摘要： 以抗冷性不同的2个黄瓜(Cucumis sativus L.)品种461(冷敏型)和407(耐冷型)为试材,研究了不同浓度(0.25,0.50,1.00,1.50,2.00 mmol/L)水杨酸预处理对黄瓜苗期生理特性及CATmRNA基因表达量的影响。结果表明:适宜浓度的SA预处理可以提高两个黄瓜品种的抗氧化酶超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性;叶绿素原初光能转换效率(Fv/Fm)与对照相比有不同程度的提高;Northern杂交分析显示,1.00mmol/L水杨酸能够诱导CATmRNA表达量的上升,与CAT酶活性升高的趋势是一致的。这些结果说明水杨酸预处理可以通过提高抗氧化酶的活性和减轻光抑制来提高黄瓜幼苗的低温耐受性,其中1.00 mmol/L水杨酸处理效果较好。

关键词: 低温胁迫, 水杨酸, 抗氧化酶, Fv/Fm, CATmRNA, 黄瓜

Abstract: Two different ecotypes cultivars cv.461 and 407 of cucumber were used under the cold stress ( ( 6 ±1) ℃, 72 h ) and spraying concentrations of salicylic acid( SA) were 0.25, 0.50, 1.00, 1.50, 2.00 mmol/L respectively, to study the effect of SA pretreatment on physiological characteristic and the expression of CATmRNA.The results were as follows: Spraying suitable SA can increased the activity of antioxidases( SOD,CAT and POD); The ratio of variable to maximal fluorescence( Fv/Fm) in the SA-pretreated plants was higher than those control.Northern hybridization blot analysis suggested the expression of the CAT gene in 1.0 mmol/L SA-pretreated plants was higher than control,which was the same as that of CAT activities.It is seen that SA pretreatment can increase chilling tolerance in cucumber seedling by regulating antioxidases activities and the ratio of variable to maximal fluorescence, 1.00 mmol/L SA pretreatment was more effective．

Key words: Chilling stress, Salicylic acid, Antioxidases, Fv/Fm, CATmRNA, Cucumber

中图分类号: 

• S642.2