glutathione transferase of Nicotiana benthamiana NbGSTU4 plays a role in regulating the early replication of Bamboo mosaic virus

• Published in: The New phytologist Vol. 199; no. 3; pp. 749 - 757
• Main Authors: Chen, I‐Hsuan, Chiu, Meng‐Hsuen, Cheng, Shun‐Fang, Hsu, Yau‐Heiu, Tsai, Ching‐Hsiu
• Format: Journal Article
• Language: English
• Published: England Academic Press 01.08.2013; New Phytologist Trust; Wiley Subscription Services, Inc; Blackwell Publishing Ltd
• Subjects: 3' Untranslated Regions; 3' Untranslated Regions - genetics; Accumulation; Bamboo mosaic virus; Bamboo mosaic virus (BaMV); Bamboos; biosynthesis; Blotting, Western; Cross-Linking Reagents; Cross-Linking Reagents - pharmacology; drug effects; E coli; enzymology; Escherichia coli; Gene Knockdown Techniques; gene silencing; genes; genetics; glutathione; glutathione (GSH); Glutathione - pharmacology; glutathione S‐transferase (GST); glutathione transferase; Glutathione Transferase - metabolism; in vitro RNA replication; Infections; metabolism; Mosaic Viruses; Mosaic Viruses - drug effects; Mosaic Viruses - physiology; Mosaic Viruses - radiation effects; Nicotiana - drug effects; Nicotiana - enzymology; Nicotiana - radiation effects; Nicotiana - virology; Nicotiana benthamiana; Oxidation-Reduction; Oxidation-Reduction - drug effects; Oxidation-Reduction - radiation effects; pharmacology; physiology; Plant Proteins; Plant Proteins - metabolism; Potexvirus; Protoplasts; radiation effects; Real-Time Polymerase Chain Reaction; redox; RNA; RNA, Viral; RNA, Viral - biosynthesis; RNA, Viral - genetics; RNA-Dependent RNA Polymerase; RNA-Dependent RNA Polymerase - metabolism; Tobacco; Ultraviolet Rays; Untranslated regions; Viral RNA; viral RNA replication; Virology; Virus Replication; Virus Replication - drug effects; Virus Replication - radiation effects; Viruses; virus‐induced gene silencing (VIGS); virus-induced gene silencing (VIGS); Bamboo mosaic virus (BaMV); viral RNA replication; glutathione (GSH); glutathione S-transferase (GST); in vitro RNA replication; redox
• ISSN: 0028-646X; 1469-8137; 1469-8137
• DOI: 10.1111/nph.12304

Bamboo mosaic virus (BaMV) is a single‐stranded positive‐sense RNA virus. One of the plant glutathione S‐transferase (GST) genes, NbGSTU4, responds as an upregulated gene in Nicotiana benthamiana post BaMV infection. In order to identify the role of NbGSTU4 in BaMV infection, the expression of NbGSTU4 was knocked down using a virus‐induced gene silencing technique or was transiently expressed in N. benthamiana in BaMV inoculation. The results show a significant decrease in BaMV RNA accumulation when the expression level of NbGSTU4 is reduced; whereas the viral RNA accumulation increases when NbGSTU4 is transiently expressed. Furthermore, this study identified that the involvement of NbGSTU4 in viral RNA accumulation occurs by its participation in the viral early replication step. The findings show that the NbGSTU4 protein expressed from Escherichia coli can interact with the 3′ untranslated region (UTR) of the BaMV RNA in vitro in the presence of glutathione (GSH). The addition of GSH in the in vitro replication assay shows an enhancement of minus‐strand but not plus‐strand RNA synthesis. The results suggest that the plant GST protein plays a role in binding viral RNA and delivering GSH to the replication complex to create a reduced condition for BaMV minus‐strand RNA synthesis.