) that was present in petals of R. chinensis cv. Old Blush. RcEGS1 has its highest expression levels in the petals compared to other tissues; it has higher transcript levels at the developmental blooming stage and lower levels at budding and senescence stages. Here, we overexpressed the RcEGS1 protein in Escherichia coli, and showed by Western-blot analysis that its expression was mainly detected in stamens and petals at the flower opening stage. RcEGS1 was principally localized in the upper and lower epidermal layers, which are the major sites of scent emission in roses. Furthermore, we demonstrated that down-regulation of RcEGS1 expression in flowers by virus-induced gene silencing led to a reduction of the relative content of eugenol. We suggested that RcEGS1 was responsible for eugenol biosynthesis in roses.
花香挥发性化合物丁香酚是许多芳香植物的重要组成部分，作为花的引诱剂吸引传粉者，同时具有抗菌活性。玫瑰花朵会散发丁香酚及其衍生物。我们最近报道了一种存在于中国月季 cv. Old Blush 花瓣中的丁香酚合酶基因（RcEGS1）（JQ522949）。与其他组织相比，RcEGS1 在花瓣中的表达水平最高；在发育开花阶段的转录水平较高，在萌芽和衰老阶段较低。在这里，我们在大肠杆菌中过表达了 RcEGS1 蛋白，并通过 Western-blot 分析表明，其表达主要在花开放阶段的雄蕊和花瓣中检测到。RcEGS1 主要定位于上下表皮层，这是玫瑰气味散发的主要部位。此外，我们通过病毒诱导的基因沉默证明了在花朵中下调 RcEGS1 的表达导致丁香酚的相对含量减少。我们认为 RcEGS1 负责玫瑰中丁香酚的生物合成。
