Synedrella Yellow Vein Clearing Virus
Plants and viruses are constantly involved in a race to outdo one another, and their lives literally depend on this.
- A new study with researchers from National Centre of Biological Sciences (NCBSTIFR), Bengaluru, has discovered a new step in this arms race between the virus called Synedrella Yellow Vein Clearing Virus and the plants it attacks.
- The virus was isolated by the researchers from a plant named Synedrella nodiflora, and it was able to infect tobacco and tomato plant in their studies.
About the virus
- This virus is a representative of the Begomovirus family of viruses. “Begomoviruses are a large family with about 400 members. They infect economically important plants and are a major reason for crop loss.
What is this arms race?
- The virus first attacks the plant, and the plant has defences that are actually counter-attacks – mechanisms that seek to destroy the virus. In turn, the virus develops a counter-counter-attack by trying to escape being destroyed by the plant’s mechanisms. In the case of the Synedrella Yellow Vein Clearing Virus, it happens this way: When the virus attacks the plant, it produces vein-clearing symptoms which make the plant look beautiful.
- The fact, however, is that this does not make it better for the plant. It actually makes it difficult for the plant to produce flowers and fruits.
- Without BetaC1, a viral protein, the virus will not be able to defeat the host attacks and also will not be able to completely infect the plant, as the virus will not be able to move through the veins of the plant.
- In turn, the plant develops defence mechanisms to destroy the virus. It targets the protein called BetaC1 made by the virus which helps in successful infection and intracellular movement within the plant. Plants degrade BetaC1 protein of virus by tagging this protein with another smaller protein called ubiquitin.
How does the virus respond to it?
- The virus uses the plant’s machinery to create a small modification of the BetaC1 protein. It adds a tiny protein called SUMO to the betaC1 protein in a process termed SUMOylation.
- BetaC1 hijacks the SUMO pathway machinery of the plants and makes itself a substrate for SUMOylation.
- Essentially, BetaC1 mimics or tricks the host SUMOylation machinery as if it is one of the host plant protein requiring SUMOylation.