Engineering Root Architecture with New Tools for Controlling Gene Expression in Plants

The shape of a plant’s root system influences its ability to reach essential nutrients in the soil or to acquire water during drought. Progress in engineering plant roots to optimize water and nutrient acquisition has been limited by our capacity to design and build genetic programs that alter root growth in a predictable manner. We are building a library of synthetic transcription factors and using them to construct gene circuits that reprogram root development. The genetic circuits will be used to express mutant auxin-response transcription factors (AUX/IAAs) in specific root cell-types to alter root structure. In addition to synthetic gene circuits, we are constructing a platform for site specific integration of transgenes in Arabidopsis. This site specific integration platform should accelerate the development of genetic circuits in plants by reducing the variability in gene expression produced by random transgene integration and shortening the design-build-test cycle. We are currently testing methods of preventing random T-DNA integration after Agrobacterium-mediated DNA delivery. If successful and efficient, our platform will direct T-DNAs to integrate a specific location within the plant genome. This will accelerate the pace of plant research by generating clonal plant lines that can be phenotyped in the T1 generation.