Supplementary table, figures and DNA sequences of sorghum gene models SbiRTx430.01G455400 and SbiRTx.02G006600 that feature primers, gRNAs and indels created

In-context promoter bashing via genome editing is a route to identify and
characterize critical regulatory regions that govern expression of genes
of interest. The outcomes of in-context promoter bashing can be used to
inform editing strategies to modulate the expression of selected gene
models in a desired fashion. Here we employed in-context promoter bashing
to characterize the proximal upstream regulatory regions of sorghum genes
encoding phosphoenolpyruvate carboxykinase (Sb.PEPCK.BS,
SbiTx430.01G455400) and alanine aminotransferase (SbiTx430.02G006600,
SbAlaAT.BS), two proteins involved in the PCK C4 pathway. Characterized
germinal edits within the targeted regions upstream of these two genes
ranged in size from 138 bp up to 1790 bp. A 138 bp within the Sb.PEPCK.BS
upstream region and a 1643 bp element within the Sb.AlaAT.BS upstream
region were determined to be important for maintenance of transcription
levels. No change in development or various physiological parameters was
observed in characterized lineages carrying promoter edits. However,
significant changes in seed reserves and a reduction in 100 seed weight
were consistently observed, under both greenhouse and field environments,
in plants carrying an edit in the promoter of Sb.PEPCK.BS gene were
significantly reduced in transcript accumulation for this gene.