作 者 ：张波, 梁永超, 褚贵新, 危常州, 冶军, 马腾飞, 李志强
期 刊 ：植物营养与肥料学报 2010年 16卷 6期 页码：1387-1393
Keywords:photosynthesis, omethoate, antioxidant enzymes, wheat,
摘 要 ：通过溶液培养研究了不同浓度（0、0.1、1.0、5.0和10.0 g/L）氧乐果处理后小麦幼苗叶绿素含量、类胡萝卜素含量、可溶性糖含量及保护酶活性的动态变化。结果表明: 在氧乐果胁迫下，高浓度的氧乐果（5.0和10.0 g/L）处理显著降低了小麦幼苗的叶绿素含量和类胡萝卜素含量，且随着处理时间的延长其差异尤为显著; 小麦叶片中可溶性糖含量随着氧乐果浓度和处理天数的增加而显著增加。超氧化物歧化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（CAT）的活性均先上升后下降; 抗坏血酸过氧化物酶（APX）和谷胱甘肽还原酶（GR）活性在0.1 g/L氧乐果处理的第1d时略有上升，然后下降。小麦响应氧乐果胁迫并上调SOD、POD、CAT等保护酶的活性和可溶性糖的含量，降低叶片光合作用，籍此维持小麦免受低浓度氧乐果的胁迫以维持小麦的正常生长; 但高浓度氧乐果处理对小麦根系产生了明显的毒害作用，致使5.0 g/L氧乐果胁迫的小麦根系SOD、POD、CAT活性显著下降。APX和GR可能在低浓度氧乐果处理初期起主要保护作用，而在高浓度氧乐果胁迫下则受到明显抑制作用。
Abstract:We investigated chlorophyll, carotenoid, and soluble sugar contents as well as the mechanical details of antioxidative defence responses in wheat (Triticum aestivum L. cv. Xindong No. 17) seedlings experimentally treated with varying levels of omethoate. The objectives of the present study are to better understand physiological and biochemical responses to omethoate in wheat. For this, wheat seedlings were grown hydroponically for two weeks and subsequently exposed to 0 (control), 0.1, 1.0, 5.0 and 10.0 g/L of omethoate, respectively. Plant samples were collected at 1, 3, 5 and 7 days after treatment, respectively, for analysis of the physiological parameters selected. Results showed that chlorophyll content as well as carotenoid content was decreased with increasing concentration of omethoate, especially as the experiment was progressed. In contrast, soluble sugar content was raised with increasing concentration of omethoate, especially as the experiment continued. The activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) were increased in the treatments with low concentrations but sharply decreased in the treatments with high concentrations. Moreover, the activities of ascorbate peroxidase (APX) and glutathione reductase (GR) were increased at 0.1 g/L of omethoate on day 1 and then decreased as the concentration of omethoate was raised and the experiment was progressed. In conclusion, wheat could tolerate omethoate stress and could grow normally at low concentrations of omethoate. The possible mechanisms involved might be attributed to higher activities of SOD, POD and CAT, higher soluble sugar content and lower photosynthetic activity, resulting in lower oxidative damage. However, the activities of SOD, POD and CAT were inhibited by the treatments with high concentrations of omethoate. Besides, the activities of APX and GR were promoted in the treatment with extremely low concentrations of omethoate to protect plants form oxidative damage. However, wheat growth was significantly inhibited by the treatments with high concentrations of omethoate.
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