钙调素拮抗剂W7对低氧胁迫下黄瓜根系抗氧化系统的影响

以黄瓜为材料采用营养液栽培法研究了低氧胁迫下钙调素拮抗剂W7对根系抗氧化系统的影响.结果表明:用50mmol·L-1W7预处理24h后,进行低氧胁迫处理,黄瓜根系的超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)、谷胱甘肽还原酶(GR)的活性降低,而O2产生速率、H2O2和丙二醛(MDA)含量均高于低氧胁迫处理.钙调素拮抗剂W7预处理后,导致黄瓜根系内活性氧含量升高和保护酶活性下降,从而降低黄瓜对低氧胁迫的抵抗能力,减缓了根系生长,表明Ca2 ·CaM信号系统的诱导和调控对缓解低氧胁迫具有重要作用.

Effect of calmodulin antagonist W7 on antioxidant systems of roots of cucumber seedlings under hypoxia stress

The effect of calmodulin antagonist W7 on antioxidant systems of roots of cucumber seedlings under hypoxia stress was studied in hydroponics culture. Results show that pretreated seedlings with calmodulin antagonist W7 under hypoxia stress have lower SOD, POD, CAT, APX and GR activities, and higher production rate of O₂^-, MDA and H₂O₂ contents compared with hypoxia stress treatment without calmodulin antagonist W7 pretreatment. This indicates that calmodulin antagonist W7 pretreatment can restrain Ca²⁺·CaM signal transduction, leading to increase in reactive oxygen content and decrease in activity of certain antioxidants, subsequently reducing resistance of cucumber seedlings to hypoxia stress, hence stunted roots. The experiment shows that Ca²⁺·CaM signal system plays an important regulating role in alleviating hypoxia stress in roots of cucumber seedlings.