Microbes help plant fitness

By: Eileen Martinez

Changes in the environment, such as drought, flooding, introduction of animals, etc, often lead to evolutionary responses in organisms, and in this study, researches examine how the microbial community in soils play a role in plant changes over time in a stressed environment.  By studying the plant's response to soil moisture in both wet and dry soils, the scientists were able to measure flowering, growth, height, and fruits of the plant; nitrogen levels, ammonia levels, and carbon levels in the soil; and DNA changes in the microbes to determine the responses to the environment.  The scientists found that the microbes had rapid responses to their changing environments, and that these responses dictated/induced responses of the plants. Furthermore, the plants responded positively to the soil microbial community when the microbes had already adapted to the changes in the environment. Finally, the scientists concluded that plant adaptations to their environment is highly influenced by the microbial community in the soil and its interaction with the microbes.  This is important because it helps scientists understand the mechanisms behind organisms adapting and evolving to their environment as well as how future environmental changes will affect organisms, which in the long run can help us preserve these organisms.

Figure from Lau & Lennon (2012) depicts microbial communities effect on plant's number of flowers, number of fruits, and date of flowering in both dry and wet soil conditions over a period of time.   

Original article: Lau JA, Lennon JT. (2012). Rapid responses of soil microorganisms improve plant fitness in novel environments. PNAS Journal 109:14058-14062.