盐碱胁迫对菊芋渗透调节及抗氧化酶系统的影响

Effects of saline-alkali stress on organic osmoregulatory substances and antioxidant enzyme systems of Helianthus tuberosus

为揭示植物在盐碱胁迫下的生理响应,选择菊芋(Helianthustuberosus)为研究对象,设置营养土组(CK)、轻度盐碱土组(LS)和中度盐碱土组(MS)3个不同处理,研究不同盐碱胁迫强度下菊芋有机渗透调节物质(可溶性糖、可溶性蛋白、脯氨酸)、丙二醛(MDA)含量以及抗氧化酶系统活性[超氧化物歧化酶(SOD)、过氧化物歧化酶(POD)、过氧化氢酶(CAT)]等生理指标的变化。研究结果表明:(1)不同盐碱胁迫强度下菊芋叶片可溶性糖、脯氨酸和可溶性蛋白等有机渗透调节物质含量均出现增加。(2)各组间MDA含量无显著差异,随着盐碱胁迫强度的增加,菊芋叶片SOD、POD、CAT等抗氧化酶系统活性指标均表现出上升趋势。与同期CK组相比,盐碱胁迫150d,LS和MS组SOD活性分别显著增加22.13%和26.49%,LS和MS组CAT活性较CK组分别显著增加81.66%和92.38%(P<0.05),MS组POD活性在测定期间均显著高于同期CK组。上述研究结果表明在盐碱胁迫下,菊芋通过增加体内渗透调节物质(可溶性糖、可溶性蛋白、脯氨酸)含量和激活抗氧化酶系统(SOD、CAT、POD)来提高其抗性,具有较强耐盐碱能力。

To reveal the physiological response of typical crops to saline-alkali stress,we selected Jerusalem artichoke(Helianthus tuberosus)as our research object.We set up three different treatments:a complete nutrient soil group(CK),a light saline-alkali soil group(LS),and a moderate saline-alkali soil group(MS).Changes in physiological indicators,such as organic osmoregulatory substances(soluble sugar,soluble protein,and proline);malondialdehyde(MDA)content;and activities of antioxidant enzyme systems[superoxide dismutase(SOD),peroxide dismutase(POD),and catalase(CAT)]of Helianthus tuberosus were investigated.The results showed the following:(1)The content of organic osmoregulatory substances in Jerusalem artichoke leaves,including soluble sugar,proline,and soluble protein,increased under different intensities of saline-alkali stress.(2)The groups had no significant differences in MDA content.However,with increased saline-alkali stress intensity,the activity indexes of antioxidant enzyme systems,such as SOD,POD,and CAT,in Jerusalem artichoke leaves showed an upward trend.After 150 days of saline-alkali stress,the SOD activity in the LS and MS groups increased significantly by 22.13%and 26.49%,respectively,compared to the CK group.Additionally,CAT activity in the LS and MS groups increased significantly by 81.66%and 92.38%,respectively,compared to the CK group(P<0.05).Moreover,POD activity in the MS group was significantly higher than in the CK group during the same period.The above findings demonstrate that Helianthus tuberosus can adapt to a saline-alkali environment by increasing the content of osmoregulatory substances(soluble sugar,soluble protein,and proline)and activating the antioxidant enzyme system(SOD,CAT,and POD),indicating its strong tolerance to saline alkali stress.