Characterization of function of polycistronic snoRNA transcripts with active translation in Arabidopsis thaliana

An extensive reannotation of Brassicaceae long non-coding RNAs (lncRNAs) was performed by Palos et al. (2022), yielding over 20k putative previously uncharacterized Arabidopsis lncRNAs, with some containing short open reading frames (sORFs) with evidence of translation. A smaller subset of these translated lncRNAs give rise to small nucleolar RNAs (snoRNAs) and are referred to as polycistronic snoRNA transcripts with active translation (PSTATs) in the Nelson lab. Of these actively translated lncRNAs, a polycistronic transcript disrupted by a TDNA insertion line was identified as PSTAT1. Pstat1 seeds have severe developmental and reproductive defects, and adults are unable to produce pollen and are therefor infertile. RNA modifications mediated by snoRNAs are critical for normal growth, development, and stress responses within Arabidopsis, making the characterization of PSTATS important for bioengineering and crop development. To investigate the impact of altered snoRNA expression, root germination and heat stress assays are being performed on eight PSTAT lines to observe differences in growth, development, and stress when compared to wild type plants. Additionally, we will breed ten new lines by plating seeds and observing potential growth or developmental phenotypes, transferring to soil, genotyping for homozygous mutants, collecting the seeds, and performing the previously mentioned experiments. Characterization of PSTATs will contribute to our growing understanding of the Arabidopsis genome, laying the groundwork for future genomic studies.