曹碧珍

摘 要：采用不同質量浓度（100、150、175 mg·L-1）的5氨基乙酰丙酸（ALA）处理低温胁迫下3年生的早钟6号枇杷容器苗，以喷施清水为对照（CK），在-3℃下低温胁迫处理3 h，比较分析不同处理对枇杷叶片过氧化氢（H2O2）、抗坏血酸（AsA）和还原型谷胱甘肽（GSH）含量及脱氢抗坏血酸还原酶（DHAR）、谷胱甘肽还原酶（GR）、单脱氢抗坏血酸还原酶（MDHAR）和抗坏血酸过氧化物酶（APX）活性的影响。结果表明：与CK相比，外源ALA处理的枇杷叶片显著促进了叶片中抗坏血酸（AsA）和还原型谷胱甘肽（GSH）含量的增加及脱氢抗坏血酸还原酶（DHAR）、单脱氢抗坏血酸还原酶（MDHAR）、谷胱甘肽还原酶（GR）和抗坏血酸过氧化物酶（APX）活性的上升，降低过氧化氢（H2O2）含量。说明外源ALA处理促进了低温胁迫下枇杷叶片AsA-GSH的有效循环，增强细胞的抗氧化性，提高枇杷幼苗的耐寒性。说明适当外源5氨基乙酰丙酸（ALA）处理能够调控枇杷叶片中AsAGSH循环，进而提高枇杷叶片的抗寒性，减轻枇杷在低温胁迫下的损伤，其中以175 mg·L-1ALA处理效果最显著。

关键词：5氨基乙酰丙酸;枇杷;低温胁迫;AsAGSH循环

中图分类号：S 667.3   文献标志码：A   文章编号：0253-2301（2021）11-0007-07

DOI： 10.13651/j.cnki.fjnykj.2021.11.002

Effects of Exogenous 5aminolevulinic Acid （ALA） on the AsA-GSHCirculation in Loquat Leaves Under the Stress of Low Temperature

CAO Bi-zhen

（Putian Xialin Sub-District Office of People′s Government of Chengxiang District， Putian， Fujian 351100， China）

Abstract： Different concentrations of 5aminolevulinic acid （ALA） （100， 150， 175 mg·L-1） were used to treat the three-year-old Zaozhong No.6 loquat container seedlings under the stress of low temperature. With spraying water as the control （CK）， the effects of different treatments on the contents of hydrogen peroxide （H2O2）， ascorbic acid （AsA） and reductive glutathione （GSH） and the activities of dehydroascorbate reductase （DHAR）， glutathione reductase （GR）， monodehydroascorbate reductase （MDHAR） and ascorbate peroxidase （APX） in the leaves of loquat were compared and analyzed when applying the low temperature stress at -3℃ for 3 h. The results showed that： compared with CK， the exogenous treatment with ALA on the leaves of loquat significantly promoted the increase of the contents of ascorbic acid （AsA） and reductive glutathione （GSH）， and the activities of dehydroascorbate reductase （DHAR）， monodehydroascorbate reductase （MDHAR）， glutathione reductase （GR） and ascorbate peroxidase （APX） in loquat leaves， but reduced the content of hydrogen peroxide （H2O2）. This indicated that the exogenous treatment with ALA promoted the effective circulation of AsA-GSH in loquat leaves under the stress of low temperature， enhanced the antioxidant activities of cells， and improved the cold tolerance of loquat seedlings. Therefore， the appropriate exogenous treatment with 5aminolevulinic acid （ALA） could regulate the AsA-GSH circulation in loquat leaves， thus improving the cold resistance of loquat leaves and reducing the damage of loquat under the stress of low temperature， among which the treatment with 175 mg·L-1 ALA had the most significant effect.

Key words： 5aminolevulinic acid; Loquat; Low temperature stress; AsA-GSH circulation

枇杷Eriobotrya japonica Lindl.是一种典型的亚热带常绿果树，好湿润、温和的气候条件。枇杷品种根据生态类型可分为耐寒性较强的温带型品种和耐寒性较弱的热带型品种，而低温胁迫则是热带型枇杷品种生长的关键性因子。近些年来，我国南方山地枇杷产区都有出现不同程度的冻害，福建主要以早钟6号枇杷（Eriobotrya japonica Lindl.cv.Zaozhong No.6）受冷害最为严重[1]。探讨枇杷抗冻性的调控机制对于减少因冷害造成的损失具有重要意义。……