A New Israeli Tobamovirus Isolate Infects Tomato Plants Harboring Tm-22 Resistance Genes

PLoS One. 2017 Jan 20;12(1):e0170429. doi: 10.1371/journal.pone.0170429. eCollection 2017.

Abstract

An outbreak of a new disease infecting tomatoes occurred in October-November 2014 at the Ohad village in Southern Israel. Symptomatic plants showed a mosaic pattern on leaves accompanied occasionally by narrowing of leaves and yellow spotted fruit. The disease spread mechanically and rapidly reminiscent of tobamovirus infection. Epidemiological studies showed the spread of the disease in various growing areas, in the South and towards the Southeast and Northern parts of the country within a year. Transmission electron microscope (TEM) analysis showed a single rod-like form characteristic to the Tobamovirus genus. We confirmed Koch's postulates for the disease followed by partial host range determination and revealed that tomato cultivars certified to harbor the Tm-22 resistance gene are susceptible to the new viral disease. We further characterized the viral source of the disease using a range of antisera for serological detection and analyzed various virus genera and families for cross-reactivity with the virus. In addition, next generation sequencing of total small RNA was performed on two cultivars grown in two different locations. In samples collected from commercial cultivars across Israel, we found a single virus that caused the disease. The complete genome sequence of the new Israeli tobamovirus showed high sequence identity to the Jordanian isolate of tomato brown rugose fruit virus.

MeSH terms

  • Enzyme-Linked Immunosorbent Assay
  • Genes, Plant*
  • High-Throughput Nucleotide Sequencing
  • Immune Sera
  • Israel
  • Phylogeny
  • Plant Leaves / virology
  • Reverse Transcriptase Polymerase Chain Reaction
  • Solanum lycopersicum / classification
  • Solanum lycopersicum / genetics
  • Solanum lycopersicum / virology*
  • Tobamovirus / pathogenicity*

Substances

  • Immune Sera

Grants and funding

This work was supported by the Chief Scientist, Israel Ministry of Agriculture, Management of Tm-22 Tobamo breaker in tomato plants, initiative project number 261-1159.