title: Improved Pathogenicity of a Beet Black Scorch Virus Variant by Low Temperature and Co-infection with Its Satellite RNA.
abstract: Co-infection of none-coding satellite RNAs (sat-RNAs) usually inhibits replication and attenuates disease symptoms of helper viruses. However, we find that the sat-RNA ofBeet black scorch virus(BBSV) and low temperature (18°C) additively enhance the systemic infection of BBSV inNicotiana benthamiana. Northern blotting hybridization revealed a relatively reduced accumulation of BBSV-derived small interfering RNAs (siRNAs) in presence of sat-RNA as compared to that of BBSV alone. Cloning and sequencing of total small RNAs showed that more than 50% of the total small RNAs sequenced from BBSV-infected plants were BBSV-siRNAs, whereas the abundance of sat-siRNAs were higher than BBSV-siRNAs in the sat-RNA co-infected plants, indicating that the sat-RNA occupies most of the silencing components and possibly relieves the RNA silencing-mediated defense against BBSV. Interestingly, the 5' termini of siRNAs derived from BBSV and sat-RNA were dominated by Uridines (U) and Adenines (A), respectively. Besides, the infection of BBSV alone and with sat-RNA induce down-regulation of miR168 and miR403, respectively, which leads to high accumulation of their targets,Argonaute 1(AGO1) andAGO2. Our work reveals the profiles of siRNAs of BBSV and sat-RNA and provides an additional clue to investigate the complicated interaction between the helper virus and sat-RNA.
authors.affiliation: State Key Laboratory of Agro-Biotechnology, China Agricultural UniversityBeijing, China; Key Laboratory of Pollinating Insect Biology, Ministry of Agriculture, Institute of Apicultural Research, Chinese Academy of Agricultural SciencesBeijing, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Agro-Biotechnology, China Agricultural University Beijing, China.
authors.forename: Deshui
authors.initials: D
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Agro-Biotechnology, China Agricultural University Beijing, China.
authors.forename: Yongliang
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Agro-Biotechnology, China Agricultural University Beijing, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Agro-Biotechnology, China Agricultural University Beijing, China.
authors.forename: Chenggui
authors.initials: C
authors.lastname: Han
authors.affiliation: State Key Laboratory of Agro-Biotechnology, China Agricultural University Beijing, China.
authors.forename: Dawei
authors.initials: D
authors.lastname: Li
authors.affiliation: State Key Laboratory of Agro-Biotechnology, China Agricultural University Beijing, China.
authors.forename: Jia-Lin
authors.initials: JL
authors.lastname: Yu
authors.affiliation: State Key Laboratory of Agro-Biotechnology, China Agricultural University Beijing, China.
authors.forename: Xian-Bing
authors.initials: XB
authors.lastname: Wang
keywords: RNA silencing; beet black scorch virus; satellite RNA; siRNAs; temperature