摘要
以水稻品种‘浙辐802’为材料,采用水培法研究铝毒下外源NO对幼苗根系生长、活性氧产生和抗氧化酶活性的影响,探讨外源NO提高水稻耐铝性的生理生化机制。结果显示:(1)0.05mmol/L Al显著抑制水稻根系生长,促使根尖Al、胼胝质、过氧化氢(H2O2)和超氧阴离子自由基(O-·2)含量显著增加;而外源0.1mmol/L的NO供体亚硝基铁氰化钠(sodium nitroprusside,SNP)预处理能使铝毒下水稻幼苗根相对伸长率及根尖NO含量分别增加34.96%和12.86%,根尖Al和相对胼胝质含量分别下降83.04%和31.93%,表明NO可部分缓解铝毒害,且这种作用与内源NO含量变化有关。(2)外源NO同时使铝毒下水稻幼苗根尖H2O2和O-·2含量分别下降15.43%和12.93%,使超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性显著上升,且外源NO的该种作用可以被0.075mmol/L NO清除剂(carboxy-PTIO,cPTIO)所逆转。研究表明,外源NO在调节活性氧代谢以维持细胞膜结构稳定,进而有效减轻Al对水稻根系的损伤上起着重要作用。
To verify the physiological mechanism of exogenous nitric oxide （NO） on ameliorating AI toxicity in rice,we planted cultivar ‘Zhefu 802＇ in hydroponic solutions,and then detected the reactive oxygen spe- cies and antioxidase activity. The results showed that. （1）0. 05 mmol/L Al significantly inhibited root growth,caused Al and callose accumulation in root tips, and increased the contents of reactive hydrogen peroxide （H2O2） and superoxide anion freebase （O2）. Pretreatment the rice seedlings were applied with 0.1 mmol/L sodium nitroprusside in the presence of Al （SNP,NO donor） increased relative root elongation and NO content by 34. 96% and 12. 86%, respectively,reduced Al and eallose contents by 83. 04% and 31.93% ,indicating that NO partially alleviated Al toxicity which might be caused bv the rising levels of en-dogenous NO. （2）The exogenous NO decreased HzOz and O2 contents by 15. 43% and 12.93%,respec- tively, and significantly enhanced SOD,POD and CAT activities in rice root tips. In contrary,the ameliora- ting effect was reversed by the addition of NO scavenger （carboxy-PTIO, cPTIO） in the presence of Al. These results showed that exogenous NO played an important role in maintaining cell membrane structure stability by regulating reactive oxygen metabolism under A1 toxicity, thereby reducing the Al damage to rice roots.
出处
《西北植物学报》
CAS
CSCD
北大核心
2014年第3期536-542,共7页
Acta Botanica Boreali-Occidentalia Sinica
基金
国家自然科学基金(31101599)
浙江省自然科学基金(Y3110561)
关键词
水稻
铝毒
N0
活性氧
抗氧化酶
rice
aluminum toxicity
nitric oxide ~ reactive oxygen
antioxidase
