《植物生理学报》 2013, 49(4): 357-361

“花壳”病菌对辣椒防御系统的影响

郑文宇, 丁筑红^*, 刘海, 邓程, 肖治柔

贵州大学生命科学学院, 贵州省农畜产品贮藏与加工重点实验室, 贵阳550025

通信作者：丁筑红；E-mail: gzdxdzh@163.com；Tel: 0851-8292117

摘　要：

采用新鲜的红辣椒接种“花壳”病菌, 观察辣椒的色素变化, 并测定活性氧超氧阴离子(O2 ·¯)产生速率, 过氧化氢(H2O2)和羟自由基(·OH)含量, 过氧化物酶(POD)、过氧化氢酶(CAT)和脂氧合酶(LOX)活性变化。结果表明, 与接种普通病菌及对照比较, “花壳”病菌侵染25 d后辣椒的红色完全褪变为黄色或橘黄色; O2 ·¯ 产生速率和·OH含量总体呈先下降后显著上升的变化趋势, 出现单个低峰值; H2O2含量先下降后上升, 到达峰值后又下降; CAT和POD活性变化呈先上升后下降趋势, 出现高峰值, 而LOX活性显著升高, 无峰值出现。接种F101 (Irpex lacteus)和F121 (Cladosporium cladosporioides)病菌对辣椒防御酶系统的影响较接种其他病菌显著。可见, “花壳”病菌对辣椒防御酶系统产生显著影响, 导致大量活性氧爆发, 细胞酶系统抗氧化能力下降, 使其对活性氧的清除能力大大降低, 加剧了活性氧的大量积累和对细胞的损伤。

关键词：辣椒; “花壳”病菌; 活性氧; 防御酶

修定：2013-03-25

资助：国家自然科学基金(31060228/C200301)。

Effect of Pathogens Causing Discoloration on Defensive System in Red Pepper (Capsicum annuum L.)

ZHENG Wen-Yu, DING Zhu-Hong*, LIU Hai, DENG Cheng, XIAO Zhi-Rou

Key Laboratory of Agricultural and Animal Products Store & Processing of Guizhou Province, College of Life Sciences, Guizhou University, Guiyang 550025, China

Corresponding author: DING Zhu-Hong; E-mail: gzdxdzh@163.com; Tel: 0851-8292117

Abstract:

In order to study the effect of pathogens causing discoloration on defensive system in red pepper (Capsicum annuum), we detected the changes in superoxide anion (O2·¯) production rate, hydrogen peroxide (H2O2) and hydroxyl radical (·OH) contents, catalase (CAT), peroxidase (POD) and lipoxygenase (LOX) activi-ties in red pepper infected by pathogens causing discoloration. The results showed that, compared with other pathogens and control group, the pigment in red pepper faded from red to yellow or croci after 25 d infected by the pathogens causing discoloration; the O2·¯ production rate, H2O2 and ·OH contents decreased first and then in-creased. While CAT and POD activities rose then dropped and LOX activity increased slowly. Among the five strains of pathogens, F101 (Irpex lacteus) and F121 (Cladosporium cladosporioides) had stronger influences on defensive enzyme system in red pepper than the others. Therefore, the pathogens causing discoloration could affect the defensive enzyme system in red pepper significantly, which leads to a large accumulation of reactive oxygen species, and a decrease in active oxygen scavenging capacity in the pepper, and even damages to cell.

Key words: red pepper (Capsicum annuum); pathogens causing discoloration; reactive oxygen species; defen-sive enzyme