Submitted to: Research Signpost: Research Developments in Agricultural and Food Chemistry
Publication Type: Peer reviewed journal
Publication Acceptance Date: 8/17/2004
Publication Date: 11/16/2004
Citation: Mazzola, M. 2004. Influence of plant genotype on development of interactions with non-symbiotic plant beneficial soil microorganisms. Research Signpost: Research Developments in Agricultural and Food Chemistry. 37:103-122. Interpretive Summary: Soil ecosystems possess a wealth of microbiological resources that can be harnessed for use in control of plant diseases. Many organisms form associations with plants that contribute in a beneficial manner to plant nutrition as well as protection from diseases. However, little emphasis has been placed on understanding the role of the plant in determining the development of these beneficial plant-microbe interactions. Recent studies have demonstrated that these interactions are more specialized than previously believed. This new knowledge may assist in exploiting host genetics through plant breeding programs to enhance development of these naturally occurring benefical plant-microbe interactions. These studies have also demonstrated that development of soil microbial communities that naturally suppress plant diseases can be managed by implementing specific cropping patterns. Again, the importance of not only plant species but also plant genotype (cultivar) was established. Selection fo the appropriate plant cultivar could dramatically reduce the time necessary to induce this disease suppressive state, and may with further adjustment enable use of this disease management practice in an economically feasible manner.
Technical Abstract: The capacity of plant genotype to influence interactions with beneficial plant-associated microorganisms has received minimal examination, and has primarily been limited to the rhizobia-legume interaction and the symbiotic relationship between plants and arbuscular mycorrhizal fungi. Although thought to be unspecialized, recent lines of evidence suggest varying degrees of specialization may exist among plant interactions with saprophytic elements of the soil microbial community. Support for this hypothesis includes the observation that plant cultivars differing in disease susceptibility demonstrate differences in composition of the antagonistic microflora recovered from the rhizosphere; the demonstration of cultivar-specific induction of soil suppressiveness; differential expression of bacterial antibiotic biosynthetic in the rhizosphere of different plant cultivars; and identification of quantitative trait loci in tomato inbred lines which explain a portion of the variation in biocontrol of Pythium torulosum via application of the biocontrol strain Bacillus cereus UW85. These determining genetic composition of certain elements of the resident soil microflora. Identificaiton of genes involved in host selection of plant beneficial microbes could lead to breeding strategies that optimize these interactions, resulting in an effective means to enhance plant growth and control soilborne disease in an ecologically sensitive manner.