油菜素内酯对盐胁迫下黄芩幼苗生理生化特性的影响

Effects of Brassinolide on Physiological and Biochemical Characteristics of Scutellaria baicalensis Seedlings under Salt Stress

为揭示油菜素内酯(BR)对盐胁迫下黄芩的生理变化规律,以黄芩幼苗作为试验材料,在0.5%NaCl胁迫下,采用喷施叶片的处理方法,分别施加不同浓度的BR(0.1、0.2、0.3、0.4、0.5 mg/L)处理黄芩幼苗后,通过测定其相关生理指标,比较分析盐胁迫下黄芩幼苗生理生化特性的变化规律。结果表明:在0.5%NaCl胁迫下,适宜质量浓度的BR可提高叶片抗氧化能力、清除叶片中的活性氧、保护膜结构、缓解盐胁迫对黄芩幼苗的伤害,从而提高黄芩幼苗的抗盐性;施加不同浓度的BR能提高叶片SOD、POD、CAT保护酶的活性及其脯氨酸含量,并降低MDA含量;在0.1~0.5 mg/L BR的浓度梯度中,以0.4和0.5 mg/L BR的处理效果较好,但BR最佳浓度的确定还有待进一步研究。

In order to reveal the physiological changes of brassinolide(BR)under salt stress,the Scutellaria baicalensis seedlings were used as test materials.Under the condition of 0.5%salt stress,different concentrations of BR(0.1,0.2,0.3,0.4 and 0.5 mg/L)were applied.The physiological and biochemical characteristics of Scutellaria baicalensis seedlings were compared and analyzed under salt stress.The results showed that under the condition of 0.5%salt stress,suitable concentration of BR could increase the antioxidant capacity of leaves,remove active oxygen in leaves,protect membrane structure,alleviate the damage of salt stress on Scutellaria baicalensis seedlings and improve the salt tolerance of Astragalus membranaceus seedlings.The application of different concentrations of BR increased the superoxide dismutase(SOD)and peroxidase(POD),catalase(CAT)activities in leaves and their proline contents,and reduced the malondialdehyde content.In the 0.1~0.5 mg/L BR concentration gradient,the effect of 0.4 and 0.5 mg/L was better,but the determination of the optimal concentration of BR remained to be further studied.