Microbial Control of Root-Pathogenic Fungi and Oomycetes

Authors: Thomashow, Linda; BAKKER, PETER A.H.M. - Utrecht University

Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 4/15/2014
Publication Date: N/A
Citation: N/A

Interpretive Summary: The rhizosphere includes the root surface and the surrounding soil that is influenced by nutrients provided by the root. Microbes introduced into the rhizosphere must be able to compete successfully for these nutrients in order to either reduce the impact of disease-causing pathogens directly or by inducing the plant’s own defense mechanisms. Much has been learned in recent years about the biological activities of beneficial root-associated bacteria that have been introduced to reduce the impact of plant pathogens, but the physical, chemical and biological activities that take place between microbes and the root surface are still poorly understood because techniques for studying interactions in this region tend to disrupt the microbe-root association. This chapter provides an overview and introduction to recent progress toward understanding the factors that limit successful introduction of bacteria to control root pathogens and the mechanisms involved in pathogen control. More detailed chapters elsewhere in this volume address related topics including the ability of some introduced bacteria to stimulate plant growth, reduce environmental stress, and enable the plant’s own defense mechanisms to respond more rapidly and strongly to pathogen attack. Other chapters describe powerful new biotechnological and nondisruptive advances that are able to provide novel insight into root-microbe interactions.

Technical Abstract: The rhizosphere is a complex and dynamic environment in which microbes introduced to control root pathogens must establish and maintain populations of sufficient size and activity to antagonize pathogens directly or by manipulating the host plant’s own defenses. Genetic and physiological studies of rhizobacteria with the capacity to control root pathogens have given considerable insight into the microbial side of these interactions, but much remains to be learned about the physical conditions and the chemical and biological activities that take place at the root-microbe interface. This chapter focuses on advances in our understanding of the constraints to the successful introduction of microbial agents for the control of soil-borne root pathogens and the mechanisms involved in pathogen suppression. Chapters elsewhere in this volume address related topics including plant growth promotion, stress control, the priming of the plant’s own defense mechanisms by introduced microbes, and powerful new biotechnological advances available to gain insight into rhizosphere processes.