Plant-Bacterial Interactions

Abstract

The present emphasis on increased food and fibre production has underscored the need for new methods to control plant diseases and to fertilize crops in ways that are less energy-intensive than those in current practice. Although many approaches to these problems are possible, one area that offers much promise for the future is the study of plant-bacterial interactions. There are several arguments in support of this statement. First, bacteria cause numerous, devastating diseases of plants in the field and of plant products in storage, for which no adequate controls have been devised. Chemical treatments are either too expensive or are ineffective, and breeding for disease resistance is often constrained by the highly variable nature of plant pathogenic bacteria. Thus, alternative means for control must be devised. Second, bacteria take part in associative and symbiotic relationships with plants that are extremely important because they allow better plant growth and endow certain plants with the capacity to fix atmospheric nitrogen. Yet it is clear that the host range of these bacteria and their efficiency under a wide range of environmental conditions are limited, but could be improved substantially if we knew more about the details of their interactions with plants. Thus, this review will attempt to: (a) assess the present status of the field of bacterial plant relationships, with particular emphasis on the nature of the host and parasite/symbiont surface components that come in contact at the initial stages of the interaction, and (b) to point out how this knowledge may lead to new methods for disease control and for increased productivity.