Lin Kuan-Hung R, Tsou Chao-Chia, Hwang Shih-Ying, Chen Long-Fang O, Lo Hsiao-Feng
Department of Horticulture, Chinese Culture University, 55, Hwa-Gang Road, YangMingShan, Taipei 111, Taiwan, ROC.
J Plant Physiol. 2006 May;163(7):750-60. doi: 10.1016/j.jplph.2005.07.008. Epub 2005 Sep 9.
The objective of this experiment was to study changes of antioxidants and antioxidative enzymes in the flooding-stressed sweet potato leaf, as affected by paclobutrazol (PBZ) treatment at 24 h prior to flooding. Sweet potato 'Taoyuan 2' were treated with 0 and 0.5 mg/plant of PBZ, afterwards subjected to non-flooding and flooding-stress conditions for 0, 1, 3, and 5 d, followed by a 2 d drainage period. The study was conducted as a factorial experiment in completely randomized blocks with three replications maintained within a screen house. Plants with various antioxidative systems responded differently to flooding stress according to the duration of the flooding period and subsequent drainage period. The increased levels of antioxidants and antioxidative enzymes observed on different days of flooding afforded the sweet potato leaf with improved flooding tolerance. Glutathione reductase activity in the leaf was significantly enhanced over 5 d continuous flooding followed by a drainage period, in comparison with non-flooding conditions. Under non-flooding conditions, antioxidative system of leaf was regulated and elevated by PBZ pre-treatment. PBZ treatment may enable sweet potato 'Taoyuan 2' to maintain the balance between the formation and the detoxification of activated oxygen species. Our results also show that under flooding-stress conditions, the level of 'Taoyuan 2' antioxidative system is linked to PBZ treatment. Pre-treating with PBZ may increase levels of various components of antioxidative systems after exposure to different durations of flooding and drainage, thus inducing flooding tolerance. PBZ exhibited the important function of enhancing the restoration of leaf oxidative damage under flooding stress after the pre-application of 0.5 mg/plant. These findings may have greater significance for farming in frequently flooded areas.
本实验的目的是研究在淹水胁迫下甘薯叶片中抗氧化剂和抗氧化酶的变化，以及淹水前24小时多效唑（PBZ）处理对其的影响。甘薯品种“桃源2号”分别用0和0.5毫克/株的PBZ处理，然后在非淹水和淹水胁迫条件下分别处理0、1、3和5天，随后进行2天的排水期。该研究采用析因试验，在网室内完全随机区组设计，重复三次。不同抗氧化系统的植株对淹水胁迫的反应因淹水时间和随后的排水期不同而有所差异。在淹水的不同天数观察到抗氧化剂和抗氧化酶水平的增加，使甘薯叶片的耐淹性得到提高。与非淹水条件相比，连续淹水5天随后排水期，叶片中的谷胱甘肽还原酶活性显著增强。在非淹水条件下，PBZ预处理可调节并提高叶片的抗氧化系统。PBZ处理可能使甘薯“桃源2号”维持活性氧形成与解毒之间的平衡。我们的结果还表明，在淹水胁迫条件下，“桃源2号”抗氧化系统的水平与PBZ处理有关。PBZ预处理可能会增加在经历不同淹水和排水时间后抗氧化系统各组分的水平，从而诱导耐淹性。在预先施用0.5毫克/株的PBZ后，PBZ在淹水胁迫下增强叶片氧化损伤恢复方面发挥了重要作用。这些发现可能对常发洪涝地区的农业生产具有更大的意义。
