Physiological drought responses of Glycyrrhiza uralensis leaves under prolonged water stress

Chinese. 为给甘草药材的高效生产提供理论依据,通过人工控制水分模拟干旱来研究甘草对水分胁迫的生理反应,采用完全随机区组设计,设5个水分处理（20%-30%4、0%-50%、60%-70%、80%-90%、100%）,研究水分胁迫对甘草的生长状况、叶片水分状况、渗透调节物质以及保护系统的影响。结果表明：随水分含量的降低,相对含水量（RWC）降低R28,20%-30%和40%-50%处理丙二醛（MDA）含量显著提高,导致膜损伤,质膜透性上升;超氧化物岐化酶（SOD）、过氧化物岐化酶（POD）活性、可溶性糖及脯氨酸（Pro）含量均显著或极显著高于其他处理。说明甘草自身通过抗氧化酶系及渗透调节物质之间的协调维持代谢平衡,但20%-30%处理的生物量显著低于其他处理,说明过度干旱不利于甘草的生长。[著者文摘]

English. The physiological and biochemical responses of Glycyrrhiza uralensis under artificially simulated drought stresses were examined to provide a theoretical basis for effectively increasing agricultural production in arid areas. An experiment was carried out in randomized complete blocks design, including five water treatments （20% --30%, 40% --50%, 60% --70%, 80% --90% , 100% ） to determine drought resistance of the leaves. The following parameters were determined： growth status, relative water content （RWC）, soluble sugars, free praline, rnalondialde-hyde （MDA）,and activities of superoxide dismutase （SOD） and peroxidase （POD）. Under moderate drought stress, the RWC in leaves was decreased, MDA content increased remarkably causing membrane damage and increasing membrane permeability of leaf cells. The activities of SOD and POD, MDA content, solubility sugar and Pro were notably higher. These changes indicated that the plants could maintain the metabolism balance by regulating both antioxidase and osmotic matter under the drought stress, but under 20 % -- 30 % water treatment the biomass was inhibited obviously, which showed that too low content of soil water was not conducive to the growth of Glycyrrhiza uralensis.