As an important tropical crop, Manihot esculenta Crantz is one of the top six global food crops and provides a staple food for nearly 700 million people worldwide. However, diseases caused by virus infection are a serious threat to the development of the cassava industry worldwide. Cassava mosaic disease (CMD) is one of the most threatening diseases, causing serious economic losses. Sri Lankan cassava mosaic virus (SLCMV) is one of the pathogens causing cassava mosaic disease. SLCMV is a typical two-component geminiviruses, and its genome consists of two circular components, DNA-A and DNA-B. Nonsense-mediated mRNA decay (NMD) is one of the major pathways of mRNA degradation in eukaryotic cells and a prevalent antiviral defense mechanism in eukaryotes. More and more studies have shown that NMD is not only an important mechanism for regulating mRNA quantity and quality in eukaryotes, but also degrades viral RNA as well as post transcriptional gene silencing (PTGS), which is a prevalent antiviral defense mechanism in eukaryotes. The mRNA decay process of NMD includes four processes: recognition of PTC, deadenylation, decapitation and final exonuclease degradation, and UPF1, PARN, DCP2 and XRN4 are the key proteins in these four processes, respectively. Viruses are specialized parasitic organisms that must escape or be resistant to degradation by host cells in order to successfully infect. Poly(A)-specific ribonuclease (PARN) is a key factor in the NMD signaling pathway. At present, the molecular mechanism of SLCMV resistance to host NMD is unclear. In this study, we will demonstrate that the silent suppressor AC4 encoded by SLCMV interacts with Arabidopsis PARN using yeast two-hybrid system and bimolecular fluorescence complementation (BiFC) experiments. It is hypothesized that the SLCMV AC4 protein may help the virus evade or tolerate degradation by the host cell by inhibiting the viral defense function of the host NMD through interaction with AtPARN. The results lay the foundation for elucidating the molecular mechanism by which cassava mosaic virus regulates the antiviral defense function of host NMD.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |