Multi-phased internalization of murine norovirus (MNV) in <i>Arabidopsis</i> seedlings and its potential correlation with plant defensive responses

다국어 초록 (Multilingual Abstract)

<P><B>Abstract</B></P> <P>Norovirus is a highly infectious human pathogen that causes acute foodborne diseases worldwide. As global diet patterns have begun to incorporate a higher consumption of fresh agricultural products, the internalization of norovirus into plants has emerged as a potential threat to human health. Here, we demonstrated that murine norovirus (MNV1) was internalized into <I>Arabidopsis</I> in multiple phases, and this internalization was correlated with <I>Arabidopsis</I> innate immunity responses. Under hydroponic conditions, continuous treatment of MNV1 retarded root growth and facilitated flower development of <I>Arabidopsis</I> without causing necrotic lesions. Examination of viral titers and RNA levels revealed that MNV1 was internalized into <I>Arabidopsis</I> in at least three different phases. In response to MNV1 treatment, the <I>Arabidopsis</I> defensive marker <I>PR1</I> (a salicylic acid signaling marker) was transiently up-regulated at the early stage. <I>PDF1.2</I>, a jasmonic acid signaling marker, exhibited a gradual induction over time. Noticeably, <I>Arabidopsis RNS1</I> (T2 ribonuclease) was rapidly induced by MNV1 and exhibited anti-correlation with the internalization of MNV1. Exposure to recombinant <I>Arabidopsis</I> RNS1 protein reduced the viral titers and degraded MNV1 RNA <I>in vitro</I>. In conclusion, the internalization of MNV1 into <I>Arabidopsis</I> was fluctuated by mutual interactions that were potentially regulated by <I>Arabidopsis</I> immune systems containing <I>RNS1</I>.</P> <P><B>Highlights</B></P> <P> <UL> <LI> MNV1 treatment altered the root growth and floral transition of <I>Arabidopsis</I>. </LI> <LI> The internalization of MNV1 into <I>Arabidopsis</I> occurred in multiple phases. </LI> <LI> Plant immune responses potentially modulated the MNV1 internalization. </LI> <LI> <I>Arabidopsis</I> ribonuclease <I>RNS1</I> negatively regulated MNV1. </LI> </UL> </P>