人参对干旱胁迫的生理生化反应

Physiological and Biochemical Response of Panax ginseng C.A. Meyer to Drought Stress

以3年生人参幼苗为研究材料,采用盆栽试验设计,研究干旱胁迫时间对人参幼苗叶片相对含水量与质膜损伤状况,以及叶绿素、抗氧化物谷胱甘肽(GSH)含量和抗氧化保护酶(SOD、POD)活性的影响。结果显示:与同期对照(适宜水分处理)相比,干旱胁迫下人参叶片含水量随胁迫时间的延长显著降低;同时,叶绿素与可溶性蛋白含量也随胁迫时间的延长显著下降。丙二醛含量与电解质渗漏较对照组显著增加,并随胁迫时间的延长而升高。抗氧化酶SOD和POD活性高于对照组,随胁迫时间的延长先增加后下降;抗氧化物谷胱甘肽(GSH)含量低于对照组,随胁迫时间的延长呈现降-升-降的变化规律。研究表明,干旱胁迫会对人参幼苗造成一定伤害,但在前期能调动自身抗氧化保护酶类与抗氧化物质提高其抗旱能力,但随着胁迫时间的延长抗氧化能力降低。

The pot experiment was conducted to study the effects of different time of drought stress treatments on physiological and biochemical characteristics （RWC, MDA, EL, chlorophyll content, SP, SOD, POD and GSH） of 3- year-old Panax ginseng C. A. Meyer seedlings. Results showed that compared with control （suitable soil moisture treatment）, leaf relative water content （RWC） in Panax ginseng C. A. Meyer seedlings decreased significantly. Chlo- rophyll （Chl a, Chl b, Car） and soluble protein （SP） content also decreased significantly as drought stress time pro- longed. The content of MDA and EL were higher than control and increased significantly when drought stress time prolonged. The activities of SOD and POD were higher than control and first increased at first and then decreased as the time of drought stress treatments prolonged. The content of GSH was lower than control and followed a changing pattern of fall-rise-fall. The research found Panax ginseng C. A. Meyer seedlings was vulnerable to damage by se- vere drought stress. The antioxidant enzyme and metabolites was adjusted to increase its antioxidant capability, but the capability had already fall down obviously by prolonged drought stress.