Zn^(2+)胁迫及恢复下番茄幼苗根系中抗氧化系统的动态变化(英文)

DYNAMIC CHANGES IN ANTIOXIDATIVE SYSTEMS IN ROOTS OF TOMATO (LYCOPERSICOM ESCULENTUM MILL.) SEEDLING UNDER ZINC STRESS AND RECOVERY

通过温室水培试验,研究1.0×10-4mol/LZn2+胁迫及解除胁迫对番茄(Lycopersicom esculentum Mill.)幼苗根系中抗氧化系统的动态变化.结果表明,胁迫条件下,番茄根系丙二醛(MDA)和蛋白质含量增加;超氧化物歧化酶(SOD,EC1.15.1.1),过氧化氢酶(CAT,EC1.11.1.6)和谷胱甘肽过氧化物酶(GPX,EC1.11.1.9)活性上升,而过氧化物酶(POD,EC1.11.1.7)活性下降;AsA-GSH循环代谢受影响;抗坏血酸过氧化酶(APX,EC1.11.1.11)活性在胁迫d1、d3上升,随后下降,而谷胱甘肽还原酶(GR,EC1.6.4.2)活性在胁迫1~5d时下降,随后上升;抗坏血酸(AsA)和谷胱甘肽(GSH)含量上升.解除胁迫后,根系中MDA和蛋白质含量随时间延长逐渐减少,接近对照;POD和APX活性增加,而SOD、CAT和GR活性及GSH含量先升高,随后减少;GPX活性和AsA含量却降低;恢复后根系中抗氧化物水平仍然高于对照.依据实验结果,文中讨论了胁迫及恢复过程中植物AsA-GSH循环代谢的作用.

Abstract A solution culture experiment was carried out in greenhouse to study the dynamic changes in antioxidative systems in roots of tomato seedlings （ Lycopersicom esculentum Mill. ） under zinc stress and recovery. The results showed that under stress malonaldehyde （MDA） and protein contents increased, and the activities of superoxide dismutase （ SOD, EC 1.15.1.1 ）, cat- lase （ CAT, EC 1.11.1.6） and glutathione peroxidase （ GPX, EC 1.11.1.9） increased, while guaiacol peroxidase （ POD, EC 1.11.1.7） activity declined. AsA - GSH cycle was affected. Ascorbate peroxidase （ APX, EC 1.11.1.11 ） activity rose in the first three days and decreased then, and glutathione reductase （GR, EC 1.6.4.2） activity decreased in the first five days and increased then, the contents of ascrobate （AsA） and glutathione （GSH） increased as well. After recovery, MDA and pro- tein contents declined to control level. The activities of POD and APX increased, while the activities of SOD, CAT and GR and GSH content increased in the beginning of recovery, and then decreased. GPX activity and AsA content in roots duratively de~ clined. After recovery the activities and contents remained higher than those of controls. According to the results of the experi- ment, the role of AsA -GSH cycle during the stressed and recovering period was discussed in this paper. Fig 3, Ref 16 Keywords tomato （ Lycopersicom esculentum Mill. ） ; zinc ; malonaldehyde ; antioxidative systems ; AsA - GSH cycle CLC Q945.78 ： 5641.201