JERUSALEM, Jan. 5 (Xinhua) -- Israeli researchers have discovered a unique mechanism in marine bacteria that protects them from virus attacks, the Israel Institute of Technology (Technion) said in a statement on Sunday.

A new study published in Nature Microbiology focused on the battle between bacteria and phages, viruses that infect bacteria. This constant struggle leads to the mutual evolution of these two populations in marine environments.

In some areas, viral infections drastically reduce large bacterial populations, and without resistance mechanisms, the bacteria would be wiped out.

The study revealed that bacteria use a passive defense mechanism against viruses, involving extremely low doses of molecules in protein creation during genetic translation.

The research examined the relationship between Synechococcus, a marine bacterium, and the phage Syn9.

Synechococcus is crucial because it produces oxygen through photosynthesis and is a key contributor to the food chain, making it vital to marine ecosystems.

The researchers found that Synechococcus resists Syn9 by lowering the levels of transfer RNA (tRNA), a molecule essential for gene translation.

When tRNA levels are normal, the bacteria are more susceptible to the virus, but when tRNA levels are reduced, resistance increases.

This pattern of resistance is passive, with the loss of certain intracellular functions boosting the bacteria's ability to survive viral infection.

The researchers noted that this resistance does not stop the phage from entering the bacterial cell but prevents new virus formation, allowing the bacteria to survive.

They assessed that this resistance evolved gradually through evolution due to selective pressure, meaning that bacteria with reduced tRNA levels survived longer and established bacteria lineages protected from viral infection.

They concluded that this passive resistance is widespread and not limited to the Synechococcus-Syn9 relationship. ■