植物生长调节剂S_(3307)对苗期淹水胁迫下大豆生理特性和显微结构的影响

Effects of uniconazole on physiological characteristics and microstructure under waterlogging stress at seedling stage in soybean

为探究苗期(V1期)淹水胁迫对大豆生理特性和显微结构的影响及烯效唑(S_(3307))的缓解效应,以‘垦丰14’为材料,于V1期进行叶面喷施S_(3307),并于喷药后5d进行淹水处理,对淹水胁迫下大豆叶片和根系生理特性、下胚轴显微结构及S_(3307)的调控效应进行了测定和分析。结果表明,淹水胁迫会增加大豆下胚轴通气组织数量,随淹水胁迫时间延长,通气组织面积逐渐增大;S_(3307)能提高大豆对淹水逆境的适应性,增加通气组织数量和通气组织的面积,以应对淹水胁迫对植株造成的缺氧胁迫。与对照(CK)相比,淹水胁迫会增加叶片和根系中活性氧(ROS)和丙二醛(MDA)含量,并随胁迫时间延长而逐渐升高。在淹水胁迫前期会诱导酶促抗氧化防御系统活性的增强,引起渗透调节物质含量的增加,随胁迫时间延长,抗氧化酶活性和渗透调节物质含量均呈下降趋势。S_(3307)可促进叶片和根系中抗氧化酶活性的提高,抑制ROS和MDA含量的过量积累,并始终维持较高的渗透调节物质含量,减缓淹水胁迫造成的损伤。

To explore the effects of waterlogging stress on the physiological characteristics and microstructure of soybean and the mitigation effect of S_(3307), the physiological characteristics of soybean leaves and roots, the microstructure of hypocotyls and the regulation effect of S_(3307) were investigated using Kenfeng 14 as the experimental material with S_(3307) sprayed on the leaves of soybean at V1 stage and five days after waterlogging stress in a pot experiment. The results showed that waterlogging stress increased the number of ventilated tissues in soybean hypocotyl, and the area of ventilated tissues increased gradually with the prolongation of waterlogging stress. S_(3307) could improve soybean adaptability to waterlogging adversity, increase the number of ventilated tissue and cope with the hypoxia stress by waterlogging stress on plants. Compared with CK, waterlogging stress increased the accumulation of ROS and membrane lipid peroxidation in leaves and roots, and gradually increased with the prolongation of stress time. Meanwhile, the activity of enzymatic antioxidant defense system was enhanced at early stage under waterlogging stress, resulting in an increase in the content of osmotic regulatory substances, which decreased with the prolongation of stress time. S_(3307) can promote the activity of antioxidant enzyme in leaves and roots, inhibit the excessive accumulation of ROS and MDA content, maintain a high content of osmotic regulation substances, and alleviate the damage caused by waterlogging stress. In summary, there were differences in response to different organs under waterlogging stress. S_(3307) can alleviate the damage to soybean plants caused by waterlogging stress to a certain extent.