通过探究水分胁迫对裸果木幼苗根系和叶片抗氧化特性的影响，为提高裸果木的抗旱能力提供参考。以裸果木幼苗为试材，通过盆栽控制实验，设置了轻度干旱胁迫、中度干旱胁迫和重度干旱胁迫处理，研究在水分胁迫下裸果木幼苗根系和叶片抗坏血酸过氧化物酶(APX)、过氧化氢酶(CAT)、超氧化物歧化酶(SOD)、过氧化物酶(POD)活性和丙二醛(MDA)含量的变化。结果表明，在水分胁迫下，裸果木叶片中的MDA含量在中度和重度水分胁迫下显著增加，根系中的MDA含量在所有胁迫处理下均增加明显，根系对水分胁迫较为敏感；SOD酶活性在根系和叶片中均有明显变化，对膜系统起到一定的保护作用；叶片中POD酶的抗氧化作用较根系明显；叶片和根系的CAT和APX酶的抗氧化作用均明显，但APX酶的作用不明显。综合分析表明，在水分胁迫下，叶片中能够清除活性氧效果显著的酶是CAT和POD，而根系中SOD酶的抗氧化作用较强，叶片和根系对APX酶的作用差异较小。

To provide insights for improving the drought resistance of Gymnocarpos przewalskii, this study investigated the effects of water stress on the antioxidative characteristics of G. przewalskii seedling roots and leaves. Using potted seedlings as materials, treatments were established as mild, moderate, and severe drought stress. The activities of ascorbate peroxidase (APX), catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD), as well as the malondialdehyde (MDA) content, were measured under different water stress levels. Results showed that under water stress, the MDA content in leaves significantly increased under moderate and severe drought conditions, while the MDA content in roots increased markedly across all treatments, indicating that roots were more sensitive to water stress. SOD activity in both roots and leaves changed significantly, providing protection for the membrane system. The antioxidative role of POD was more pronounced in leaves than in roots. CAT and APX in both roots and leaves exhibited antioxidative activity, although APX activity was relatively less significant. Overall, CAT and POD were the key enzymes responsible for reactive oxygen species scavenging in leaves, while SOD played a major antioxidative role in roots, and APX activity showed little difference between the two organs.

Q945.78；S793.9