Question: What is the most interesting bacteria you have found inside any of the plants you have used for research? if so, how is it interesting (is it medicinal bacteria like penicillin, toxic like poison, etc.)

Glyn Barrett answered on 20 Mar 2013:

There are two really interesting bacteria which are on a par with each other.
They both have really long and weird names so do bear with me 🙂

The first is Pseudomonas syringae which is a very serious plant pathogen and kills millions and millions of plants around the world every year. Its name comes from the fact that it produces lots of little sharp hollow tubes just like syringes which penetrate the plant tissue. The bacteria then injects the plants with toxic proteins which spread through the plant causing disease and most often death. Ive worked on isolating these toxic proteins so I can study them and find out exactly what they do. Its all really cool and exciting but the bad thing is everything is done in big machines and computers so you never really see with your own eyes what you are doing.

The second one is Agrobacterium tumefaciens (I know very silly name!). Ive worked with it on occasion. Its a bacterium which can pass its DNA into plants and cause tumours or cancerous cells. In the wild is causes really serious deformations in plants. look at this image, its pretty horrible

However this ability to pass DNA it very useful for molecular biologists who work in biotechnology as it can be used to improve things like plant growth and protection against infection.