《植物生理学报》 2014, 50(2): 171-177

外源水杨酸对低温下杏花抗氧化酶和CBF转录因子表达的影响

张俊环, 王玉柱∗, 孙浩元, 杨丽, 姜凤超

北京市农林科学院林业果树研究所, 北京100093

通信作者：姜凤超；E-mail: chinabjwyz@sohu.com；Tel: 010-82592521

摘　要：

为探讨水杨酸(SA)对杏花抗寒性的影响机制, 以早熟品种‘骆驼黄’杏的显蕾期花枝为试材, 分析–2 ℃的低温下适宜浓度SA及其抑制剂ABT和PAC对杏花MDA、抗氧化酶和CBF转录因子的影响。结果表明, –2 ℃低温条件下, 对照和2个SA抑制剂处理的杏花细胞膜系统均受到严重伤害, CAT、POD和SOD等抗氧化酶活性降低, MDA含量明显升高。而SA预处理的杏花在低温胁迫期间抗氧化酶活性增强, MDA含量比对照和抑制剂处理的有明显降低且相对稳定。通过荧光定量检测CBF转录因子的表达水平, 表明SA能诱导杏花CBF基因的表达, 尤其在低温处理3 h时, SA预处理的杏花中CBF的表达量明显高于对照和SA抑制剂处理。由此认为, 适宜浓度的外源SA可能是通过调控低温下杏花中CBF转录因子的表达、增强细胞的抗氧化酶活性, 减轻低温造成的膜脂过氧化伤害, 从而在一定程度上增强了杏花的抗寒性。

关键词：杏花; 抗氧化酶; CBF; 低温; 水杨酸

收稿：2013-09-16   修定：2014-01-08

资助：北京市新星计划(2009B27)和北京市自然基金(6122011)

Effects of Exogenous Salicylic Acid on Antioxidant Enzymes and CBF Transcription Factor in Apricot (Prunus armeniaca L.) Flowers under Chilling Stress

ZHANG Jun-Huan, WANG Yu-Zhu∗, SUN Hao-Yuan, YANG Li, JIANG Feng-Chao

Institute of Forestry and Pomology, Beijing Academy of Agriculture and Forestry Science, Beijing 100093, China

Corresponding author: JIANG Feng-Chao; E-mail: chinabjwyz@sohu.com; Tel: 010-82592521

Abstract:

In order to explore the mechanism of exogenous salicylic acid (SA) induced chilling resistance of apricot flowers, the twigs with flower-buds of apricot plant (Prunus armeniaca L. cv. ‘Luotuohuang’) were selected as experimental materials. The levels of MDA, antioxidant enzymes and the expression of CBF gene were investigated in apricot flowers during –2 ℃ chilling stress with pretreated with H₂O, 0.1 mmol·L^-1 SA and SA inhibitors (ABT and PAC), respectively. The results showed that pretreatments with H₂O, ABT and PAC decreased the activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), and increased the MDA content during chilling stress. In contrast, 0.1 mmol·L^-1 SA pretreatment enabled apricot flowers to maintain higher activities of these three enzymes and a lower level of MDA to weaken oxidative injury induced by chilling temperature. The real-time RT-PCR analysis indicated that the expression of CBF gene could be induced by SA and the level of CBF was much higher than that in pretreatments with H₂O, ABT and PAC, especially under chilling stress for 3 h. However, the CBF expression induced by SA was weakened with the chilling time prolonging. Taken together, it was considered that the suitable exogenous SA (0.1 mmol·L^-1) enhanced chilling tolerance in apricot flower maybe through induction of CBF transcription factor and activations of antioxidative capacity, such as, POD, POD and CAT.

Key words: apricot (Prunus armeniaca) flower; antioxidant enzymes; CBF; chilling; salicylic acid