Jiang Shanshan, Jiang Liangliang, Yang Jian, Peng Jiejun, Lu Yuwen, Zheng Hongying, Lin Lin, Chen Jianping, Yan Fei
College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China; Institute of Plant Protection, Shandong Academy of Agricultural Sciences, Jinan 250100, China.
College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China.
Gene. 2018 Jan 10;639:44-51. doi: 10.1016/j.gene.2017.10.004. Epub 2017 Oct 4.
Plant Xrn4 is a cytoplasmic 5' to 3' exoribonuclease that is reported to play an antiviral role during viral infection as demonstrated by experiments using the Xrn4s of Nicotiana benthamiana and Arabidopsis thaliana. Meanwhile, little is known about the anti-viral activity of Xrn4 from other plants. Here, we cloned the cytoplasmic Xrn4 gene of Oryza sativa (OsXrn4), and demonstrated that its over-expression elevated the 5'-3' exoribonuclease activity in rice plants and conferred resistance to rice stripe virus, a negative-sense RNA virus causing serious losses in East Asia. The accumulation of viral RNAs was also decreased. Moreover, the ectopic expression of OsXrn4 in N. benthamiana also conferred plant resistance to tobacco mosaic virus infection. These results show that the monocotyledonous plant cytoplasmic Xrn4 also has an antiviral role and thus provides a strategy for producing transgenic plants resistant to viral infection.
植物Xrn4是一种细胞质5'至3'外切核糖核酸酶，据报道，在病毒感染期间该酶发挥抗病毒作用，使用本氏烟草和拟南芥的Xrn4进行的实验已证明了这一点。与此同时，对于来自其他植物的Xrn4的抗病毒活性了解甚少。在此，我们克隆了水稻（OsXrn4）的细胞质Xrn4基因，并证明其过表达提高了水稻植株中5'-3'外切核糖核酸酶的活性，并赋予了对水稻条纹病毒（一种在东亚造成严重损失的负链RNA病毒）的抗性。病毒RNA的积累也减少了。此外，OsXrn4在本氏烟草中的异位表达也赋予了植物对烟草花叶病毒感染的抗性。这些结果表明，单子叶植物细胞质Xrn4也具有抗病毒作用，从而为培育抗病毒感染的转基因植物提供了一种策略。
