Translational regulation in response to sulfur in Sorghum bicolor

Sorghum is a C4 cereal important not only as food, but also as forage and a bioenergy resource. Its resistance to harsh environments has made it an agriculturally important research subject. Recent accumulation of genomic and transcriptomic information has facilitated genetic studies. Yet genome-wide translational profiles in sorghum are still missing, although increasing evidence has demonstrated that translation is an important regulatory step, and the transcriptome does not necessarily reflect the profile of functional protein production in some organisms. Deep sequencing of ribosome-protected mRNA fragments (ribosome profiling, or Ribo-seq) has enabled genome-wide analysis of translation. In this study, we took advantage of Ribo-seq and identified actively translated reading frames throughout the genome. We detected translation of 7,304 main ORFs annotated in the sorghum reference genome version 3.1 and revealed a number of unannotated translational events. A comparison of the transcriptome and translatome between sorghums grown under normal and sulfur-deficient conditions revealed that gene expression is modulated independently at transcript levels and translation levels. Our study revealed the translational landscape of sorghum's response to sulfur and provides datasets that could serve as a fundamental resource to extend research on sorghum, including translational studies. Overall design: Whole shoot tissues of 13-day-after-sowing Sorghum bicolor grown under Control and sulfur deficiency conditions (Ctrl, 500 µM; Sminus, 0 µM). 3 biological replicates.