Gray Dean E, Pallardy Stephen G, Garrett H E, Rottinghaus George E
Midwest Research Institute, Kansas City, Missouri 64110, USA.
Planta Med. 2003 Nov;69(11):1024-30. doi: 10.1055/s-2003-45150.
The phytochemistry and dry weight of cultivated St. John's wort are significantly influenced by acute drought stress and time of harvest. In this study, plants subjected to brief drought stress during both flower and seed development periods exhibited increased concentrations in 8 of the 10 phytochemicals examined in this study, including hypericin, pseudohypericin, chlorogenic acid, rutin, hyperoside, isoquercitrin, quercitrin, and quercetin. Increases ranged from 5% to 36% (hyperoside and rutin, respectively). Conversely, the concentrations of hyperforin and adhyperforin in flowers were decreased by an average of 10% in drought-stressed plants as compared to well-watered control plants. Acute drought stress decreased flower dry weight significantly during both drydown periods, although vegetative parameters (height, leaf dry weight and stem dry weight) were not adversely affected. While acute drought stress significantly altered the chemical yield in the leaves and flowers (phytochemical content x harvested dry weight), the time of harvest was the predominant factor determining phytochemical concentration in the organs of H. perforatum.
栽培的贯叶连翘的植物化学组成和干重受到急性干旱胁迫和收获时间的显著影响。在本研究中，在花期和种子发育期均遭受短暂干旱胁迫的植株，在本研究检测的10种植物化学物质中的8种物质含量增加，包括金丝桃素、假金丝桃素、绿原酸、芦丁、金丝桃苷、异槲皮苷、槲皮苷和槲皮素。增加幅度在5%至36%（分别为金丝桃苷和芦丁）之间。相反，与充分浇水的对照植株相比，干旱胁迫植株花朵中的贯叶连翘素和去甲贯叶连翘素含量平均降低了10%。在两个干涸期，急性干旱胁迫均显著降低了花朵干重，不过营养参数（株高、叶干重和茎干重）未受到不利影响。虽然急性干旱胁迫显著改变了叶片和花朵中的化学产量（植物化学物质含量×收获时的干重），但收获时间是决定贯叶连翘器官中植物化学物质浓度的主要因素。
