PS Seminar Series - Reprogramming plants: Building gene circuits to alter plant function

Abstract:Plant biotechnology predominantly relies on a restricted set of genetic parts with limited capability to customize spatiotemporal and conditional expression patterns. Synthetic gene circuits have the potential to integrate multiple customizable input signals through a processing unit constructed from biological parts to produce a predictable and programmable output. Here I present a set of functional recombinase-based gene circuits for use in plants. We developed a range of operational logic gates using the identify function (activation) and negation function (repression) in Arabidopsis protoplasts and in vivo, demonstrating their utility for programmable manipulation of transcriptional activity in a complex multicellular organism. Specifically, using recombinases and plant control elements, we activated transgenes in YES, OR and AND gates and repressed them in NOT, NOR and NAND gates; we also implemented the A NIMPLY B gate that combines activation and repression. This highly compact programmable gene circuit platform provides new capabilities for engineering sophisticated transcriptional programs and previously unrealized traits into plants.

Biography: Dr James P B Lloyd (He/Him/They/Them), University of Western Australia’s School of Molecular Sciences and ARC Centre of Excellence in Plant Energy Biology. A geneticist interested in synthetic biology, RNA biology and epigenetics. Since 2018, I have been a Research Associate at the University of Western Australia, working with Prof Ryan Lister creating gene circuits for plants. Starting in 2005, I studied Genetics (with a year in industry) at the University of York (UK) where I worked in the group of Prof Dame Ottoline Leyser FRS DBE for my final year research project exploring the genetic basis of shoot architecture. My year in Industry was at Advanced Technologies Cambridge working on plant genetic engineering. In 2009 I won a Sainsbury Studentship in Plant Sciences to fund my PhD with Prof Brendan Davies at the University of Leeds (UK) working on nonsense-mediated mRNA decay (NMD) in plants. In 2014 I became a post-doc at the University of California, Berkeley (USA), initially working with Prof Daniel Zilberman and Prof Steven Brenner on splicing before continuing at Berkeley as part of the Center for RNA Systems Biology working on splicing and NMD.