How plants become zombies
Date: 11.4.2014
Some plants are zombies and scientists have uncovered how bacterial parasites turn them into the living dead.
"For the first time, we can reveal how this remarkable manipulation takes place," says Professor Saskia Hogenhout from the John Innes Centre. "In that sense, the plant world is ahead of animal biology – where manipulations also take place but no mechanisms have been uncovered to show how."
The plant parasite in her study is dependent on both insects to spread and plants on which to grow. It induces the plant to transform its flowers into leaf tissue, sacrificing its reproductive success and becoming sterile. It is now a zombie plant – dead to the future and destined to benefit only the survival of the bacteria.
Scientists in the labs of Professor Hogenhout at JIC, and Professors Angenent and Immink at Wageningen University in the Netherlands, have discovered that the parasitic bacterium produces a protein called SAP54 that is essential to this process. The protein is dependent for its activity on a family of plant proteins called RAD23.
When leafhoppers eat infected plant material, the bacteria colonize the insects, including their salivary glands. If the insect dribbles saliva as it sucks on another plant, the bacteria are able to spread into new plant tissue. The bacteria set to work on making the plant more attractive to leafhoppers.
