2种鼠尾草对NaCl胁迫的耐受性比较及其生理机制研究

以具有较高药用和观赏价值的美丽鼠尾草和贵州鼠尾草为实验材料,分析2种鼠尾草在NaCl(0、200、300、400、500、600mmol·L-1)胁迫下的生长、叶绿素含量、保护酶活性和有机渗透调节物质含量的变化,以明确2种鼠尾草对NaCl胁迫的耐受性差异及其生理机制。结果显示:(1)在实验NaCl浓度范围内,美丽鼠尾草的受害程度均高于贵州鼠尾草;(2)随着NaCl浓度的提高,贵州鼠尾草叶片叶绿素含量无显著变化,而美丽鼠尾草叶绿素含量逐渐显著降低;(3)当NaCl浓度从0增加到500mmol·L-1时,2种鼠尾草叶片的POD、CAT活性以及可溶性糖、可溶性蛋白质和脯氨酸含量逐渐升高,且美丽鼠尾草叶片的SOD活性也逐渐升高;(4)当NaCl浓度达到600mmol·L-1时,美丽鼠尾草叶片可溶性糖、可溶性蛋白质和脯氨酸含量继续增加,SOD、POD和CAT活性开始降低但仍显著高于对照,而贵州鼠尾草叶片的POD和CAT活性继续增加,可溶性糖、可溶性蛋白质和脯氨酸含量开始降低但仍显著高于对照。研究表明,贵州鼠尾草在NaCl胁迫下具有较高的渗透调节物质含量,而且随着NaCl浓度的增加能够维持较高的保护酶活性,因此对NaCl胁迫的耐受性强于美丽鼠尾草。

Comparation of Tolerance under NaCl Stress between Two Salvia Plants and Study of the Physiological Mechanisms

In order to ensure different tolerances of two Salvia plants to NaCl stress and its physiological mechanism,we used S.meiliensis and S.cavaleriei with high medicinal and ornamental value as experimental materials to analyze the variation of their growth,chlorophyll content,protective enzymes activities and their content of organic osmotic regulation substances under 0,200,300,400,500 and 600 mmol·L^-1NaCl.The results showed that:1)under each concentration of NaCl stress,S.meiliensis suffered from the salt damage more severely than S.cavaleriei.As NaCl concentrations increased.2)The chlorophyll content in the leaves of S.cavaleriei had no significant change,but those in the leaves of S.meiliensis decreased gradually.3) When NaCl concentration increased from 0 to 500 mmol·L^-1,S.cavaleriei and S.meiliensis plants responded adaptively to NaCl stress.The POD and CAT activities,as well as soluble sugar,soluble protein and proline contents gradually inceased in the leaves of S.cavaleriei and S.meiliensis.The SOD activity also increased in the leaves of S.meiliensis.4) When NaCl concentration reached to 600 mmol·L^-1,the soluble sugar,soluble protein and proline contents in the leaves of S.meiliensis continued to increase,while the SOD,POD and CAT activities started to drop,but were still significantly higher than those of the control.In contrast,at the same NaCl concentration,the POD and CAT activities in the leaves of S.cavaleriei continued to increase.The soluble sugar,soluble protein and proline contents started to drop,but were still significantly higher than those of the control.S.cavaleriei possesses higher contents of osmotic regulation substances under NaCl stress and can maintain higher protective enzymes activities with increase of NaCl concentration,it has stronger tolerance to NaCl than S.meiliensis.