【摘要】 10μmol/L甲基紫精（MV）预处理水稻幼苗可明显提高其抗冷力,但这种功效可被钙的螯合剂EGTA（10mmol/L）和钙调素（CaM）的抑制剂氯丙嗪（CPZ,0.5mmol/L）所抑制。MV预处理提高了幼苗质膜、液泡膜Ca²⁺-ATP酶活性,同时也有提高质膜Fe（CN）₆^3-还原速率和这些活性的冷适应性,但这些效果均可被EGTA和CPZ所抑制。离体条件下,膜微囊的Ca²⁺-ATP酶活性对H₂O₂、O₂⁷、-OH敏感。结果显示,MV预处理提高幼苗的抗冷力可能是通过钙信使介导起作用的,钙信使或CaM可能刺激了质膜、液泡膜Ca²⁺-ATP酶活性;而该预处理有增加质膜、液泡膜Ca²⁺-ATP酶的冷稳定性则可能与该处理有提高细胞抗氧化能力、稳定冷胁迫下细胞膜系统结构有关。更多还原

【Abstract】 The cold tolerance of rice (Oryza saliva L.) seedlings could be markedly improved by mild oxidative pretreatment (10 μmol/L methyl viologen (MV). The enhancement of chilling resistance induced by MV pretreatment could be inhibited by Ca2 +-chelate ethyleneglycol-bis-(β-aminoethylether) N,N-tetraacetic acid (EGTA, 10 mmol/L) and the calmodulin inhibitor chlorpro-mazine (CPZ, 0.5 mmol/L). The Ca2+-ATPase activity of root plasmolemma and tonoplast membrane as well as the Fe(CN)63- reduction of plasmolemma were also enhanced by MV pretreatment. However, the above MV pretreatment effect could be inhibited by EGTA and CPZ, respectively. In vitro, Ca2+-ATPase activities in the two types of membrane vesicles were reduced by reactive oxygen species (H2O2, O2-, OH). Results indicated that the enhancement of chilling resistance in rice seedlings with MV pretreatment was likely related to the effective activation of Ca2+-ATPase induced by calcium messenger of CaM, and the improved cold tolerance of the activities might be associated with the augmentation of cellular membrane protective ability caused by the MV pretreatment.更多还原