杨金宏;江微;凌君;孔卫青;

• 1:安康学院陕西省蚕桑重点实验室

摘要(Abstract)：

桑花叶萎缩类病毒（Mulberry mosaic dwarf viroid,MMDVd）基因组由单链环状小分子RNA组成，根据预测二级结构可能存在锤头核酶（Hammerhead ribozyme,HH）和疑似发夹核酶（Hairpin ribozyme,HP），但目前还缺乏对核酶活性的研究。本研究使用体外自切割和2,3-环磷酸基测序对核酶活性及自切割位点进行了鉴定，并在发夹核酶Loop1增加一对碱基设计合成了突变核酶MMDVd-HP'，比较了其与MMDVd-HP的活性差异，分析了MMDVd对正常未染病和桑花叶卷叶病相关病毒（Mulberry mosaic leaf roll-associated virus,MMLRaV）阳性桑树的侵染。体外自切割结果显示，所有核酶均成功自切割产生了相应的单体，均有核酶活性。2,3-环磷酸基测序结果显示，腺苷化接头分别连接于第7位的C和302位的A之后，MMDVd-HH的切割位点位于AUC↑处，MMDVd-HP切割位点位于ACA↓处。定量PCR结果显示反应体系中的MMDVd-HP多于MMDVd-HP'，表明MMDVd-HP'更多的发生了切割，活性高于MMDVd-HP。侵染性实验结果显示，桑树（-）没有检测到MMDVd，而所有桑树（MMLRaV）样本均检测到了MMDVd，说明MMDVd能侵染桑树（MMLRaV），与satRNA的特征相似。

关键词(KeyWords)： 桑花叶萎缩类病毒;锤头核酶;发夹核酶;2,3-环磷酸基;切割位点;侵染性

Abstract:

Keywords:

基金项目(Foundation): 陕西省重点研发计划项目(项目号：2018ZDXM-NY-057)，题目：桑树花叶型萎缩病的发生与核酶在植物病害防治中的应用;; 陕西高校青年创新团队项目(项目号：2020AYSC01)，题目：蚕桑科技创新团队~~

作者(Authors): 杨金宏;江微;凌君;孔卫青;

DOI: 10.13242/j.cnki.bingduxuebao.004131

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