Ruben Rellan Alvarez, Dinneny Lab - Carnegie Institution - Plant Department, Multilayer mapping of root adaptive responses to soil environmental cues.
Plant roots explore and monitor the heterogeneous soil profile to provide nutrients and water to the aerial part of the plant, establish associations with other organisms and provide mechanical support. Plants have different types of roots that individually sense signals from their local environment, integrate them with whole plant signals and continuously adjust their growth rates, angles and metabolic activity defining an intricate network known as root system architecture.
Current methods for analyzing root system architecture at high resolution utilize gel-based media that expose roots to light, non-transpiring atmospheric conditions and highly artificial levels and distributions of nutrients. These methods are also very limited in the developmental times that can be studied, usually the first days after seed germination. Due to these limitations the study of processes that involve whole plant sensing of environmental cues such as water or nutrient availability is limited especially at later stages of plant development.
In order to uncover the adaptive mechanisms roots use to support plant growth under different environmental cues, we developed an integrated imaging system called Growth and Luminescence Observatory for Roots (GLO-Roots) that enables root architecture and gene expression patterns to be studied in soil-grown, light-shielded roots. Using GLO-Roots we show that root systems exposed to low-phosphorus or water deficit exhibit changes in branch angle and growth rates that likely provide an adaptive advantage to the plant and enable acclimation to such conditions. Furthermore, we show applications of the GLO-Roots system that allow gene expression patterns to be determined in adult root systems, differentiation of overlapping root systems of different plants as well as tracking co-localization of microbial colonization by commensal bacteria on roots. We propose GLO-Roots as a system that has great utility in presenting environmental stimuli to roots in ways that provoke adaptive responses and also provides tools for characterizing these responses at the molecular level.
followed by a "Goodbye and thank you Ruben and Charlotte" happy hour (sponsored by eLife)