Upstream open reading frame-mediated upregulation of ANAC082 expression in response to nucleolar stress in Arabidopsis

Perturbations in ribosome biogenesis cause a type of cellular stress called nucleolar or ribosomal stress, which triggers adaptive responses both animal and plant cells. The Arabidopsis ANAC082 transcription factor has been identified as key mediator the response. 5′-untranslated region (5′-UTR) mRNA contains an upstream ORF (uORF) encoding evolutionarily conserved amino acid sequence. Here, we report that this uORF mediates upregulation expression response to stress. When transgenic plants containing luciferase reporter gene under control promoter 5′-UTR were treated with reagents induced was enhanced sequence-dependent manner. Additionally, examined effect endoplasmic reticulum (ER) stress-inducing reagent on because closest homolog Arabidopsis, ANAC103, is involved ER However, did not respond Interestingly, although ANAC103 sequence similar uORF, C-terminal critical for regulation well among homologs Brassicaceae. Transient assays revealed unlike does exert repressive effect. Altogether, our findings suggest important but response, reason, lost during evolution.