A new disease in Tabernaemontana associated with Tobacco mild green mosaic virus

Abstract

Conspicuous viral symptoms were seen on Tabernaemontana divaricata, a member of the family Apocynaceae, grown in a commercial nursery, in Israel. The symptoms varied widely and included chlorotic ringspots and banding, oak-leaf patterns and mosaic. At the end of the winter, large yellow spots, which later became necrotic, appeared on fully expanded leaves. The necrotic zones later fell out, leaving shot holes. Preliminary analysis suggested that the disease was associated with a tobamovirus. Particles typical of a tobamovirus were observed by electron microscopy only in samples taken from symptomatic leaves. A partial segment of the 5 ' -terminus of the viral RNA, which comprised of 533 bp was cloned and sequenced. Comparison of the predicted amino acid sequence with those of other tobamoviruses revealed 94% identity with Tobacco mild green mosaic virus (TMGMV) genome. Primers specific to the coat protein (CP) gene of TMGMV used in a reverse transcription-polymerase chain reaction assay (RT-PCR) gave an expected amplification product of 455 bp. The amino acid composition of the cloned CP gene, which shows a complete identity to that of TMGMV, confirmed the identity of TMGMV infecting Tabernaemontana. Polyclonal antibodies prepared against the virus and used in double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) enabled specific detection of the virus in crude sap extracted from T. divaricata and mechanically inoculated indicator plants. This is the first report of TMGMV infection in Tabernaemontana and the first incidence of the virus in Israel.

Tobacco mild green mosaic virus found naturally infecting Nicotiana glauca in Brazil

“…The near-complete genome has 6.352 nt (GenBank MK005155) and showed 96.74% to 97.67% identities with corresponding nucleotide sequences from different isolates of Tobacco mild green mosaic virus (TMGMV) deposited on GenBank. RT-PCR assays on experimentally inoculated test plants, as well as the original sample of symptomatic N. glauca, using specific pair of primers for coat protein gene of TMGMV (Cohen et al 2001) amplified fragments of expected size (455 bp), confirming the infection by this tobamovirus. TMGMV, originally described by McKinney (1929) in N. glauca in the Canary Island, has been detected infecting N. glauca in several parts of the world, as well as some cultivated plants, and considered of medium risk of potential economic losses (Skelton and Sansford 2012).…”

First report of Tomato brown rugose fruit virus infecting tomato in Florida, USA

“…Tests for common tobamoviruses, i.e. TMV, Tomato mosaic virus, Tomato mottle mosaic virus, (Sui et al, 2017), Tobacco mild green mosaic virus (Cohen et al, 2006), and Tomato brown rugose fruit virus (ToBRFV) (Ling et al, 2019)…”

First report of Pepper mild mottle virus and Tobacco mild green mosaic virus infecting pepper in Panama

“…No differences in symptom expression were observed, except for the infected plant with four viruses, which also showed necrotic symptoms. To confirm these results, total RNA was extracted from these plants and tested by RT‐PCR with primers specific designed to amplify a region of the coat protein gene of CMV (CMV‐D 5′‐CCTCCGCGGATGCTAACTT‐3′ and CMV‐R 5′‐CGGAATCAGACTGGGAGCA‐3′), PMMoV (Takeuchi et al ., 2005), TMGMV (Cohen et al ., 2001), and universal potyvirus degenerate primers (POTY1 5′‐ATGGTKTGGTGYANTGANAA‐3′ and POTY2 5′‐TDHGCWGCNGCYTTCATYT‐3′). Amplicons of the expected size were generated from affected plant tissue, but were not produced from healthy plants or the water used as negative controls.…”