《植物生理学报》 2017, 53(6): 1087-1096

外源亚精胺对低温胁迫下甜瓜幼苗生长和抗氧化系统的影响

张永平, 许爽, 杨少军, 陆世钧, 陈幼源^*

上海市农业科学院园艺研究所, 上海市设施园艺技术重点实验室, 上海201403

通信作者：陈幼源；E-mail: yy12@saas.sh.cn

摘　要：

以甜瓜(Cumumis melo)品种‘GL-1’为试验材料, 在人工气候箱内采用基质栽培方式, 研究了0.1~2 mmol·L^-1的外源亚精胺(spermidine, Spd)对低温胁迫[昼(12±1)°C/夜(6±1)°C]及恢复下甜瓜幼苗生长和活性氧代谢系统的影响, 以探讨外源Spd调控低温胁迫对甜瓜幼苗伤害的可行性。结果显示: 低温胁迫能显著影响甜瓜幼苗的生长和活性氧代谢系统的相关指标。适宜浓度的外源Spd能不同程度缓解甜瓜幼苗所受低温胁迫伤害, 并以1 mmol·L^-1 Spd处理效果最好, 其显著促进了幼苗生长, 提高了超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)、脱氢抗坏血酸还原酶(DHAR)、谷胱甘肽还原酶(GR)等抗氧化酶活性, 同时也提高了还原型抗坏血酸(AsA)、还原型谷胱甘肽(GSH)、可溶性蛋白和脯氨酸含量, 降低了过氧化氢(H₂O₂)和丙二醛(MDA)的积累及超氧阴离子(O₂ ¯· )产生速率。研究表明, 外源Spd缓解甜瓜幼苗低温胁迫伤害具有剂量效应, 以1 mmol·L^-1 Spd效果最好。低温胁迫下, 外源Spd处理可增强甜瓜幼苗抗氧化酶活性, 提高抗氧化剂含量, 维持AsA-GSH循环系统的稳定性, 降低H₂O₂和MDA的积累及O₂ ¯·产生速率, 从而减轻活性氧对甜瓜幼苗的伤害, 保护细胞膜结构的稳定性, 增强抗低温能力。

关键词：外源亚精胺; 甜瓜; 低温胁迫; 植株生长; 抗氧化性

收稿：2017-02-20   修定：2017-03-24

资助：上海市瓜果产业技术体系(沪农科产字[2017]第1号)和上海市科委重点攻关项目(14391900900)。

Effect of exogenous spermidine on the growth and antioxidant system of melon seedlings under low temperature stress

ZHANG Yong-Ping, XU Shuang, YANG Shao-Jun, LU Shi-Jun, CHEN You-Yuan^*

Horticultural Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai Key Laboratory of Protected Horticultural Technology, Shanghai 201403, China

Corresponding author: CHEN You-Yuan; E-mail: yy12@saas.sh.cn

Abstract:

Using substrate culture, we investigated the effects of 0.1–2 mmol·L^-1 exogenous spermidine (Spd) on the growth and reactive oxygen metabolism under low temperature stress [(12±1)°C/(6±1)°C, day/night] and recovery in climate chambers with melon (Cumumis melo) variety ‘GL-1’. The results show that low temperature stress had significant effects on the growth and indexes of reactive oxygen metabolism. The suitable concentration of Spd treatment could alleviate the damage of low temperature in various degree; the best effect was observed in the treatment of 1 mmol·L^-1 Spd, which significantly increased the seedlings growth and the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), dehydroascorbic acid reductase (DHAR) and glutathione reductase (GR), increased the content of reductive-form abscisic acid (AsA), reduced glutathione (GSH), soluble protein and proline, and decreased the accumulation of H₂O₂ and malondialdehyde (MDA), and the production rate of superoxide anion radical (O₂·−). The above results indicate that dosage effect of Spd exists on the alleviation of low temperature stress in melon seedlings, and the best alleviating effect was 1 mmol·L^-1 Spd, which was favorable for the seedlings to maintain the stability of AsA-GSH circulation system, decrease the accumulation of H₂O₂ and MDA, and the production rate of O₂·−, protect the stability of cell membrane structure by promoting antioxidant enzyme activities and antioxidant contents, and thereby reduce the damage of the active oxygen to the melon leaf and enhance the cold resistance.

Key words: exogenous spermidine; melon; low temperature stress; seedling growth; antioxidation