外源ALA对低温胁迫下巴西蕉幼苗抗冷性的影响  

Effect of exogenous ALA on chilling resistance of Brazil banana seedlings under low temperature stress

作　　者：黄芳 李茂富[1,2] 汪良驹[2] 李绍鹏[1] 

机构地区：[1]热带园艺植物种质资源与遗传改良教育部重点实验室/海南大学园艺园林学院,海口571737 [2]南京农业大学园艺学院,南京210095

出　　处：《南方农业学报》2012年第7期918-923,共6页Journal of Southern Agriculture

基　　金：国家自然科学基金项目(30860170);海南大学青年基金资助项目(qnjj1160)

摘　　要：【目的】探讨ALA对香蕉幼苗抗冷性的生理影响及冷害机制,为ALA调节香蕉抗冷性提供科学依据。【方法】以巴西蕉幼苗为材料,设清水常温(CK1)和清水低温(CK2)为对照,喷施1mg/LALA后置于人工气候箱中(7℃)低温胁迫12、24、36、48h,期间取样测定叶片质膜透性、叶绿素、MDA、可溶性蛋白、脯氨酸以及SOD、POD酶活性等。【结果】与低温对照相比,在低温胁迫期内,外源ALA处理的叶片叶绿素含量、SOD和POD活性、脯氨酸和可溶性蛋白质含量均明显提高,质膜透性、MDA含量和O2-产生速率则有所降低;当低温胁迫36h后,外源ALA处理的叶片叶绿素含量、SOD、POD酶活性分别提高了90.6%、11.7%、58.4%,O2-产生速率、质膜透性、MDA含量降低了85.3%、27.6%、37.1%。【结论】低温胁迫下,外源ALA可提高叶片SOD、POD活性,降低O2-产生速率,减小质膜透性,同时还可增加脯氨酸和可溶性蛋白的积累,维持叶绿素的稳定性,从而提高巴西蕉幼苗的抗冷性。[Objective]The current study was conducted to investigate the physiological effects and chilling injury mechanism of 5-aminolevulinic acid （ALA） on banana seedlings to provide basis for applying ALA in regulating chilling-resistance of banana seedling. [Method]After being sprayed with 1 mg/L ALA, Brazil banana seedlings were placed in an artificial climate box at low temperature stress（7℃） for 12, 24, 36 and 48 h, respectively Such parameters as plasmamembrane permeability, contents of chlorophyll （Chl.）, MDA, soluble proteins and proline, SOD and POD activities of banana leaves were investigated during stress period, normal temperature, and low temperature stress of water were set as CK1 and CK2, respectively. [Result]Compared to CK2, under low temperature stress, Chl. content, activities of SOD and POD, contents of proline and soluble proteins in Brazil banana increased obviously, while plasmamembrane permeability, MDA content and generation rate of superoxide free radical（O2-） decreased. After 36 h stress, Chl. content, activities of SOD and POD in leaves increased by 90.6, 11.7 and 58.4%, respectively, while generation rate of O2-, plasmamembrane permeability and MDA content decreased by 85.3, 27.6 and 37.1%, respectively. [Conclusion]Under low-temperature stress, exogenous ALA can improve cold-resistance of Brazil banana seedlings by enhancing SOD and POD activities, reducing generation rate of O2-and plasmamembrane permeability, as well as increasing accumulation of proline and soluble protein and maintaining the stability of chlorophyll in leaves.

关 键 词：巴西蕉 低温胁迫 ALA 抗冷性 生理机制 

分 类 号：S668.1[农业科学—果树学]