PEG-6000模拟干旱胁迫对三七幼苗生理影响及耐旱性评价  

Physiological Effects and Drought Resistance Evaluation of Panax Notoginseng Seedlings under Drought Stress by PEG-6000

作　　者：黄博原 李晓琳[2] 邓志军 黄荟 HUANG Boyuan;LI Xiaolin;DENG Zhijun;HUANG Hui(Hubei Key Laboratory of Biologic Resources Protection and Utilization,Hubei Minzu University,Enshi 445000,Hubei;China Academy of Chinese Medical Sciences,Beijing 100700;Key Laboratory of Research and Utilization of Ethnomedicinal Plant Resources of Hunan Province,College of Biological and Food Engineering,Huaihua University,Huaihua 418000,Hubei,China)

机构地区：[1]湖北民族大学生物资源保护与利用湖北省重点实验室,湖北恩施445000 [2]中国中医科学院中药资源中心,道地药材品质保障与资源持续利用全国重点实验室,北京100700 [3]怀化学院,生物与食品工程学院,湖南怀化418000

出　　处：《普洱学院学报》2024年第3期20-26,共7页Journal of Pu'er University

基　　金：国家自然科学基金项目(81874334)。

摘　　要：为了解三七幼苗在干旱胁迫下的生理响应,并进行耐旱性评价,以一年生的一叶期三七幼苗为试材,采用不同浓度梯度(5%、10%、15%和20%)的PEG-6000溶液处理12h和24h模拟不同程度的干旱胁迫,以H_(2)O处理0h-24h为对照,分别测定叶片的相对含水量(WC)、丙二醛(MDA)、脯氨酸(Pro)、过氧化氢酶(CAT)、过氧化物酶(POD)、超氧化物歧化酶(SOD)和叶绿素(Chl)含量等生理指标,以期为三七幼苗的栽培种植提供理论依据。结果表明:随着PEG-6000溶液浓度和处理时间的增加,叶片相对含水量和叶绿素含量明显减低,而丙二醛和脯氨酸含量显著上升,过氧化氢酶、过氧化物酶、超氧化物歧化酶三种抗氧化酶活性呈先上升后下降的趋势。在此基础上,构建了三七幼苗的综合耐旱性的隶属函数评价,15%PEG-6000处理24h时耐旱性最强。由此可见,干旱胁迫较轻时,一叶期三七幼苗叶片会诱导脯氨酸和抗氧化酶以增强耐旱性,然而干旱胁迫加剧时,叶片抗氧化系统活性显著减低,导致叶片生理代谢紊乱,其耐旱性随之降低。In order to study the physiological response of Panax notoginseng seedlings under drought stress and evaluate their drought resistance,one-year-old seedlings at the single-leaf stage were used as materials in our study.PEG-6000 solutions (5%,10%,15%,and 20%) were used to simulate different degrees of drought stress to treat P.notoginseng seedlings for 12 h and 24 h,with H2O treatment at 0 hours as the control.The relative water content,the levels of malondialdehyde (MDA),proline and chlorophyll,and the activities of catalase,peroxidase and superoxide dismutase of leaves were measured to provide theoretical basis for the cultivation and planting of P.notoginseng seedlings.The results showed that with the increasing of PEG-6000 concentration and treatment time,the relative water content and chlorophyll content of leaves decreased significantly,while the MDA and proline contents increased significantly.The activities of antioxidant enzymes showed an initial increase followed by a decrease trend.Based on those results,the subordinate function values and drought resistance evaluation was preformed,showing that the strongest drought resistance under 15%PEG-6000 treatment for 24 h.Thus,these results indicated that P.notoginseng seedlings at the single-leaf stage increased proline content and antioxidant enzymes activities to enhance drought resistance under mild drought stress.However,as drought stress intensifies,the activity of the antioxidant system significantly decreases,leading to physiological metabolic disorders and a decrease in their drought tolerance.

关 键 词：干旱胁迫 抗氧化酶 耐旱评价 

分 类 号：Q943.1[生物学—植物学]