Identification of chemical inhibitors for RNase III of Sweet potato chlorotic stunt virus (SPCSV)
Year: 2020
Type: dissertation
Abstract: Viral disease caused by co-infection of Sweet potato feathery mottle virus (SPFMV) and Sweet potato chlorotic stunt virus (SPCSV) is a severe problem that affects the production of sweetpotato (Ipomoea batatas) by reducing crop yields by up to 90%. RNase III encoded by SPCSV (CSR3) has been shown to be a viral suppressor of RNA silencing (VSR) with the ability to counteract the host’s antiviral RNA silencing defense by cleaving small interfering RNA (siRNA). This function of CSR3 is responsible for the synergistic interaction between SPCSV and other viruses including SPFMV. Thus, CSR3 may be an ideal drug target for the development of a new antiviral treatment. Yet, no inhibitor compounds have been developed, and no screening has been carried out. Thus, in this study, we sought to identify chemical inhibitors of CSR3 in order to diminish viral disease in sweetpotato. Inhibitor identification was initiated with virtual screening using computer-aided Glide docking. In total, 6,620 compounds of 136,353 were selected. Then a novel high-throughput screening (HTS) process based on fluorescence resonance energy transfer was carried out, taking into consideration the catalytic activity of CSR3 on siRNA. Of the 6,620 compounds, 109 potential inhibitors were selected according to their percentage of inhibition. Afterward, dose-response assays were performed using our HTS approach, followed by affinity binding assays between compounds and CSR3 using surface plasmon resonance and microscale thermophoresis. In addition, the compounds’ ability to affect viral accumulation in planta was verified using plants grown in a culture medium and in soil with RT-qPCR and imaging-based plant phenotype approach, respectively. As a result, four compounds were confirmed to improve the photosynthesis performance of plants grown in soil and reduce SPFMV accumulation in SPCSV and SPFMV co-infected sweetpotatoes. The study is the first to identify effective inhibitors for CSR3, opens a path toward the development of new strategies to fight viral diseases caused by the synergism of SPCSV.
Source: Työväentutkimus Vuosikirja
Author: Linping Wang
Language: English
Topic: Plant Virus Research Studies
Subfield: Plant Science
Domain: Life Sciences
SDG: Zero hunger
Open Access status: green
OpenAlex ID: W3034852193