NO对损伤诱导的豌豆幼苗叶片抗氧化系统的影响

为了明确损伤后豌豆幼苗叶片内NO产生的途径及NO对其诱导的抗氧化系统的作用，以豌豆幼苗为试材，研究损伤胁迫下其内源NO含量、NR和NOS活性的变化，以及只有NO供体SNP处理和NO清除剂PTIO、NOS抑制剂L-NAME、NR抑制剂NaN₃喷施后损伤处理过24 h 时对豌豆幼苗叶片内H₂O₂和O₂ ^-·含量变化及对抗氧化酶SOD、POD、CAT、APX等的活性影响。结果表明，损伤处理后0~60 h 内豌豆幼苗叶片内NO含量呈双峰曲线；其中损伤处理早期（第1 峰值）NO的主要来源是NOS酶促途径，而后期（第2 峰值）NO的主要来源是NR酶促途径；损伤处理24 h 豌豆幼苗叶片内NO含量最高，此时H₂O₂和O₂ ^-·含量接近对照水平，而SOD、POD、CAT、APX等的活性显著高于对照，NO供体SNP处理时有类似的结果，NO清除剂PTIO 处理后H₂O₂和O₂ ^-·含量升高，SOD、POD、CAT、APX等的活性降低。以上研究结果表明，NO可能通过增强保护酶的活性来降低损伤诱导的膜脂过氧化程度。

Effects of Nitric Oxide on Wounding Induction of Pea Seedling Leaves Antioxidant System

In this experiment pea seedlings were used to study its endogenous NO contention under wounding stress, the activity changes of NR and NOS activity, as well as the activity influence to antioxidant enzymes SOD, POD, CAT and APX and the contention changes of H2O2 and O2- in the leaves of pea seedlings after 24h when spraying processed with SNP (donor of NO), PTIO (scavenger of NO), L-NAME (inhibitors of NOS) and NaN3 (inhibitors of NR) respectively.Results show that NO contention in the pea seedling leaves present a bimodal curve between 0 and 60 hours after the wounding treatment. The main source of NO is NOS enzymatic way when the earlier period of wounding process (the first peak value);But the main source of NO is NR enzymatic way when the later period of wounding process (the second peak value);during the first 24h,pea seedling leaf NO contention reach a highest, and the contention of H2O2 and O2- close to the control level, while the activity of SOD, POD, CAT and APX is higher than control significantly.When treated with SNP, it have a similar result.After the treatment with PTIO, the contention of H2O2 and O2- increased,and the activity of SOD, POD, CAT and APX decreased.Conclusion of the research results shows that NO may reduce the membrane lipid peroxidation induced by wounding degree through enhancing the activity of protective enzyme .