Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Jiangsu Technical Service Center of Diagnosis and Detection for Plant Virus Diseases, no. 50 Zhongling Street, Nanjing, Jiangsu, 210014, China.
Centre SÈVE, Département de Biologie, Université de Sherbrooke, 2500 Blvd. de l' Université, Sherbrooke, QC, J1K 2R1, Canada.
New Phytol. 2019 Oct;224(2):789-803. doi: 10.1111/nph.16049. Epub 2019 Aug 16.
RNA processing and decay pathways have important impacts on RNA viruses, particularly animal-infecting bunyaviruses, which utilize a cap-snatching mechanism to translate their mRNAs. However, their effects on plant-infecting bunyaviruses have not been investigated. The roles of mRNA degradation and non-sense-mediated decay components, including DECAPPING 2 (DCP2), EXORIBONUCLEASE 4 (XRN4), ASYMMETRIC LEAVES2 (AS2) and UP-FRAMESHIFT 1 (UPF1) were investigated in infection of Arabidopsis thaliana by several RNA viruses, including the bunyavirus, tomato spotted wilt virus (TSWV). TSWV infection on mutants with decreased or increased RNA decapping ability resulted in increased and decreased susceptibility, respectively. By contrast, these mutations had the opposite, or no, effect on RNA viruses that use different mRNA capping strategies. Consistent with this, the RNA capping efficiency of TSWV mRNA was higher in a dcp2 mutant. Furthermore, the TSWV N protein partially colocalized with RNA processing body (PB) components and altering decapping activity by heat shock or coinfection with another virus resulted in corresponding changes in TSWV accumulation. The present results indicate that TSWV infection in plants depends on its ability to snatch caps from mRNAs destined for decapping in PBs and that genetic or environmental alteration of RNA processing dynamics can affect infection outcomes.
RNA 加工和降解途径对 RNA 病毒有重要影响，特别是感染动物的 bunyaviruses，它们利用帽抢夺机制来翻译其 mRNAs。然而，它们对感染植物的 bunyaviruses 的影响尚未被研究过。在几种 RNA 病毒（包括 bunyavirus、番茄斑萎病毒（TSWV））感染拟南芥的过程中，研究了 mRNA 降解和无意义介导的衰变成分的作用，包括 DECAPPING 2 (DCP2)、EXORIBONUCLEASE 4 (XRN4)、ASYMMETRIC LEAVES2 (AS2) 和 UP-FRAMESHIFT 1 (UPF1)。在 RNA 去帽能力降低或增加的突变体中，TSWV 感染导致敏感性增加或降低，分别。相比之下，这些突变对使用不同 mRNA 加帽策略的 RNA 病毒没有相反或没有影响。与此一致的是，TSWV mRNA 的 RNA 加帽效率在 dcp2 突变体中更高。此外，TSWV N 蛋白部分与 RNA 加工体（PB）成分共定位，并且通过热休克或与另一种病毒共感染改变去帽活性会导致 TSWV 积累的相应变化。本研究结果表明，TSWV 在植物中的感染取决于其从 PB 中去帽的 mRNAs 抢夺帽子的能力，并且 RNA 加工动力学的遗传或环境改变可以影响感染结果。
