A sequence change in a single protein made it possible for a tomato virus to become a global crop pandemic

A sequence change in a single protein made it possible for a tomato virus to become a global crop pandemic

Tomato plants (cv. Moneymaker) (upper panel) and leaves (lower panel) homozygous for the tm-2 or Tm-22 allele infected with ToMV and ToMVMP-ToBRFV. Credit: Hagit Hak and Ziv Spiegelman

In recent years, a new viral tomato disease has emerged that threatens tomato production worldwide. This is caused by the Tomato brown rugose fruit virus (ToBRFV), a member of a destructive group of plant viruses called tobamovirus. ToBRFV overcomes all known tobamovirus resistance in tomatoes, including that conferred by Tm-22, a resistance gene that is responsible for the stable resistance to these viruses for more than 60 years. In a study recently published in Molecular plant-microbe interactions (MPMI), journal, Dr. Ziv Spiegelman and Dr. Hagit Hak explored the molecular mechanism by which this new virus was able to break this resistance and become a devastating global crop pandemic.

“Tm-22 encodes a plant immune receptor protein that recognizes a virally encoded protein called locomotor protein that triggers an immune response against a wide variety of tobamoviruses. ToBRFV is the first virus that was able to overcome the durable Tm-22 resistance gene, “said Spiegelman.” We found that the ToBRFV locomotor protein contained sequence changes that allowed it to avoid Tm-22. We confirmed this by introducing this new sequence to another virus (the tomato mosaic virus), which normally cannot infect plants harboring Tm-22, which resulted in a virulent virus. “

Moreover, they came up with an interesting observation from an evolutionary point of view. Viral locomotor proteins allow the virus to spread from cell to cell and infect the entire plant. We found that the elements that enabled the locomotor protein to avoid Tm-22 recognition probably resulted in reduced viral movement. This suggests that the virus pays a penalty to avoid host resistance, which is a reduced cell-to-cell transport. This finding may explain the high durability of Tm-22 resistance that had been unbroken for more than half a century, “Spiegelman said.


How cells defend themselves against influenza A virus


More information:
Hagit Hak et al., The Tomato Brown Rugose Fruit Virus Movement Protein Overcomes Tm-22 Resistance in Tomato While Suppressing Viral Transport, Molecular plant-microbe interactions (2021). DOI: 10.1094 / MPMI-01-21-0023-R

Provided by the American Phytopathological Society

Citation: A sequence change in a single protein made it possible for a tomato virus to become a global crop pandemic (2021, November 2) retrieved November 2, 2021 from https://phys.org/news/2021-11-sequence-protein-tomato -virus -global.html

This document is subject to copyright. Apart from any reasonable trade for the purpose of private investigation or research, no part may be reproduced without written permission. The content is provided for informational purposes only.

Leave a Comment