摘要
将PCR检测呈阳性的T4代转复制酶(replicase,Rep)基因番木瓜植株在苗期接种番木瓜环斑病毒(Papaya ringspot virus,PRSV)Ys株系,定期采取不同部位的叶片进行Northern blot分析。结果表明:接种PRSV之前,在植株的各部位均能检测到转基因完整的Rep mRNA,但接种后不同时间在接种叶以上部位陆续出现了Rep mRNA的降解;接种后30 d内,接种叶下部第1片叶上始终未出现Rep mRNA的降解;另外,在发生mRNA降解的叶片上都能相继检测到小分子干涉RNA(short interferring RNA,si RNA)的产生。这说明转基因番木瓜的抗病性与mRNA的降解及siRNA的积累有着密切的关系。这种抗性发生在转录后水平上,是由病毒诱导的基因沉默(virus-induced gene silencing,VIGS)介导产生的。
T4 plants of transgenic papaya lines were identified by means of PCR,and then were in oculated with Ys strain of Papaya ringspot virus （PRSV） respectively in the greenhouse. Different leaves of the plants were used to extract RNAs periodically, and the RNAs were further analyzed by means of Northern blot. The results showed the levels of the transcript accumulation of the transgene varied in the inoculated transgenic papaya lines and the non-inoculated ones. The non-inoculated transgenic papaya lines could express Rep RNA normally,while the inoculated ones had a low level of accumulation of the RNA transcribed from transgene： the mRNA began to degrade on the 5th day after the inocubation（dpi） on the inocubated leaf,then on the 9th day on the upward leaves. In addition,21-25 nt si RNA could also be detected in the silencing leaves of transgenic papaya lines;however, with in 30 days after inocubation,there were no degradation of Rep mRNA on the downward leave. The results revealed an relation between transgene transcript accumulation and virus resistance. In other words, the resistance of transgenic papaya plants was caused by virus-induced gene silencing.
出处
《华中农业大学学报》
CAS
CSCD
北大核心
2009年第4期418-422,共5页
Journal of Huazhong Agricultural University
基金
国家自然科学基金项目(30370929)资助
关键词
番木瓜环斑病毒
病毒诱导的基因沉默
抗病机制
Papaya ringspot virus （PRSV）
virus-induced gene silencing（VIGS）
resistant mechanism
作者简介
阮小蕾，女，1973年生，博士，讲师．工作单位：华南农业大学资源环境学院，广州510642．E—mail：ruanxl@scau．edu．cn
通讯作者．E-mail：huaping@scau．edu．cn
