Institute for Applied Botany and Pharmacognosy, University of Veterinary Medicine, Veterinärplatz 1, 1210 Vienna, Austria.
J Plant Physiol. 2010 Jul 1;167(10):779-86. doi: 10.1016/j.jplph.2009.12.009. Epub 2010 Feb 16.
Common sage (Salvia officinalis L., Lamiaceae) is one of the most important medicinal and aromatic plants, with antioxidant, antimicrobial, spasmolytic, astringent, antihidrotic and specific sensorial properties. The essential oil of the plant, composed mainly of the monoterpenes 1,8-cineole, alpha-thujone, beta-thujone and camphor, is responsible for some of these effects. Gibberellins regulate diverse physiological processes in plants, such as seed germination, shoot elongation and cell division. In this study, we analyzed the effect of exogenously applied plant growth regulators, namely gibberellic acid (GA(3)) and daminozide, on leaf morphology and essential oil formation of two leaf stages during the period of leaf expansion. Essential oil content increased with increasing levels of gibberellins and decreased when gibberellin biosynthesis was blocked with daminozide. With increasing levels of gibberellins, 1,8-cineole and camphor contents increased. Daminozide blocked the accumulation of alpha- and beta-thujone. GA(3) at the highest level applied also led to a significant decrease of alpha- and beta-thujone. Monoterpene synthases are a class of enzymes responsible for the first step in monoterpene biosynthesis, competing for the same substrate geranylpyrophosphate. The levels of gene expression of the three most important monoterpene synthases in sage were investigated, 1,8-cineole synthase leading directly to 1,8-cineole, (+)-sabinene synthase responsible for the first step in the formation of alpha- and beta-thujone, and (+)-bornyl diphosphate synthase, the first step in camphor biosynthesis. The foliar application of GA(3) increased, while daminozide significantly decreased gene expression of the monoterpene synthases. The amounts of two of the end products, 1,8-cineole and camphor, were directly correlated with the levels of gene expression of the respective monoterpene synthases, indicating transcriptional control, while the formation of alpha- and beta-thujone was not transcriptionally regulated.
常见的鼠尾草（Salvia officinalis L.，唇形科）是最重要的药用和芳香植物之一，具有抗氧化、抗菌、平滑肌松弛、收敛、止汗和特殊感官特性。植物的精油主要由单萜 1,8-桉叶油醇、α-侧柏酮、β-侧柏酮和樟脑组成，负责其中一些作用。赤霉素调节植物的多种生理过程，如种子萌发、芽伸长和细胞分裂。在这项研究中，我们分析了外源植物生长调节剂，即赤霉素（GA(3)）和氨基胍，对叶片扩张过程中两个叶片阶段叶片形态和精油形成的影响。随着赤霉素水平的升高，精油含量增加，而用氨基胍阻断赤霉素生物合成时则减少。随着赤霉素水平的升高，1,8-桉叶油醇和樟脑的含量增加。氨基胍阻止了α-和β-侧柏酮的积累。应用的最高 GA(3)水平也导致α-和β-侧柏酮含量显著降低。单萜合酶是负责单萜生物合成第一步的一类酶，竞争相同的底物香叶基焦磷酸。研究了鼠尾草中三种最重要的单萜合酶的基因表达水平，1,8-桉叶油醇合酶直接导致 1,8-桉叶油醇的形成，（+）-柠檬烯合酶负责α-和β-侧柏酮形成的第一步，以及（+）-莰烯二磷酸合酶，樟脑生物合成的第一步。GA(3)的叶面施用增加，而氨基胍显著降低了单萜合酶的基因表达。两种终产物 1,8-桉叶油醇和樟脑的含量与各自单萜合酶的基因表达水平直接相关，表明转录控制，而α-和β-侧柏酮的形成则不受转录调控。
