Abstract
Plant virus causes massive crop losses globally.However,there is currently no effective measure to control plant viral disease.Previously,we identify an antiviral protein Rhp-PSP,produced by the bacterial Rhodopseudomonas palustris strain JSC-3b.In this study,we discover that the antiviral activity of Rhp-PSP relies on its endoribonuclease activity.Converting the arginine(R)residue at position 129 onto alanine(A)abolishs its endoribonuclease activity on coat protein(CP)RNA of tobacco mosaic virus(TMV),consequentially,compromises the antiviral activity of Rhp-PSP.Further investigation demonstrates that,the mutant Rhp-PSPR129A is unable to form the homotrimer as the wild type,indicating the importance of quaternary junction for the endoribonuclease activity.Overexpression of Rhp-PSP in Nicotiana benthamiana significantly enhances the resistance against TMV of seedlings,while expression of Rhp-PSPR129Adid not,confirming that endoribonuclease activity is responsible for the antiviral activity of Rhp-PSP.In addition,foliar spray of Rhp-PSP solution on tomato and pepper plants significantly reduces the disease index of viral diseases,indicating that Rhp-PSP shows potential to develop antiviral agent in practice.
基金项目
国家重点研发计划(2022YFD1400700)
湖南省重点研发计划(2022NK2014)
Hunan Natural Science Foundation,China(2022JJ40234)
Agricultural Science and Technology Innovation Fund Project of Hunan Province,China(2022CX1)
Changsha Natural Science Foundation,China(kq2202338)