( Cooperative State Research Education a...)Genome study of beneficial microbe may help boost plant health

The article in Nature Biotechnology presents the first complete genome sequence of a biological control agent for combating plant diseases.

P. fluorescens Pf-5 was discovered two decades ago by Charles R. Howell, a plant pathologist with the ARS in Texas, who showed that the microbe suppressed two major cotton diseases. Since then, plant pathologists around the world have used this strain as a laboratory model to study beneficial microbes.

Paulsen says the P. fluorescens project also pioneered a new methodology. This novel approach relies on the analysis of repeated regions of the DNA sequence to help identify segments of the genome that appear to have been transferred from other microbes or viruses, known as phages, that infect bacteria.

Says Paulsen: "We found exciting evidence that P. fluorescens may have acquired new clusters of genes, called genomic islands, by means of lateral transfer from phages or other microbes."