Curation-based search for the enhancer locus that increases tolerance of a loss of chloroplast translation in Arabidopsis thaliana

Abstract

Arabidopsis thaliana accessions show variation in their response to a loss of chloroplast translation. A duplicated locus (ACC2) encoding homomeric acetyl-coenzyme A carboxylase, an enzyme that functions in fatty acid biosynthesis, was previously identified in the Meinke laboratory as an essential factor in promoting tolerance of a loss of plastid translation. Other unknown loci seem to play a secondary role to ACC2 in enhancing tolerance. One such locus, termed the enhancer due to its proposed role in enhancing ACC2 function, has been mapped to a defined region of A. thaliana chromosome 5 and shows tight linkage to EMB3137 (At5g14320). In this study, we manually curated the region adjacent to EMB3137 and captured detailed information for each locus. We identified enhancer candidates based on their protein function and evaluated how well each candidate fit our models of enhancer function. Our results underscore the range of diverse protein functions encoded by this small region of the A. thaliana genome and point to several loci of potential interest for future studies.