The Impact of Genomic Approaches on Our Understanding of Diversity and Taxonomy of Plant Pathogenic Bacteria
Boris A. Vinatzer and Carolee T. Bull
from: Plant Pathogenic Bacteria: Genomics and Molecular Biology (Edited by: Robert W. Jackson). Caister Academic Press, U.K. (2009)
Our understanding of the diversity of bacterial plant pathogens has changed dramatically over the past 100 years. Initially, it was thought that each newly described disease was caused by a distinct bacterial species. Later, similarities in the physiology and codification of nomenclature resulted in the consolidation of taxa regardless of demonstrated diversity and host range. We have now entered an era in which genomic approaches can reveal genetic diversity in much finer detail. This has resulted in the development of phylogenetic trees, which identify theoretical evolutionary groupings at ranks below the level of the currently described bacterial species. There are cases in which these groupings coincide with previously defined pathovars or genomospecies while in other cases these groups represent biologically or ecologically relevant groups that still need to be defined taxonomically. In this chapter we give an overview of the history of systematics and of bacterial species concepts, describe current genomics approaches to uncover diversity, and finally discuss the potential consequences of the already uncovered genomic diversity on the taxonomy of plant pathogenic bacteria read more ...