摘要
N^(6)-methyladenosine(m^(6)A)is the most abundant eukaryotic mRNA modification and is involved in various biological processes.Increasing evidence has implicated that m^(6)Amodification is an important anti-viral defense mechanism in mammals and plants,but it is largely unknown how m^(6)Aregulates viral infection in plants.Here we report the dynamic changes and functional anatomy of m^(6)Ain Nicotiana benthamiana and Solanum lycopersicum during Pepino mosaic virus(PepMV)infection.m^(6)Amodification in the PepMV RNA genome is conserved in these two species.Overexpression of the m^(6)Awriters,mRNA adenosine methylase A(MTA),and HAKAI inhibit the PepMV RNA accumulation accompanied by increased viral m^(6)Amodifications,whereas deficiency of these writers decreases the viral RNA m^(6)Alevels but enhances virus infection.Further study reveals that the cytoplasmic YTH-domain family protein NbECT2A/2B/2C as m^(6)Areaders are involved in anti-viral immunity.Protein-protein interactions indicate that NbECT2A/2B/2C interact with nonsense-mediated mRNA decay(NMD)-related proteins,including NbUPF3 and NbSMG7,but not with NbUPF1.m^(6)Amodification-mediated restriction to PepMV infection is dependent on NMD-related factors.These findings provide new insights into the functionality of m^(6)Aanti-viral activity and reveal a distinct immune response that NMD factors recognize the m^(6)Areaders-viral m^(6)ARNA complex for viral RNA degradation to limit virus infection in plants.
基金
supported by the National Key Research and Development Program of China (2021YFD1400400) to Fangfang Li
the National Natural Science Foundation of China (32172385 and 31930089) to Fangfang Li and Xueping Zhou, respectively