油菜素内酯对Ca(NO_3)_2胁迫下黄瓜叶绿体AsA-GSH循环及叶黄素稳态的影响  

The Regulation of 24-epibrassinolide on AsA-GSH Cycle and Xanthophylls Homeostasis in Chloroplast of Cucumber Under Ca(NO_3)_2 Stress

作　　者：袁凌云[1,2] 汪承刚[1,2] 黄兴学 汤玲[1] 侯金锋[1] 刘凡[1] 汪龙[1] 朱世东[1,2] 

机构地区：[1]安徽农业大学园艺学院,合肥230036 [2]皖江蔬菜产业技术研究院,安徽马鞍山238200 [3]安徽和县台湾农民创业园管委会,安徽马鞍山238200

出　　处：《园艺学报》2017年第5期881-890,共10页Acta Horticulturae Sinica

基　　金：安徽高校自然科学研究项目(KJ2017ZD15);安徽省自然科学基金项目(1608085QC48)

摘　　要：研究了外源油菜素内酯(24–表油菜素内酯,EBL)对Ca(NO_3)_2胁迫下黄瓜光合器官的调控作用。在Ca(NO_3)_2胁迫条件下,外源EBL显著提高了叶绿体中还原型抗坏血酸和谷胱甘肽的含量,分别是对照的2.44倍和1.40倍。AsA-GSH循环中的抗坏血酸过氧化物酶(APX)和谷胱甘肽还原酶(GR)活性比胁迫处理增加了36.27%和105.83%。外源EBL的施用显著增加了紫黄质(V)、玉米黄质(Z)和总叶黄素含量,减少了花药黄质(A)的积累,叶黄素脱环氧化态比胁迫处理增加了9.60%。胁迫条件下,EBL显著提高了植株叶片的非光化学猝灭(NPQ),缓解了PSⅡ实际光化学效率(Φ_(PSⅡ))的下降。EBL处理后,叶绿体膜多种不饱和脂肪酸的水平比对照明显增加。试验结果表明,外源EBL能够通过调控AsA-GSH循环及热耗散,增强叶绿体抗氧化能力,从而抵抗Ca(NO_3)_2胁迫。The objective of this study was to identify the regulation effects of exogenous brassinosteroids（BRs）on photosynthetic apparatus of cucumber（Cucumis sativus L.‘Jinyou 4’）under Ca（NO3）2（80 mmol · L^-1）stress. Exogenous 24-epibrassinolide（EBL）markedly increased the reduced ascorbate（AsA）and glutatione（GSH）levels in chloroplast,which were 2.44-fold and 1.40-fold to control. Enzymes activities of APX and GR in AsA-GSH cycle were enhanced by 36.27% and 105.83% respectively,compared to stress treatment. Application of EBL also changed the levels of xanthophyll cycle components,increasing V,Z and total xanthophylls levels and decreasing A level. The de-epoxidation state（DEPS）of xanthophyll cycle by EBL was increased by 9.60% compared to Ca（NO3）2-stressed plant. Under Ca（NO3）2 stress,EBL enhanced the NPQ and alleviated the decrease of ΦPSⅡ. EBL resulted in increases of unsaturated FAs levels,which was favored to the lipid membrane fluidity. These results strongly suggested that exogenous EBL is capable of protecting the chloroplast function through regulating the AsA-GSH cycle and heat dissipation capacity under Ca（NO3）2 stress.

关 键 词：黄瓜 24–表油菜素内酯 叶黄素循环 非光化学猝灭 AsA-GSH循环 脂肪酸 叶绿体 

分 类 号：S642.2[农业科学—蔬菜学]