Soybean vein necrosis virus (SVNV; genus Tospovirus; Family Bunyaviridae) is a negative-sense single-stranded RNA virus that has been detected across the United States and in Ontario, Canada. In 2013, a seed lot of a commercial soybean variety (Glycine max) with a high percentage of discolored, deformed and undersized seed was obtained. A random sample of this seed was planted in a growth room under standard conditions. Germination was greater than 90% and the resulting seedlings looked normal. Four composite samples of six plants each were tested by reverse transcription polymerase chain reaction (RT-PCR) using published primers complimentary to the S genomic segment of SVNV. Two composite leaflet samples retrieved from seedlings yielded amplicons with a size and sequence predictive of SVNV. Additional testing of twelve arbitrarily selected individual plants resulted in the identification of two SVNV positive plants. Experiments were repeated by growing seedlings from the same seed lot in an isolated room inside a thrips-proof cage to further eliminate any external source of infection. Also, increased care was taken to reduce any possible PCR contamination. Three positive plants out of forty-eight were found using these measures. Published and newly designed primers for the L and M RNAs of SVNV were also used to test the extracted RNA and strengthen the diagnosis of viral infection. In experiments, by three scientists, in two different labs all three genomic RNAs of SVNV were amplified in these plant materials. RNA-seq analysis was also conducted using RNA extracted from a composite seedling sample found to be SVNV-positive and a symptomatic sample collected from the field. This analysis revealed both sense and anti-sense reads from all three gene segments in both samples. We have shown that SVNV can be transmitted in seed to seedlings from an infected seed lot at a rate of 6%. To our knowledge this is the first report of seed-transmission of a Tospovirus.
All four components of brome mosaic virus RNA have m 7 G 5′ ppp 5′ Gp as their 5′ terminus. The m 7 G can be removed by β-elimination, resulting in the conversion to pppGp.
A 47 year old man with multiple myeloma presented with persistent back pain caused by infectious discitis. Aspiration of the affected vertebral disc space was carried out, guided by computed tomography, and microbiological examination of the aspirate revealed Staphylococcus aureus and Mycobacterium tuberculosis. Antituberculous and antistaphylococcal antibiotic treatment resulted in a dramatic clinical response with complete resolution of the vertebral abscess. Detailed radiological and microbiological investigations are necessary to diagnose unusual causes of chronic bone pain such as discitis or infectious bone disease in patients with multiple myeloma.
Brome mosaic virus RNAs 3 and 4 were chemically modified to remove the terminal 7-methyl-guanosine (m7G) structure, and the modified RNAs were tested for their messenger activity in a cell-free system derived from wheat embryo. Amino acid incorporation and ribosome-binding data show that removal of m7G results in reduction, but not complete abolition, of the messenger activity of the RNA. This suggests that the function of m7G may be related to efficient translation of messenger RNA. Possible involvement of other structural factors in RNA translation is discussed.