A fijiviral nonstructural protein triggers cell death in plant and bacterial cells via its transmembrane domain. (28th October 2022)

• Record Type: Journal Article
• Authors: Yuan, Zhengjie; Geng, Yanfei; Dai, Yuanxing; Li, Jing; Lv, Mingfang; Liao, Qiansheng; Xie, Li; Zhang, Heng‐Mu
• Is Part Of: Molecular plant pathology. Volume 24:Number 1(2023)
• Page Start: 59
• Page End: 70
• Publication Date: 2022-10-28
• Subjects: cell death -- fijivirus -- transmembrane domain -- viral nonstructural protein; Plant diseases -- Molecular aspects -- Periodicals; Plant-pathogen relationships -- Molecular aspects -- Periodicals; 571.936
• DOI: 10.1111/mpp.13277
• Languages: English
• ISSNs: 1464-6722

Abstract

Abstract: Southern rice black‐streaked dwarf virus (SRBSDV; Fijivirus, Reoviridae ) has become a threat to cereal production in East Asia in recent years. Our previous cytopathologic studies have suggested that SRBSDV induces a process resembling programmed cell death in infected tissues that results in distinctive growth abnormalities. The viral product responsible for the cell death, however, remains unknown. Here P9‐2 protein, but not its RNA, was shown to induce cell death in Escherichia coli and plant cells when expressed either locally with a transient expression vector or systemically using a heterologous virus. Both computer prediction and fluorescent assays indicated that the viral nonstructural protein was targeted to the plasma membrane (PM) and further modification of its subcellular localization abolished its ability to induce cell death, indicating that its PM localization was required for the cell death induction. P9‐2 was predicted to harbour two transmembrane helices within its central hydrophobic domain. A series of mutation assays further showed that its central transmembrane hydrophobic domain was crucial for cell death induction and that its conserved F90, Y101, and L103 amino acid residues could play synergistic roles in maintaining its ability to induce cell death. Its homologues in other fijiviruses also induced cell death in plant and bacterial cells, implying that the fijiviral nonstructural protein may trigger cell death by targeting conserved cellular factors or via a highly conserved mechanism. Abstract : Fijiviral P9‐2 protein but not RNA was shown to induce cell death by targeting the plasma membrane in plant cells, suggesting that this protein could be responsible for a programmed cell death‐like process in infected tissues with hyperplasia.