干旱胁迫对甘草幼苗生长和渗透调节物质含量的影响

Growth and Osmoregulation Substances Accumulation of Glycyrrhiza uralensis Seedling under Drought Stress

采用人工控制水分模拟干旱的处理方法,研究了干旱胁迫对甘草幼苗生长状况、水分状况和主要渗透调节物质含量的影响。结果显示:轻度干旱胁迫有利于甘草幼苗根系生长,植株根冠比加大。干旱胁迫下甘草根叶组织中相对含水量下降,束缚水/自由水升高。甘草幼苗组织中渗透调节物质可溶性蛋白、游离脯氨酸、可溶性糖含量在干旱胁迫下也均显著增加;且不同胁迫程度和不同器官渗透调节物质增幅有较大差异,其中在轻度和中度胁迫下可溶性糖和游离脯氨酸含量分别在甘草根组织与叶组织中含量增幅大,可溶性蛋白含量增加均出现在胁迫后期。研究表明,干旱胁迫下甘草植株能通过调整生长和生物量分配来加大根冠比;同时通过积累渗透调节物质来提高植株的吸水和保水能力,有效抵御干旱逆境;可溶性糖与游离脯氨酸可能分别是甘草根、叶获得渗透调节能力的重要渗透调节物质。

Using artificial control of water treatment method of simulated drought,we investigated Glycyrrhiza uralensis seedling growth situation,moisture status and the main osmotic regulation substance contents.The results showed that：moderate drought favored the root growth,plant root-shoot ratio increased;G.uralensis root and leaf tissue relative water content declined under drought stress;bound water/free water rose;Correspondingly,the main osmotic regulation substances in G.uralensis seedling such as soluble protein,free proline,soluble sugar contents were significantly increased under drought stress;Osmoregulation substance accumulation had a big difference under different stress levels and in different organs.During early and middle stage of drought stress,the soluble sugar and free proline contents in G.uralensis root tissue and leaf tissue highly accumulated separately.The soluble protein content increased during later stage of drought stress.The results indicated that：G.uralensis plant can effectively defend drought adversity through adjusting growth,the biomass allocation and increase root-shoot ratio under drought stress,and through the accumulation of osmoregulation substances to improve plant water absorption and water-retaining capacity.Soluble sugar and free proline are G.uralensis licorice root and leaf important osmoregulation substances to keep osmotic adjustment ability.