《植物生理学报》 2015, 51(6): 916-920

超低温保存后玉兰花粉的氧化应激和细胞凋亡研究

徐瑾^1,2, 石印¹, 刘芊¹, 刘燕^1,*, 贾梦雪¹, 李秉玲¹

¹花卉种质创新与分子育种北京市重点实验室, 国家花卉工程技术研究中心, 城乡生态环境北京实验室, 北京林业大学园林学院, 北京100083; ²广州大学建筑与城市规划学院, 广州510006

通信作者：刘燕；E-mail: chblyan@163.com；Tel: 010-62336062

摘　要：

为了揭示花粉超低温保存的生理机制, 本研究以玉兰花粉作为试验材料, 对花粉超低温保存前后与氧化应激和细胞凋亡相关的指标进行测定。结果显示, 活性氧水平和丙二醛含量在花粉超低温保存前后没有显著变化, 而质膜相对透性在超低温保存后显著提高, 说明脂质过氧化不是造成细胞膜通透性增强的直接原因。超低温保存后过氧化氢酶活性显著升高, 而抗坏血酸含量显著下降, 说明超低温保存引起了玉兰花粉细胞内抗氧化防御系统的显著变化, 细胞通过氧化/抗氧化系统的自我调节取得了新的平衡, 因而使活性氧的水平在保存前后维持了稳定, 并未诱导氧化应激的发生。对磷脂酰丝氨酸的外化水平和DNA片段化程度的测定表明, 超低温保存并未引起细胞凋亡现象的发生。这可能是维持超低温保存后玉兰花粉高生活力的根本原因。

关键词：花粉; 超低温保存; 氧化应激; 细胞凋亡

收稿：2015-01-29   修定：2015-04-28

资助：国家自然科学基金(31370693)。

Oxidative Stress and/or Apoptosis of Magnolia denudata Pollen after Cryopreservation

XU Jin^1,2, SHI Yin¹, LIU Qian¹, LIU Yan^1,*, JIA Meng-Xue¹, LI Bing-Ling¹

¹Beijing Key Laboratory of Ornamental Plants Germplasm Innovation & Molecular Breeding, National Engineering Research Center for Floriculture, Beijing Laboratory of Urban and Rural Ecological Environment, College of Landscape Architecture, Beijing Forestry University, Beijing 100083, China; ²College of Architecture & Urban Planning, Guangzhou University, Guangzhou 510006, China

Corresponding author: LIU Yan; E-mail: chblyan@163.com; Tel: 010-62336062

Abstract:

In order to reveal the physiological mechanism of pollen cryopreservation, pollen of Magnolia denudata was chosen and the oxidative stress and apoptosis-related indicators were measured. The results showed that there was no significant difference on reactive oxygen species generation and malonic dialdehyde content, whereas significantly increase was observed on relative conductivity, which indicated that lipid peroxidation was not a direct cause for enhanced membrane permeability. Significant increase on catalase activity and obvious decrease on ascorbic acid content were discovered, which suggested that cryopreservation had caused a significant change in antioxidant defense system of the magnolia pollen cell and a new balance had achieved via self-regulation of oxidant/antioxidants system, resulted in nonsignificant change on reactive oxygen species generation and no oxidative stress occurred. The results on phosphatidylserine externalization and DNA ladder measurements revel that apoptosis did not exist in magnolia pollen cryopreservation. These may be the reasons why high germination level of pollen was remained after cryopreservation.

Key words: pollen; cryopreservation; oxidative stress; apoptosis