Bacteria "Sniffs Out" Plant Wounds

Crown gall is a disease of many woody species caused by a common soil bacterium, Agrobacterium tumefaciens. The disease causes considerable losses for fruit and wine grape growers. New research shows how the pathogen infects its hosts, using a protein sensor to "sniff out" compounds emitted from plant wounds. The findings will help scientist develop controls for the gall tumours.

A ring of DNA, called a plasmid, is used by the bacterium to infect a host and form a gall tumour. The plasmid is separate from the chromosome of the bacterium and not essential for its function. A protein on the plasmid detects phenols leaking from the wound, triggering a sharp increase in the plasmid's rate of replication, providing the strength needed to invade the plant's DNA and form tumours.

The findings could also aid biotechnology reseachers. Agrobacterium tumefaciens has been widely used to introduce new DNA into plant cells to create transgenic plants.

Links:

• Costly plant tumors are found by Cornell microbiologist to be result of soil bacterium 'smelling' and entering wound A Cornell University news release



• Biology and Control of Crown Gall (Agrobacterium tumefaciens) from the University of Edinburgh

Posted by Eric La Fountaine at 10:49 AM on November 15, 2005