材料，研究了聚乙二醇（PEG 6000）模拟干旱胁迫对其各部位抗氧化酶、渗透物质和根系活力等生理指标的影响。结果表明，根和叶中POD，APX活力随处理浓度（PEG 6000 0，2.5%，5.0%，7.5%）和时间（1，2，3 d）的增加而不断上升，SOD则表现为在同一处理时间下随处理浓度的增加而先升后降，同一处理浓度下则随处理时间的延长而上升，CAT活性表现为在同一处理时间下随处理浓度的增加而增加，同一处理浓度下则随处理时间的延长而呈先升高后降低的趋势;茎中SOD，APX活性变化不明显，CAT活性随处理时间和浓度的增加而升高;根和叶中MDA、可溶性蛋白和脯氨酸含量及根系活力随处理浓度的升高和处理时间的延长而显著升高;处理1 d 后，根尖H<sub>2</sub>O<sub>2</sub>和NO荧光信号随处理浓度的升高而增强。综上所述，三七幼苗能够通过调节抗氧化酶系统、渗透胁迫物质及抗逆胁迫信号物质应对干旱胁迫，当PEG 6000超过5.0%（即溶液水势为-0.50 MPa）时可对三七幼苗产伤害，应及时补水抗旱。
[关键词] 三七;干旱胁迫;抗氧化酶;渗透物质;根系活力;信号物质
[收稿日期] 2015-04-13
[基金项目] 国家自然科学基金项目（81360617，81460580）;云南省战略性新兴产业发展转型资金项目;昆明理工大学分析测试基金项目（20140743）
[通信作者] *崔秀明，E-mail：sanqi37@vip.sina.com;*杨野，E-mail：yangyekm@163.com
Effect of Panax notoginseng seedlings physiological response under
simulated drought stress by polyethylene glycol （PEG 6000）
LIAO Pei-ran1， CUI Xiu-ming1*， YANG Ye1*， LI Zi-wei1， GE Jin1， WANG Cheng-xiao1， YANG Xiao-yan1， LIU Da-hui2
（1.Kunming Key Laboratory of Sustainable Development and Utilization of Famous-region Drug， Faculty of Life
Science and Technology， Kunming University of Science and Technology， Kunming 650500， China;
2.Institute of Medicinal Plants， Yunnan Academy of Agriculture Science， Kunming 650231， China）
[Abstract] The physiological effects of Panax notoginseng seedlings under simulated drought stress by PEG 6000 on antioxidant enzymes， osmotic substances and root activities were studied. The results showed that the activity of POD and APX in roots and leaves kept rising with increasing processing concentration and time. However， on the one hand， at the same processing time， SOD in roots and leaves firstly increased and then decreased with the increase of processing concentration. On the other hand， at the same processing concentration， SOD kept rising with the extension of processing time. In addition， the activity of CAT in roots and leaves tended to increase with the increasing concentration at the same processing time， while it increased at first and then decreased with the extension of time at the same concentration. The activity of SOD and APX in stem did not change obviously， whereas CAT activity in stem increased with the increasing processing time and concentration. With the increase of processing concentration and the extension of processing time， the MDA， soluble protein， proline content and root activity in leaves and roots apparently rose. Moreover， fluorescence signal of H<sub>2</sub>O<sub>2</sub> and NO in root tip enhanced as the processing concentration increased after treated for 1d. In summary， P. notoginseng seedlings could deal with drought stress by means of adjusting the system of antioxidant enzyme， permeating stress substances and impeded stress signal substances. Thus， when the concentration of PEG 6000 was more than 5%， it would have harm on P. notoginseng seedlings.
