Applied Microbiology and Beneficial Microbes

Biography

Biography: Sharon Lafferty Doty

Abstract

Just as the human microbiome is essential for our health, the microorganisms within plants play critical roles in plant growth and health.  The plant microbiota provide numerous benefits to the host plant including nutrient acquisition, phytohormone production, reduced stress responses, antimicrobial production, tolerance to heat, salt, and drought, and pollutant degradation.  We study the microbial endophytes of plants in challenging environments.  Poplar (Populus) and willow (Salix) are pioneer plant species able to colonize the rocky substrates deposited following riparian flooding.  We demonstrated that N-fixation occurs in these non-nodulating plant species, and that N-fixing bacterial species could be cultured from wild poplar and willow and added to hybrid poplar, increasing growth and N-fixation.  Not only did the microbes improve growth of this important bioenergy tree species, they also increased growth, health, and yields of an exceptionally broad range of plant species, including rice, tomato, pepper, strawberries, ryegrasses, and forest tree species under nutrient-limited conditions.  Considering the negative consequences of the production and use of chemical fertilizers, these naturally-occurring bacteria offer a more environmentally-sustainable approach for increasing plant health and growth.  In addition to improving nutrient acquisition, inoculation of plants with endophytes improved water use efficiency and drought tolerance of the host plant.  With the increased stress of climate change, the implications of plant-microbe symbioses for agriculture, forestry, and bioenergy production are profound.

Human health is also impacted by the widespread presence of pollutants, both organic and inorganic.  Phytoremediation, the use of plants to remove environmental pollutants, can be limited by the phytotoxic effects of the chemicals. However, through specific plant-microbe partnerships, these effects can be overcome, leading to substantial improvements in our ability to remove carcinogenic pollutants from the environment.