A protein-independent fluorescent RNA aptamer reporter system for plant genetic engineering

Reporter systems are routinely used in plant genetic engineering and functional genomics research. Most such plant reporter systems cause accumulation of foreign proteins. Here, we demonstrate a protein-independent reporter system, 3WJ-4 x Bro, based on a fluorescent RNA aptamer. Via transient expression assays in both Escherichia coli and Nicotiana benthamiana, we show that 3WJ-4 x Bro is suitable for transgene identification and as an mRNA reporter for expression pattern analysis. Following stable transformation in Arabidopsis thaliana, 3WJ-4 x Bro co-segregates and co-expresses with target transcripts and is stably inherited through multiple generations. Further, 3WJ-4 x Bro can be used to visualize virus-mediated RNA delivery in plants. This study demonstrates a protein-independent reporter system that can be used for transgene identification and in vivo dynamic analysis of mRNA. Fluorescent RNA aptamers could potentially be used as protein-independent reporters of transgene expression in plants. Here, the authors report that an optimized RNA aptamer, developed from Broccoli, can be used to detect transgene expression in stable and transiently transformed plant tissue.