抗坏血酸提高月季切花失水胁迫耐性与增加APX活性的关系

 以‘Samantha’品种为试材, 确定了适宜的抗坏血酸(AsA) 预处理浓度, 探讨了AsA和抗坏血酸过氧化物酶(APX) 抑制剂(对氨基酚, β-aminophenol) 预处理对花瓣中相对电导率、AsA含量以及APX活性的影响。与未经失水胁迫的切花月季相比较, 失水胁迫处理抑制切花的开放进程, 缩短了瓶插寿命。AsA 1 000 mg·L ^{- 1}预处理可有效地改善花朵的开放状况, 显著降低花瓣中相对电导率的增加, 明显提高花瓣中AsA的含量和APX活性。500 mg·L ^{- 1} β-aminophenol预处理则起到相反的效应。结果说明,AsA对‘Samantha’月季切花失水胁迫耐性的改善与花瓣中APX活性的提高相联系。

Ascorbate Acid Increases Tolerance to Water Deficit Stress in Flowers of Cut Roses (Rosa hybrida L. ) Caused by Enhanced Ascorbate Peroxidase Activity

Pretreatmentwith ascorbic acid (AsA) increased tolerance of the flowers of cut roses to water deficit stress. The op timum p retreatment concentrations of AsA and β-aminophenol ( an inhibitor of ascorbate peroxidase, APX) were determined in cut rose‘Samantha’ flowers. Water deficit stress inhibited flower opening and reduced vase life. Pretreatment of 1 000 mg·L ^{- 1} AsA improved markedly the flower opening, delayed significantly the increase in relative electric conductivity, and increased obviously AsA content andAPX activity. The negative resultswere obtained when 500 mg·L ^{- 1} β-aminophenol pretreatment was used.These results indicate that the improvement of AsA on tolerance to water deficit stress may be related to enhanced APX activity in petals of cut roses.