Chloroplast Proteome of Nicotiana benthamiana Infected by Tomato Blistering Mosaic Virus

Abstract

Tymovirus is a genus of plant pathogenic viruses that infects several dicotyledonous plants worldwide, causing serious diseases in economically important crops. The known cytopathic effect on the host cell organelles involves chloroplast membrane deformation and the induction of vesicles in its periphery. These vesicles are known to be the location where tymoviral genomic RNA replication occurs. Tomato blistering mosaic virus (ToBMV) is a tymovirus recently identified in tomato plants in Brazil, which is able to infect several other plants, including tobacco. In this work, we investigated the chloroplast proteomic profile of ToBMV-infected N. benthamiana using bidimensional electrophoresis (2-DE) and mass spectrometry, aiming to study the virus-host interaction related to the virus replication and infection. A total of approximately 200 spots were resolved, out of which 36 were differentially abundant. Differential spots were identified by mass spectrometry including photosynthesis-related and defense proteins. We identified proteins that may be targets of a direct interaction with viral proteins, such as ATP synthase β subunit, RNA polymerase beta-subunit, 50S ribosomal protein L6 and Trigger factor-like protein. The identification of these candidate proteins gives support for future protein-protein interaction studies to confirm their roles in virus replication and disease development.

The Role of the Chloroplast in the Replication of Positive-Sense Single-Stranded Plant RNA Viruses

“…These data suggest that AltMV replication occurs at the outer chloroplast membrane. Additionally, interaction with the ATP-synthase β subunit was indicated by chloroplast proteome analyses of N. benthamiana plants infected with a member of the Tymovirus genus, tomato blistering mosaic virus (ToBMV), with VRCs adjacent to the chloroplast membrane ( Megias et al, 2018 ). Moreover, in plants infected with ToBMV, increased expression of the chloroplast RNA polymerase β subunit was also observed during ToBMV infection.…”

“…Moreover, in plants infected with ToBMV, increased expression of the chloroplast RNA polymerase β subunit was also observed during ToBMV infection. Considering that viruses encode RNA polymerases, the role of the increased gene expression of chloroplast polymerase during ToBMV infection remains unknown ( Megias et al, 2018 ). Importantly, nuclear-encoded chloroplast RNA polymerases have a direct function in the replication of viroids of the family Avsunviroidae ( Navarro et al, 1999 , 2000 ; Daròs and Flores, 2002 ).…”

Next generation sequencing and proteomics in plant virology: how is Colombia doing?

“…Around the world, proteomics has been widely applied to study plant-virus interactions. It includes crops of economic importance, such as maize and Soybean (Wu et al, 2013;Pavan Kumar et al, 2016), and also plant models, such as tobacco and tomato (Di Carli et al, 2010;Lin et al, 2015;Alexander and Cilia, 2016;Megias et al, 2018). For those readers interested in deepening, Souza et al, (2019) present an excellent review of proteomics applied to several studies of plant-virus interactions.…”

“…In Latin-America, proteomics is less addressed; basically, the country that is leading the research studies on structural, expression and functional proteomics in plant-virus interactions is Brazil. Some examples of researches conducted in Brazil are the study of the chloroplast proteomic profile in Tomato blistering mosaic virus (ToBMV) and Nicotiana benthamiana interaction (Megias et al, 2018), the host proteomic response to Citrus tristeza virus (Dória and Pirovani, 2019) and to the Papaya meleira virus complex (PMeV) (Soares et al, 2017). In Colombia, however, similarly to transcriptomics, proteomics has been little explored.…”

Imaging of Virus-Infected Cells with Soft X-ray Tomography

“…Some other viruses replicate in membrane invaginations, 50-400 nm in diameter, called spherules. These spherules can appear on several enveloped cellular components, depending on the virus that induces them: ER for Flaviviridae and Alphaflexiviridae [14], mitochondria for Nodaviridae [15], chloroplasts for Tymoviruses [16], endosomes and lysosomes for Togaviridae [5] and peroxysomes for Tombusvirus [17]. Finally, other viruses induce the formation of VFs with rather specific morphologies, such as the tubular membrane structures that Bunyaviridae produce around the Golgi [18] or the giant volcano-shaped viral factories of the Mimivirus, which can grow to a size similar to that of the nucleus of the infected host cell [19].…”