Identification of a tobacco protein interacting with tomato mosaic virus coat protein and facilitating long-distance movement of virus

Abstract

The protein-protein interaction of virus and host is essential for virus infection and host defense. The coat protein (CP) of tomato mosaic virus (ToMV) has been proved to be involved in cell-to-cell and long-distance movements of viruses that are presumably related with the protein-protein interactions. However, the host proteins that interact with the ToMV coat protein (ToCP) are largely unknown. In this study, we isolated a cDNA from a tobacco library through yeast two-hybrid system, which encodes a protein designated the ToMV CP-interacting protein-L (IP-L) that interacted with ToCP in vitro and in vivo. Sequencing analysis revealed that the putative coding region of IP-L gene was identical to that of an 'elicitor responsive protein' gene from N. tabacum (Genbank: #AB040409). A homology was also found between the cDNA sequence of IP-L and two senescence-related cDNAs (SENU1: Z75523 and AY479987) isolated from tomato and pepper. Northern blotting analysis showed that the mRNA level of IP-L was elevated after infection of ToMV. Then, we investigated the in vivo function of IP-L using virus-induced gene silencing (VIGS) and virus challenging assay. Semi-quantitative RT-PCR and Northern blotting results showed that the endogenous mRNA of IP-L in N. benthamiana plant was silenced at 10 days post inoculation with the in vitro transcripts of PVX-IP-L that were produced from the potato virus X (PVX)-based gene silencing plasmid pPC2S.IP-L. The IP-L silent plant developed a delayed systemic symptom at 7 days post challenging with ToMV, indicating that a high expression of IP-L was necessary for the interaction with ToCP to assist the viral transportation. Together, our data suggested that IP-L is a novel plant factor that interacts with the coat protein of ToMV and facilitates the long-distance movement of virus, which may provide a valuable clue for us to further investigate the mechanisms of plant virus infection and to control plant virus diseases.

The Rubisco Small Subunit Is Involved in Tobamovirus Movement and Tm-22-Mediated Extreme Resistance

“…Viral systemic symptom development can be used as an indicator to monitor long-distance trafficking of ToMV and other plant viruses (Leisner et al, 1993;Li et al, 2005;Lewis and Lazarowitz, 2010). In N. benthamiana, ToMV systemic infection resulted in curved apical shoots, crinkled apical leaves, chlorotic mottling of newly emerged leaves, and backward winding of young leaves (Fig.…”

Hibiscus chlorotic ringspot virus upregulates plant sulfite oxidase transcripts and increases sulfate levels in kenaf (Hibiscus cannabinus L.)

“…A putative oxidoreductase, HCP1, interacts with the brome mosaic virus (BMV) CP and affects BMV infection in barley (Okinaka et al, 2003). It has also been reported that high expression of a tomato mosaic virus CP-interacting protein is necessary to assist virus long-distance movement (Li et al, 2005). However, none of these studies has linked CP to its interactions with host proteins in peroxisomes, which play an essential role in specific defence mechanisms conferring resistance against pathogens and also have important functions in metabolism (Koh et al, 2005;Lipka et al, 2005).…”

The Chloroplastic Protein THF1 Interacts with the Coiled-Coil Domain of the Disease Resistance Protein N′ and Regulates Light-Dependent Cell Death

“…Interestingly, part of the TMV CP population localizes inside chloroplasts, where it is thought to induce chlorosis by interfering with PSII functions Beachy, 1986, 1989;Hodgson et al, 1989;Culver, 2002;Lehto et al, 2003). Likewise, a fraction of the ToMV CP has also been reported to localize inside chloroplasts, where it is thought to interact with a thylakoid membrane protein (Li et al, 2005;Zhang et al, 2008).…”