A team from the Technion Faculty of Biology has discovered how marine viruses use a “Trojan horse” strategy to exploit the energy systems of ocean bacteria, reshaping key global processes. The study, published in Nature, reveals that cyanophages—viruses that infect oceanic cyanobacteria—carry a hijacked bacterial gene, nblA, which dismantles the bacteria’s photosynthetic machinery.

Under normal stress, this gene helps cyanobacteria survive by recycling components of their photosynthetic systems. However, when activated by the virus, it turns against the host: the virus triggers the breakdown to release amino acids it then uses to replicate rapidly. This allows the virus to exploit the host’s resources while destroying it from within.

The discovery was made by Prof. Debbie Lindell, Prof. Oded Béjà, and Prof. Oded Kleifeld, together with Dr. Omer Nadel, Dr. Rawad Hanna, and Dr. Andrey Rozenberg, using a combination of genetic engineering, proteomics, and environmental metagenomics to map the process in detail.

The researchers estimate that this viral mechanism reduces the global photosynthetic energy production of marine cyanobacteria by about 5%, with potential implications for the Earth’s carbon and oxygen cycles.