珙桐叶肉细胞中的核内含体

The ultrastructure of intranuclear inclusions in leaf mesophyll cells of Davidia involucrata was investigated with electron microscopy.Intranuclear inclusions occur generally in the cells of young and mature leaves.They consist of numerous bundles aggregated by several fibres (diameter about 10 nm),sometimes a few of bundles turn to tubules enveloped by fibres.Authors suggested that it is a new subtype (F2) of intranuclear fibrillar inclusion.

PRSV-NIb基因同源dsRNA的原核表达及其在番木瓜叶片原生质体瞬时表达体系中诱导RNA沉默的研究

为探索利用PRSV-NIb基因同源dsRNA的原核表达产物在体外防治番木瓜环斑病毒的可行性,利用较保守的PRSV-NIb基因3′端的312、501和809 bp区段分别构建了含有PDK内含子的3个发夹RNA编码结构,并选用pSP73和M-Jm109LacY分别作为宿主载体和宿主菌构建了高效的dsRNA原核表达工程菌M-Jm109LacY/pSP73-RNAi-N312、M-Jm109LacY/pSP73-RNAi-N501、M-Jm109LacY/pSP73-RNAi-N809,经IPTG诱导成功表达了dsRNA,并证明dsRNA不被DNase I和RNase A降解,稳定性较好。还利用PRSV-NIb基因构建了GFP瞬时植物融合表达载体pNIb-GFP,对经3种dsRNA和GFP瞬时融合表达载体共转化的番木瓜叶片原生质体的共聚焦显微镜观察及通过半定量RT-PCR对其中mRNA表达量的分析,结果表明融合基因NIb-GFP的表达均发生了不同程度的下调,说明dsRNA在原生质体中引发了针对同源基因的沉默。