【摘要】 用硝普钠(SNP,NO供体)和ABA处理玉米幼苗,结果显示,ABA和SNP均增强了玉米叶片中抗氧化酶SOD、CAT、GR和APX的活性;激光共聚焦显微检测显示,ABA能够诱导叶片中NO的合成;NO清除剂PTIO和合成抑制剂L-NAME预处理阻断了ABA诱导的抗氧化酶活性的上升及NO的合成。对不同亚细胞区室的研究显示,ABA和NO对质外体和叶绿体中的抗氧化酶系统均表现出诱导效应,而PTIO和L-NAME阻断了这种诱导。上述结果表明,在玉米叶片中,NO介导了ABA的信号转导,诱导叶绿体和质外体中的抗氧化酶系统协同作用,共同提高了叶片的抗氧化防护能力。更多还原

【Abstract】 The role of nitric oxide(NO)in abscisic acid(ABA)-induced antioxidant defense in leaves of maize(Zea mays)plants was investigated.Treatments with SNP(sodium nitroprusside,NO donor)or ABA enhanced the activities of chloroplastic,apoplastic and total superxide dismutase(SOD),catalase(CAT),glutathione reductase(GR)and ascorbate peroxidase(APX)in leaves of maize plants.Such enhancements were blocked by pretreatment with NO scavenger PTIO(2-phenyl-4,4,5,5-tetramethyl-imidazoline-1-oxyl-3-oxyde)or NO synthesis inhibitor L-NAME(N~G-nitro-L-arginine methyl ester).ABA-induced NO production in maiza leaves was examined by laser scanning cofocal microscopy.Pretreatment with NO scavenger PTIO or NO synthesis inhibitor L-NAME arrested the ABA-induced NO production.These results suggest that NO is involved in the signaling transduction of ABA and could coordinate the activities of antioxidant enzymes in different subcellular compartments.更多还原