乙烯在赭曲霉毒素A(OTA)诱导的拟南芥毒性中的作用  

Role of Ethylene in Ochratoxin A (OTA) Toxicity to Arabidopsis thaliana

作　　者：郝俊冉[1] 彭晓丽[1] 许文涛[1,2,3] 吕杨俊 翟亚楠[1] 黄昆仑[1,2,3] 

机构地区：[1]中国农业大学食品科学与营养工程学院,北京100083 [2]农业部转基因生物食用安全检验监督测试中心,北京100083 [3]营养健康与食品安全北京市重点实验室,北京100083

出　　处：《农业生物技术学报》2013年第12期1413-1419,共7页Journal of Agricultural Biotechnology

基　　金：北京市科技计划项目(No.D121100003112001;No.D121100003112004)

摘　　要：赭曲霉毒素A(ochratoxin A,OTA)是毒性最强的真菌毒素之一,具有较强的动物毒性和植物毒性。乙烯(ethylene,ETH)作为植物激素能够调节植物生长、发育、响应生物及非生物胁迫的多个环节,但是乙烯在OTA诱导的拟南芥(Arabidopsis thaliana)植物毒性中的作用尚不清楚。本研究利用气相色谱测定了OTA处理下拟南芥叶片乙烯和乙烯前体氨基环丙烷羧酸(1-aminocyclopropane-1-carboxylic acid,ACC)含量的变化。结果显示,OTA胁迫促进了ETH和ACC含量的上升;通过实时荧光定量PCR检测到OTA能诱导ETH合成限速酶——ACC合成酶(ACC synthase,ACS)基因ACS6的表达,且这种诱导作用与OTA的胁迫时间有关;ACC和乙烯作用抑制剂(AgNO3)分别与OTA作用处理拟南芥叶片后,观察到ACC能加重OTA引起的叶片坏死斑,增加相对电导率和活性氧含量,加剧OTA对叶片的伤害,而AgNO3则引起相反的作用效果,缓解OTA引起的植物损伤。本研究结果表明,乙烯参与了OTA诱导拟南芥毒性的过程,并且乙烯在拟南芥响应OTA胁迫中可能起到负调控的作用。本研究初步明确了乙烯在OTA诱导的拟南芥毒性中的作用与部分机理,为深入研究OTA植物毒性致毒机理提供了基础资料。Ochratoxin A （OTA） is one of the most toxic mycotoxins to both animals and plants. Ethylene （ETH）, as a gaseous plant hormone, contributes greatly to a wide range of cellular and developmental processes, and it responses to abiotic and biotic stress. However, the role of ETH in OTA toxicity to Arabidopsis thaliana is not uncovered. In this study, ETH and the ethylene biosynthetic precursor 1-aminocyclopropane-1-carboxylic acid （ACC） content of A. thaliana leaves exposed to OTA were measured by high performance liquid chromatography. The results showed that OTA treatment increased ETH and ACC content in A.thaliana leaves. Quantitative Real-time PCR was performed to determine the relative expression level of ACC synthase gene 6 （ACS6） which is an important gene in ETH synthesis, and ACS6 expression was induced by OTA and the effect was related to the treatment time of OTA. When exogenous ACC with OTA was added to A.thaliana leaves, aggravated lesions, promoted relative leakage rate and increased reactive oxygen species content were observed, showing that ACC could intensify the damage of OTA to leaves. What was in contrast with the results above was that in the presence of the ethylene receptor antagonist Ag＋ by addition of AgNO3, the toxicity of OTA to A.thaliana leaves was lessened. The research indicated the involvement of ETH in phytotoxicity of OTA as a possible negatively regulator. This study preliminary reveals the role and partly mechanism of ETH in phytotoxicity of OTA to A.thaliana, and can provide foundation for further research on the mechanism of phytotoxicity of OTA.

关 键 词：拟南芥 赭曲霉毒素A(OTA) 乙烯 毒性 

分 类 号：S859.87[农业科学—临床兽医学]