Exploring the phytoplasmas, plant pathogenic bacteria

Abstract

Phytoplasmas are plant pathogenic bacteria associated with devastating damage to over 700 plant species worldwide. It is agriculturally important to identify factors involved in their pathogenicity and to discover effective measures to control phytoplasma diseases. Despite their economic importance, phytoplasmas remain the most poorly characterized plant pathogens, primarily because efforts at in vitro culture, gene delivery, and mutagenesis have been unsuccessful. However, recent molecular studies have revealed unique biological features of phytoplasmas. This review summarizes the history and recent progress in phytoplasma research, focusing on (1) the discovery of phytoplasmas, (2) molecular classification of phytoplasmas, (3) diagnosis of phytoplasma diseases, (4) reductive evolution of the genomes, (5) characteristic features of the plasmids, (6) molecular mechanisms of insect transmissibility, and (7) virulence factors involved in their unique symptoms. © 2014 The Author(s).