GSH对低温胁迫下枇杷幼果叶绿体AsA-GSH循环代谢的影响

Effects of GSH on AsA-GSH Circulation Metabolism in Chloroplasts of Young Loquat Fruits Under Low Temperature Stress

以3年生"早钟6号"枇杷容器苗为试材,研究不同质量浓度(100,300,500mg·mL-1)谷胱甘肽(GSH)处理对-3℃条件下枇杷幼果叶绿体AsA-GSH循环代谢的影响及其在抗低温胁迫中的作用。低温胁迫下枇杷幼果叶绿体抗氧化剂还原型谷胱甘肽(GSH)和抗坏血酸(AsA)含量下降,抗坏血酸过氧化物酶(APX)、谷胱甘肽还原酶(GR)、单脱氢抗坏血酸还原酶(MDHAR)和脱氢抗坏血酸还原酶(DHAR)活性受到不同程度的抑制。采用100mg·mL-1的GSH处理可显著提高低温胁迫下枇杷幼果叶绿体GSH,AsA含量以及APX,GR和MDHAR活性,促进AsA-GSH循环,叶绿体清除自由基的能力增强,在枇杷幼果抵抗低温胁迫中发挥作用。

The paper studied the application of reduced glutathione（GSH）in increasing the chilling resistance of young loquat（Eriobotrya japonica cv.Zaozhong No.6）fruits.The container seedling of three-year-old loquat were treated with 100,300 and 500 mg·L-1 of GSH to investigate the effects of exogenous GSH on AsA-GSH circulation metabolism in chloroplasts of young loquat fruits under low temperature stress,and its effects on the resistance to low temperature stress.The results showed that the contents of reduced glutathione（GSH）and ascorbic acid（AsA）in chloroplasts decreased and the activities of ascorbate peroxidase（APX,EC 1.11.1.11）,glutathione reductase（GR,EC 1.6.4.2）,dehydroascorbate reductase（DHAR,EC 1.8.5.1）and monodehydroascorbate reductase（MDHAR,EC 1.6.5.4）were also inhibited decreased when the young loquat fruits were under low temperature stress.The treatment with 100 mg·L-1 of GSH on young loquat fruits could significantly increase the GSH,AsA contents and APX,GR,MDHAR activities.Furthermore,the treatment promoted AsA-GSH circulation metabolism,and improved the ability of free radicals to scavenge in chloroplasts.The results demonstrated that exogenous GSH played a role in the low temperature stress resistance of young loquat fruits.